Swingarm and rear shock mods?

[BiG DoM]

A while back I read about the rear shock lower bracket mods that were tried (and bello posted CAD link recently) and have also seen extended rear swingarms on rally bikes. I am interested in different opinions on these mods.

My understanding is the raised angle rear shock mount would reduce the front rake making the bike turn quicker … much like a different triple clamp angle. It would also raise the back/seat height a bit. Useful for tighter technical enduro style riding?

The lengthened rear swing arm interests me because I always considered the G450X to already have a long wheelbase and be quite stable in sand and open stuff … this is by my understanding doing the opposite of the shock mount mod. Does anyone know if the lengthened rear swingarm was coupled with a reduced front rake angle on these rally bikes…. not that I am thinking of lengthening! Just curious.

[Campbell]

Dom,
08/09 10
Wheelbase 1475 1475
Trail 119mm 118.8mm
Rake 61deg 61.8deg (There is no standard some manufacturers measure from horizontal others vertical
hence 30deg/60deg are the same rake)

I have not compared wheelbase with other makes but believe it is similar, it is the steering geometry that provides the straight line stability. The longer swingarm incorporated within a standard wheelbase as a result of CTS provides greater traction on hill's.

Straight line stability v quick turning are a direct trade off, you can't have it both ways. The G450X is slightly biased towards high speed Rally/Desert in it's geometry. Having said that as you can see from the changes made to the 2010 model by changing both Rake and offset (Offset = Triple Clamp + Axle) it is possible to maintain Trail (More Trail = more stability) - OK it was reduced by 0.2mm but that is negligible. So what has changed? - Steering effort/Flop/Turn-in, call it what you want but essentially the effort required to change direction has been reduced. I am sure there is a formula for calculating this as there is for Trail, but I don't have it.

"My understanding is the raised angle rear shock mount would reduce the front rake making the bike turn quicker … much like a different triple clamp angle. It would also raise the back/seat height a bit. Useful for tighter technical enduro style riding?"

Typically Triple Clamps have the Forks parallel to the steering axis the offset refers to the centre distance between the two. Typically a 5mm change in Fork height produces a 0.25deg change in Rake, so raising the Forks through the Triple Clamps gives a steeper Rake producing, as you say, quicker turning. A reduction in Race Sag does the same thing, typically a 5mm reduction produces a 0.25deg steeper Rake. (A number of Tests of the 08/09 suggested 95mm Race Sag for tight work.)

The Speedbrain lower shock bracket raises the rear 15mm, steepening the Rake by 0.75deg which is significant.
The dimensions centre to centre are; 70mm vertical, 87.5mm diagonal and 52mm at the base.

I cant open that Cad file for the 6x6 bracket so if anyone can post up the dimensions I would appreciate it.

The extended rear swingarm is purely a high speed stability thing.

I run a TTX44 with the Speedbrain mount and 8mm on the Forks with a low seat for tight stuff, the upside of the mount approach is it can be changed in under 5min, the down side (for me as a short arse) is the extra 15mm.

Edit 16th Nov 15

The following is from a article in Motocross Action Magazine March 10 2015 and although it contains a few errors, is quite well written.

Gottlieb Daimler may have invented the motorcycle in 1885, but when it came to handling, his wooden buck frame and feet-dragging riding style just didn’t cut it. From his founding-father perch 126 years ago, Gottlieb had no way of knowing what AMA professional motocross racers would do with his rudimentary design. When Daimler invented the first motorcycle, his benzene-fueled wooden kludge needed training wheels to help him negotiate the gentle bends of his villages’ cobblestone streets.

The dynamic interplay between a motorcycle’s steering geometry, the gyroscopic effect of its spinning wheels and its center of gravity was not known at the turn of the 19th century. Old man Daimler’s invention, with its vertical fork and tiller handlebar, steered more like a boat than a bike. Today, its direct descendants can negotiate a crowded pit lane in first gear faster than anything in Gottlieb’s world could go in a straight line.

THE WIZARDING WORLD OF FRAME GEOMETRY

Frame geometry is the magic that makes it possible to roost corners, slam berms and survive the whoops. Forget engine technology and set aside suspension, because it wouldn’t be possible to get past second gear without the self-stabilizing forces that are built into a modern motocross chassis. Without the right blend of head angle, trail, fork offset and weight distribution, your motocross machine would be hard pressed to out handle a Walmart shopping cart. In fact, it would need a pair of Gottlieb’s training wheels to get out of its own way.

To understand what motocross bikes are all about, you need a rudimentary understanding of the ins-and-outs of frame geometry. Read on and discover what handling is all about.

WHAT IS CASTER AND WHY IS IT SO IMPORTANT?

“Caster” is the effect that causes the swiveling wheels of a shopping cart to steer in the direction you deflect the cart. Motocross bikes use the same physics of caster as shopping carts.

WHAT IS TRAIL AND WHY IS EVERYONE TALKING ABOUT IT?

“Trail” is what causes the front wheel of a motorcycle (and shopping cart) to align itself with the direction that the vehicle is traveling. Trail exists when the contact patch of the tire is well behind the steering axis.

In the case of a shopping cart, the steering axis is vertical and the axle is offset about an inch behind the axis. When the cart is pushed, the wheels instantly swing into alignment. The same holds true for a motocross bike. Take your hands off the bars, and your motorcycle’s front end will snap into a straight line for the same reason. “Caster” is the effect. “Trail” is what makes it happen.

WHY IS IT CALLED TRAIL?

As will become apparent, trail is called trail because it is derived from an equation that measures how far behind the head angle the tire’s contact patch is. In simple terms, how far the contact patch “trails” the head angle.

Unlike a shopping cart, the steering axis of a motocross chassis is angled, but the fact that its front axle and the tire’s contact point lie well behind the centerline of the fork creates the same trail equation.

WHAT IS HEAD ANGLE?

“Head angle,” “caster angle” and “rake angle” are all the same measurement. Head angle is the difference between the front side of the steering axis and a theoretical line drawn perpendicular to level ground in degrees.

Motorcycles need to be stable at high speed, so it is necessary to slow the steering way down by raking the head angle forward. The degree that the steering axis is raked forward is called the “head angle.” A chassis with a slacker head angle steers less when you turn the handlebar and wants to remain in a straight line (think chopper). A steeper head angle turns quicker, feels lighter at the handlebar and is less stable at speed (think trials bike).

Head angle works in conjunction with “fork offset” to cause the front wheel to steer into a turn when it is leaned and straighten out as you exit.

HOW DO YOU MEASURE HEAD ANGLE?

You measure the head angle from an imaginary line perpendicular to the ground to where it intersects the angle of the steering axis. The numbers are based on a 90-degree right angle. There is some confusion among designers as to which side of the fork the head angle should be measured from. For example, a CRF450’s head angle is listed as 26.52 degrees, because Honda measures it from the front of the fork. But, in the bicycle world, this would be called a 63.48-degree head angle (as measured from the back side of the fork).

The confusion comes when people don’t understand that the head angle is derived off of a 90-degree base number. A 26.52-degree head angle is the same as a 63.48-degree head angle (90-26.52 = 63.48). It is simply two ways of describing the same angle.

WHAT ARE TYPICAL HEAD ANGLES?

Motocross bikes have head angles in the range of 27.5 to 26.0 (62.5- to 64-degrees). A 27.5 head angle is not as steep as a 26-degree head angle. Steeper head angles turn more instantly and in a smaller arc. The slacker the head angle, the more the front wheel will resist turning, the larger the turning arc will be, and the easier it will be to hold a straight line.

Motocross bikes of the ’70s typically had 30-degree (70-degree) head angles. They were called “slack” head angles. Slack is the converse of steep.

HOW IS TRAIL MEASURED IN MOTOCROSS?

It’s a simple measurement: Extend an imaginary line down the center of the steering axis to the ground. Then, drop a perpendicular line through the center of the front axle to the ground. The distance between where the two lines intersect the ground is the trail measurement. As a rule of thumb, it should be between four and five inches.

WHAT EFFECT DOES TRAIL HAVE ON A BIKE?

A longer trail measurement means greater caster effect, heavier and slower steering, and a more stable feel in a straight line. Reducing trail causes the bike to steer lighter and quicker and the front end to feel more nervous in a straight line.

All geometry measurements are taken from a bike that is standing on level ground. At the factory, trail is calculated on an engineering program, taking into consideration what the engineers feel will be the correct static sag setting. Some chassis engineers also refer to trail as “wheel caster.”

WHAT IS FORK OFFSET AND WHY DO PEOPLE CHANGE IT?

Fork offset is the measurement of how far the fork leg sits ahead of the steering axis. To obtain the correct number, measure the distance from the center of the fork leg rearward to the center of the steering stem.

Offset is used primarily to determine the correct amount of trail for a given head angle. Motocross front ends typically use between 18mm and 25mm of trail.

More fork offset reduces trail for a quicker steering feel and less stability. Trail is increased with less fork offset. Fork offset is a term that is used more by aftermarket triple clamp makers, because they offer clamps with various offsets that are used to create handling characteristics that are different from stock.

WHAT’S THE HIDDEN SECRET OF FORK OFFSET?

A little considered fact is the role fork offset plays in the steering process apart from establishing trail. The weight of the wheel and most of the fork is offset above the steering axis, while the wheel contacts the ground behind the steering axis. This creates an interesting relationship. As you lean the bike into a turn, the weight of the bike leaning off to the side automatically forces the wheel to turn into the lean. The more the wheel is offset, the more the fork will steer into a turn when the bike is leaned.

IS IT BETTER TO ADJUST OFFSET AT THE FORK OR AT THE AXLE?

Fork offset can be changed at the triple clamp (by moving the fork legs closer or farther away from the steering stem) or at the axle lug (by casting the lugs so that the front axle is a specific distance away from the center of the fork legs). In 2004, Honda wanted to change the offset on their bikes, but rather than change the triple clamps, they had Showa pull the front axle back 2mm to give the CRFs more trail.

IS IT BETTER TO CHANGE OFFSET AT THE CLAMPS OR AT THE AXLE LUG?

As a rule, changing trail at the axle, as KTM did last year, is better than at the clamps. Why? The more offset at the triple clamps, the more the rider will feel the weight of the fork tubes when steering. Although there needs to be some offset at the clamps to give fork clearance for turning radius, the less offset the better to decrease the fork’s moment of inertia. The lightest steering bikes will put as much of the given offset as possible into the axle clamps.

CAN YOU CHANGE TRAIL BY RAKING THE FORKS?

Yes, but it is rare. Some works triple clamps are designed to angle the fork tubes differently from the head angle. Obviously, raking the forks away from the head angle would increase trail and vice versa. But this is not the way most manufacturers adjust for trail or offset. And, it should be noted that changing the angle of the fork in the triple clamps (by raking them), does not change the head angle of the bike in any way.

The biggest effect of raking the forks, apart from a change in trail, wheelbase and weight bias, is the affect on suspension action. Slacker fork tube angles make the fork less responsive to chatter bumps, flat landings and slap-downs?but more yielding to square-edge and large whoop impacts. Steeper fork tube head angles cause the forks to compress more when braking into corners and react better to flat landings.

WHAT FRAME NUMBERS MAKE A BIKE TURN?

The perfect steering geometry is the correct relationship between the bike’s head angle, weight bias, overall wheelbase, front center (distance from the axle to the crank center), fork offset and trail. Thus, changing one number will affect all the others.

It’s no secret that how the bike is set up can alter the steering geometry. Something as simple as more race sag in the rear shock, a different tire profile or even lower tire pressure can be used to fine-tune the way the front end handles. Any adjustment that drops the rear of the bike will slacken the head angle, slow down the steering and increase the trail measurement. Likewise, trail will be reduced and the steering will feel quicker if you run more shock preload or a larger-diameter rear tire.

HOW IMPORTANT IS WHEELBASE?

Wheelbase is the distance between the front and rear axles. A longer wheelbase turns slower, tracks smoother over rough terrain and is less affected by rider position. Shorter wheelbases are more responsive to weight shifts, turn quickly and ride roughly. Motocross wheelbases typically fall into the 58-inch range.

EXACTLY WHERE IS THE CENTER OF GRAVITY?

The center of gravity is, roughly, the point where the combined mass of the rider and motorcycle are balanced in all directions. Saddle height, the position of the engine within the frame, and ground clearance establish the center of gravity (CG) when the rider is on the bike.

Ground clearance: The amount of ground clearance is largely determined by the amount of suspension travel. To prevent your feet from being swept off the footpegs when the suspension bottoms out, ground clearance will always be an inch or two more than the suspension travel.

Seat height: Motorcycle engineers choose a seat height that positions a rider of average height and weight at a balance point near the center of gravity, where small body movements will have a strong affect on braking, steering and acceleration. If the CG is too low, the rider won’t be able to transfer weight properly over the front or rear of the bike. If the center of gravity is high, too much weight will transfer from front to back during accelerating and braking, causing the bike to bounce all over the place through the bumps.

Engine position: Computer programs are now responsible for engine position. They must factor in not only the weight of the engine, but the gyroscopic effects of its internal motion. Once the computer selects the optimum position, factory test riders confirm it during test sessions.

Changing suspension sag, handlebar height, footpeg location and the thickness of the seat are options for a rider looking at raising or lowering a bike’s center of gravity.

WHAT IS WEIGHT BIAS?

“Weight bias” is how the percentage of total vehicle mass is divvied up between the front and rear wheels. It’s kept as close to a 50/50 bias as possible?with and without the rider on board. With shared bias, it takes less input from the rider to make the front stick in corners or the rear tire hook up out of corners. The rider controls the front/rear weight bias by moving forward or back over the seat.

HOW DOES GROUND CLEARANCE RELATE TO THE OTHER NUMBERS?

Motocross geometry must be built around ground clearance. If you have 12 inches of suspension travel, you need at least 13 inches of ground clearance and a bit more peg height. Bikes with less travel and lower ground clearances will have a lower center of gravity. A lower center of gravity shifts less weight from front to rear when accelerating and braking, and because of this can get away with a shorter wheelbase. But, before you run out and lower your seat and slide the rear axle forward to improve cornering, you must factor in the mass of the vehicle and ask, “How will these changes affect the weight bias?” Remember, moving the rear wheel forward in the swingarm moves the engine backwards.

Among the many mass considerations involved are engine weight, engine position, gas tank volume, fuel position, seating position, footpeg position, overall bike weight, wheel weight, handlebar position, rider weight, and the rated horsepower. One change, say moving the rear wheel forward, will beget many other changes: (1) Moving the rear wheel forward will lessen leverage on the shock and make it feel stiffer. (2) Moving the wheel forward will make the wheelbase shorter, but also change the weight bias from 50/50 to something approaching 45/55 (by moving the gas tank, engine and rider closer to the rear wheel and farther from the front wheel). (3) Moving the rear wheel forward will shorten the wheelbase and make the bike easier to fold into tight turns.

CAN THE ENGINE AND WHEELS AFFECT A BIKE’S HANDLING?

Yes. Horsepower and torque influence weight bias and suspension performance. The rotating inertia inside the engine creates a gyroscopic effect that impacts how much the bike resists turning and how it behaves in the air. High-rpm engines slam bumps harder and need to be mellowed out through frame geometry. A designer must also take into consideration the riding styles that will most likely be used on that displacement bike. Smaller displacement bikes are shorter, quicker turning and more agile to match the way they are ridden.

The weight of the tires and tubes affects cornering. Factory riders can feel the difference between heavy and light tubes. Heavier tubes increase the gyro effect. The heavier spinning weight keeps the bike straighter and more resistant to leaning.

HOW CAN THE WIDTH OF HANDLEBARS AFFECT HANDLING?

The arc, that the ends of the bar form when turned side to side, will be smaller with a narrower bar width. Conversely, wider bars turn a larger arc. That means the rider’s hands move a greater distance to turn the wheel the same amount if his bars are wider.

On the track, narrow bars feel quick and nervous. They also transmit more feedback from the track surface to the rider. Conversely, wider bars slow down the steering input (because the hand movement is longer and slower) and mask some of the feedback that comes from the track through the steering geometry.

Handlebars can also be used to tune the center of gravity. Straighter, more upright bars, or forward-set bar clamps, will move the rider forward on the bike and shift weight bias to the front. Depending on the exact suspension setup, this could make it easier to stick the wheel into corners.

HOW DOES ENGINE SIZE AFFECT THE CHOICE OF STEERING GEOMETRY?

Steering geometry is not the first thing on the designer’s mind. Not until the remainder of the bike has taken shape will the engineer finally decide on the exact steering geometry. With the input of test riders, it will be tuned for quicker or slower steering action, or for more or less stability to best match the characteristics of the bike and rider.

A good comparison is the Honda CRF250 and CRF450. The CRF450 is heavier and faster, with more weight bearing down on the steering axis and front tire. It is powerful, heavy and blessed with greater mass in motion. It must be ridden with more subtlety than a smaller or less powerful bike. The lighter CRF250 doesn’t need to be toned down like its big brother. It weighs less, has less power and less mass in motion. It can get thrown around without biting back. Thus, the CRF250 has a steeper head angle, shorter wheelbase and a half-inch more trail. The combination of a steep head angle and more trail balances the quick steering with more self-straightening action.

The geometry equation used on small displacement bikes prefers quicker turning and greater caster effect to keep the lighter bike and rider more stable. Big powerful bikes, by their very nature, have slacker head angles to avoid oversteer.

WHAT ABOUT WORKS BIKES?

A famous factory rider might be required by the rules to use the same frame that you do, but he can adjust his rake by using eccentric steering bearings, his head angle with longer or shorter shocks, and his offset with different triple clamps. Because factory suspension settings are so stiff, factory riders like to run steeper head angles so the front settles more into corners.

WHAT CAN I DO TO ADJUST THE GEOMETRY ON MY BIKE?

Lots of things:

(1) The weight bias and head angle can be influenced through preload adjustment, suspension settings, bar position and by sliding the forks up and down in the triple clamps. If you make the bike taller in the back and set the controls so the rider weights the front, the bike will turn quicker and be less stable. If it’s taller in the front with a more rearward weight bias, the bike will turn slower and be more stable.

(2)Removing or adding a link in the chain makes it possible to lengthen or shorten the wheelbase. Short wheelbases turn sharper, hook up better out of the corners and feel more nervous. Longer wheelbases are more stable.

(3) Aftermarket triple clamps are available in a wide variety of offsets. Depending on the fork offset, aftermarket clamps can speed up or slow down handling. More offset results in quicker steering. Less offset makes the steering heavier but more controlled.

(4)The center of gravity moves every time the rider moves. Rear set footpegs can take the load off the front of a bike, slow the steering input and change the weight bias rearward.

(5) Aftermarket shock linkage can lower the rear of the bike to kick the head angle out. The rider can then raise or lower the forks to choose the head angle that he wants?while also lowering the center of gravity.

SHOULD YOU CHANGE YOUR BIKE’S GEOMETRY?

Yes. MXA test riders do it all the time. It was MXA who pioneered offset changes on late-model KTM and Honda CRF frames (changes that the factory incorporated over time). It was MXA that cut the 1979 Honda CR125 in half to change the head angle so that the oddball 23-inch front wheel could be dumped. It was MXA that railed against rearward bar mounts. You can follow MXA‘s lead with small steps. For example, if you have a problem with head shake, try sliding your fork legs down in the clamps to slacken the head angle. You are only a victim of your bike’s handling characteristics if you don’t understand them.

That said, a lot of testing and engineering went into the frame geometry of the modern motocross bike. Small changes will make a big difference in the way your bike handles. But, if you start messing with every aspect of your frame’s geometry, come race day, you might get lapped by the ghost of Gottlieb Daimler.

And my pet subject also from the same magazine a few years back.


DEATH OF THE RISING RATE
July 13, 2000
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Rising-rate shock linkages are a scam. This so-called innovation has been foisted on American motocross racers for the last 20 years with little or nothing to recommend it. It’s not that rising-rate linkages don’t work; it’s just that they don’t work as advertised, don’t work better than other alternatives and are too complex for what little they do.
The nail is in the coffin of rising-rate linkages, but the funeral will be put off until every motorcycle manufacturer in the world can’t feel the pulse any more. Not surprisingly, that could take years.



WHAT’S GOING TO REPLACE THEM?


If rising-rate linkages are dead, what’s going to replace them? That’s simple! No-link, single-sided shocks. What’s a no-link, single-sided shock? Exactly what it sounds like.
“No-link” means that instead of latching the shock absorber to a complicated series of pulleys, leverage arms and bell cranks, the shock of the future will be attached directly between the swingarm and frame (just like in the good old days).
The lone shock absorber (unlike the good old days) will be mounted on one side of the swingarm.



WHAT’S RIGHT ABOUT NO-LINK SYSTEMS


In a word-simplicity. A no-link shock can achieve all of the positive things that a rising-rate linkage system can, including having a rising rate, with one-tenth the parts. The benefits of this simple design pay dividends throughout the whole machine.



WEIGHT SAVINGS THAT CAN’T BE BEAT


KTM’s 520SX four-stroke weighs 12 pounds less than the Yamaha YZ426. While some of this weight is saved through careful engine design, a large portion of it came from KTM’s no-link shock eliminating the need for shock linkages, bearings, bushings, dust seals, frame bracketry and beefed-up frame tubes.



MORE FUEL AT A HIGHER VELOCITY


If you want to optimize fuel atomization from the carburetor to the top end, you would design a perfectly straight intake tract. Engine management specialists have spent years developing the perfect shape, diameter and length of the intake to maximize horsepower, only to have the whole formula ruined by a shock absorber blocking access to the intake tract.
A quick look at modern single-shock, rising-rate-linkage motorcycle designs will reveal that the carburetors are mounted askew and the intake tract has a curve in it. Thanks to the fundamentals of flow (based on Bernoulli’s Principle), a curved intake wreaks havoc on the delivery of the fuel air mixture. How much havoc? There is a 25 percent decrease in laminar flow through a curved intake tract versus a straight one. That translates into lost power.
With a single-sided, no-link suspension system, the shock does not block the intake tract. Instead, a single-sided shock absorber is mounted off to the side, allowing the fuel/air mixture a straight shot through the intake tract.



THE END OF RISING-RATE RETRACTIONS


If you are an aficionado of press releases, you already know that rising-rate leverage ratios are changed almost every year. This endless merry-go-round of leverage ratios started in 1980 (when Kawasaki’s Uni-Trak system was introduced to the public, only to turn out to be a falling-rate rear suspension system) and has gone unabated into the current century. Every year, suspension engineers make the linkage less progressive in the first one-third of travel, or more progressive in the last half of travel, or increase the rate change through the middle. Then, the next year, they reverse themselves and go the other direction. After 20 years of yo-yoing, you’d think they would come to the realization that they don’t know what they are doing.



COMPLEX IS AS COMPLEX DOES


Linkages lift the shock at ever-increasing speeds by compressing the shock at progressively greater amounts (for the same amount of rear wheel travel). Since the shock moves faster and farther at the end of the stroke than it does at the beginning of the stroke, its damping increases. Linkages, for all their mysterious allure, can be explained in this simple homespun way-you can’t stuff a large pig through a hole in the fence as fast as you can a small one. Thus, rising-rate linkages change the rate (read speed) at which the shock travels as the rear wheel moves. They speed it up, which slows it down (because the pig gets stuck in the hole).



WHAT HAPPENS TO THE NO-LINK’S PIG?


Guess what? The same thing happens if you mount the shock to the swingarm without the linkage. Don’t obsess on the lack of a rising-rate linkage on a no-link bike. Linkage doesn’t mean much in the real world. It is possible for a no-link suspension system to duplicate the rising-rate of most successful leverage ratios by positioning the shock within the known framework of a scalene triangle (a scalene triangle is one in which all three sides have different lengths and angles). However, from a mathematical standpoint, it is not completely possible to get the same rising rate from a no-link system as on a bellcrank linkage. There are rates that have a severe rising curve in the middle of travel that no-links can’t duplicate (luckily, these are not curves that many manufacturers would use anyway).
Making the rising-rate spoof even more ludicrous is that modern rising-rate bikes use the same approximate leverage ratio as the twin-shock Suzukis that Roger DeCoster used to race. So much for progress!

Edit; to put some figures around this motocross bikes yo-yo around 20>24%, the KTM PDS was 11% and the G450X achieves the maximum mathematically achievable at 20% from a scalene triangle, as a result of a frame design that has freed up shock placement.



A LITTLE HISTORY


Rising-rate linkages are not new, but if you’re looking for the father of the idea, you have to go back to the early ?70s and New England inventor Joe Bolger. Long-travel suspension was a new movement in the ?70s, but as racers started moving their shocks forward on their swingarms, they discovered that the spring rates weren’t stiff enough. As they went from four inches of travel to seven inches, the bike bottomed out. Why? The leverage the swingarm applied to the shocks was dramatically changed when the shocks were moved forward. With the shock moved forward, the swingarm became a pry bar that overpowered the 110-pound shock springs that were de rigeur in the ?70s.
The solution was to put stiffer springs on the shocks. Unfortunately, the spindly little oil-damped, non-nitrogen shocks of the day didn’t lend themselves to 275-pound springs. That’s when Joe Bolger got the idea of mounting the shocks on his Ossa all the way forward and mitigating the leverage of the long swingarm with rocker arms.
Joe Bolger invented the modern suspension system that we use today. Unfortunately, he didn’t get rich off of it. Bolger’s idea didn’t catch on. Instead, a Belgian designer named Lucien Tilkens came up with the idea of mounting a single, larger, longer shock under the gas tank. The longer shock could be properly sprung and would have enough shaft travel to handle the demand for increased rear wheel travel. Tilkens put his single-shock on a CZ and tried to talk countryman Roger DeCoster into getting Suzuki to buy the idea. Suzuki dawdled, Yamaha bought Tilkens’ idea and the monoshock was born.
Although the monoshock was a successful marketing idea, it wasn’t the greatest working suspension set-up in the world (nor would it classify as a rising-rate linkage). Yamaha’s Hakan Andersson won the 250 World Championship as soon as he switched to the new single-shock Yamaha, but it turned out that the bike’s long travel made it a success-not its lone shock absorber.



IN SEARCH OF MARKETABILITY


By the early ?80s, all of the manufacturers jumped on the single-shock bandwagon. A single shock had some advantages over the twin-shocks of the day. (1) They had less swept seal area. One big seal was better than two small seals, and the result was less stiction. (2) As carbon and nitrogen-charged shocks became more refined, they required more and more capacity. It was simpler to make one big shock than two medium-sized ones. (3) Suspension travel was increasing every year. By 1981 it looked like the bike of the future might have 14 inches of rear wheel travel. It didn’t come true, but the prediction had designers thinking of ways to handle the ever increasing loads. One massive shock, with a beefy shock shaft and over-sized piston, seemed like the best path to follow.



THE MARRIAGE OF BOLGER AND TILKENS


To make single-shock bikes work, Japanese designers locked on to the previous work of Bolger and Tilkens. They married Tilkens’ single-shock idea with Bolger’s rocker arm linkage and the rest is history. In time, every manufacturer had dropped its twin-shock design for a single shock, rising-rate linkage system (although Husqvarna resisted longer than anyone else).
Uni-Track, Pro-Link, dog bone and Full Floater became part of the vernacular, and the merry-go-round was in motion. Starting with the falling-rate (something that you definitely don’t want) of the first Kawasaki Uni-Trak, through the broken Corte Cossa shocks of the 1982 Maicos, to the sad demise of the Full Floater, all bikes soon became clones of each other. Copying, borrowing, rethinking and second-guessing have been the hallmarks of rising-rate shock theory.



BOLGER AND TILKENS’ ANTITHESIS


If Bolger and Tilkens were the proud parents of the suspension system that we have used for the last 20 years, who’s the progenitor of the no-link, single-sided suspension system? That’s a no-brainer! Horst Leitner, an Austrian-born American citizen, never believed in the rising-rate hullabaloo. When he penned the design for his first ATK four-stroke back in 1981, he mounted the single shock on the side and skipped the linkage. Honda even made copies of Horst’s frames for Ron Lechien and Johnny O’Mara to ride at the 1984 World Four-Stroke Championship. In 1990, KTM’s management paid Horst, who by then had sold ATK and gone into the mountain bike business, to build them a prototype motocross bike. The bike he delivered to the Austrian factory was a single-sided, no-link, perimeter-framed machine that was years ahead of its time. How many years ahead of its time? Six. Horst’s bike disappeared into the bowels of KTM’s Mattighoffen, Austria, factory, only to reappear in 1997 as the new no-link, single-sided PDS system.
The KTM PDS design was the first blow to rising-rate linkages. At first, it was only a superficial wound, largely because KTM’s shock valving was so far off the deep end that the rear suspension barely moved. But the damage was done.



NOT THAT LINKAGES WON’T WORK


Rising-rate linkages can be made to work. For 2000, Yamaha has the best showroom-stock suspension system. Not because Yamaha has a better rising-rate linkage than the other manufacturers, but for a more logical reason. Lack of action! In fact, Yamaha’s success is due to the fact that they haven’t changed their rising-rate in recent years (not that they haven’t changed it innumerable times in the past). How can not changing the rising rate result in improved suspension performance? It focused the available development time on the shock (where real gains can be made). Yamaha was able to make changes to their damping and spring rates that could actually be applied to a non-moving target. By not changing the rising rate, they didn’t shift all the variables and end up using guesswork on their damping. The lesson? Every time the engineers change a linkage’s rising-rate, they throw out all the previous testing, development and damping know-how. In essence, they start with a blank sheet of paper. Yamaha decided to work with what they had and make it better.



WHEN IS THE FUNERAL?


Honda, Yamaha, Suzuki and Kawasaki think they can make their rising-rate suspension systems work and 20 years of hit-and-miss failure hasn’t deterred their optimism. But the real question is, why persist with a system that puts the rest of the machine at a disadvantage? A no-link design can save valuable weight (especially important on four-strokes), make room for larger air boxes (engines are, in their basest form, air pumps), allow for perfectly straight intake tracts (eliminating the bugaboos of flow turbulence and scrubbing), improve maintenance (everything from preload adjustment to shock removal is simplified), lower production costs (which is why the incredible Full Floater was circular-filed 17 years ago), enable the press-release flacks to unveil a new flurry of adjectives (which is almost as good as real improvements) and offer better rear suspension performance in the long run (since suspension will become more shock dependent).
Rising-rate linkages are dead-please send flowers.

[BiG DoM]

Thanks that really confirms and clarrifies a few things.

[bello650]

I cant open that Cad file for the 6x6 bracket so if anyone can post up the dimensions I would appreciate it.

Look on web for sldprt free viewer (SolidWorks Part File (SolidWorks Corporation) with free trial

[Tims1572]

Dom,
I've seen a few different rear shock mounts made up to accept the use of a shock similar to a KTM shock with an open Clevis end. The pictures I've seen were of Supermoto guys mostly but even the Blue framed bike below has a swing arm mount milled out of a block of aluminum to do this. I know you have the Trax shock now but this is an option for modifying the rear suspension by using a much more readily available KTM WP Unit.




Also notice the head stay mount and the bolt through the frame that Pascal had mentioned on the right side that is connected to the normally unused tapped boss in the cylinder we have used to mount breather tanks. Also notice the left side where the fuel tank sump no longer lines up with the mount on that side and a drop down bracket was made.

If you notice the geometry of the frame where the top engine mount comes from the frames side forging and leads up to the head of the frame it has quite a different angle to it and a dogleg as well to get the engine moved forward. The frame also has a cross tube between the side forgings just above the top of the rear of the engine near the lower subframe mounts. Also looks like that might be the battery mounted down at the rear of the engine in the opening in front of the swingarm.

Engine appears to have an adjustable cam chain tensioner as well.

This shocks base is now moved forward and is going more of an angle upright than being laid down farther like Andrew Gores 6x6 mount.







I also had a talk with a BMW engineer about the engine moving (forward +60mm), asking why, the geezer said.... 2because we can"...... I was impressed!







And the hydraulic clutch kit..... it works for some!

[bello650]

Also looks like that might be the battery mounted down at the rear of the engine in the opening in front of the swingarm.









I also had a talk with a BMW engineer about the engine moving (forward +60mm), asking why, the geezer said.... 2because we can"...... I was impressed!







And the hydraulic clutch kit..... it works for some!

You are right Tim
The last picture we see the battery terminal and the other picture we see red and black wires for the battery
We see that the air box input does not correspond with the cutting of the plastic cover,that's the reason the move the battery.
On the swingarm see the scratches the brake master cylinder which rubbed.
These are the same scratches that I had when my left bearing swingarm was broken.
http://g450riders.org/forum/attachme...5&d=1338505220
http://g450riders.org/forum/showthre...270#post647270

[Tims1572]

Shifter and brake pedal have also been shortened. My swingarm has a few rub marks like that also. If the swingarm isn't shifted fully to the left before tightening it will do this.

[Campbell]

A bit of info I came across re the above Blue Frame machines.

News 21 May 2010
Alex Gobert
WEC: BMW Husqvarna Motorsport to debut prototype in Italy
Share

Section: News Post: Alex Gobert
Tarkkala will be on a BMW Husqvarna prototype in Italy this weekend.



Tarkkala will be on a BMW Husqvarna prototype in Italy this weekend.

BMW Husqvarna Motorsport is preparing to send a prototype bike into action for the first time in the upcoming round of the FIM World Enduro Championship (WEC) in Lovere, Italy, this weekend.

The bike, which will compete in the E2 class at the event, is built around the Husqvarna chassis concept and powered by the innovative and highly capable 450 cc four-stroke engine developed by BMW Motorrad.

“Back in February we signed up to race in the E2 class of the Enduro World Championship under the new name BMW Husqvarna Motorsport,” explained Rainer Thoma, president and CEO of Husqvarna Motorcycles. “This collaboration of BMW Motorrad and Husqvarna Motorcycles aims to pool the two brands’ expertise in off-road competition for 450cc four-stroke machines.

“The forthcoming debut appearance of the prototype bike is the logical next step following a very promising phase of testing. Although our leading rider Juha Salminen will have to sit out this coming weekend through injury, we’re approaching the event in optimistic mood with our prototype bike, our other regular rider Marko Tarkkala and stand-in man Andreas Lettenbichler.”

Over the past few months, the people at the Husqvarna Motorcycles development department have been working closely with specialists at BMW Motorrad and Speedbrain to develop a bike combining the Husqvarna chassis concept with the innovative and accomplished 450cc four-stroke engine developed by BMW Motorrad.

The testing phase, which got underway at the start of the year, is now completed, and the bike will be entered in competition from this weekend.

“Our aim for the 2010 season was to be fighting for the title in the E2 class of the Enduro World Championship with the BMW Husqvarna Motorsport team,” adds BMW Motorrad motorsport director Berthold Hauser. “With Juha’s injury and his absence from the next race as a result, that’s going to be tough.

“In order to be successful despite this setback, it’s imperative that we make best possible use of the available synergies. With the testing phase completed the aim now is to use this genuine Husqvarna with BMW G 450 X drive concept to be up there fighting for success and victories in the sporting arena.”

BMW Motorrad Motorsport will remain actively involved in off-road competition with the BMW G 450 X. The team is planning to continue racing the bike in the European and the German Cross Country Championship and a range of Extreme Enduro events.

Meanwhile, the Husqvarna CH Racing team will continue to compete in the E1 and E3 classes of the FIM Enduro World Championship. The Supermoto and Motocross segments will also remain under the Husqvarna banner.

Also this press release;

Off-road team to race under the name "BMW Husqvarna Motorsport".
Evolutionary entrant in the FIM Enduro World Championship.

Munich/Cassinetta. The 2010 season will see BMW Motorrad Motorsport lining up in the E2 class of the FIM Enduro World Championship under the name "BMW Husqvarna Motorsport". The reason for signing up with the FIM under this new name is to achieve a targeted pooling of off-road racing expertise by the two brands BMW Motorrad and Husqvarna Motorcycles in the area of 450 cc four-stroke engines. The aim is to set up an ideal knowledge transfer through this sporting involvement, while at the same time optimising the team's performance.

Rainer Thoma, President and CEO of Husqvarna Motorcycles, explains: "In order to achieve sustainable economic as well as sporting success, it is essential to exploit synergies as best we can. That is why we are now collaborating intensively with our colleagues at BMW Motorrad. We are pooling the enormous expertise of both brands: know-how from BMW Motorrad will flow to Husqvarna and vice-versa."

The BMW Husqvarna Motorsport team is set to live up to this target: it will be entering the season with the BMW G 450 X under the team management of Speedbrain. In parallel with this, over the course of the season Husqvarna Motorcycles will be working together with specialists from BMW Motorrad and Speedbrain to develop a machine based on the Husqvarna frame/chassis concept and coupled with the 450 cc four-stroke engine developed by BMW Motorrad. Following extensive trials, the team plans to deploy the motorcycle in the ongoing event.

BMW Motorrad Motorsport Director Berthold Hauser adds: "Our goal is clear: with the BMW Husqvarna Motorsport team we intend to compete for the title in the E2 class of the 2010 Enduro World Championship. Our E2 class runner-up result in the drivers' and manufacturers' championship, our win in the Red Bull Romaniacs and many more triumphs and podium places around the world bear witness to the potential of the BMW G 450 X concept and the team's outstanding work in the season just past. Our joint involvement in enduro racing now provides the ideal platform on which to test how an authentic Husqvarna with the BMW G 450 X drive concept acquits itself in the competitive arena."

Team Husqvarna CH Racing will continue to run in the E1 and E3 class of the FIM Enduro World Championship. The Supermoto and Motocross segments will also remain under the Husqvarna banner.
For any queries please contact:

Benjamin Titz, BMW Sports Communications,
phone: +49 89 382 22998, mobile: +49 179 7438088

Martino Bianchi, Husqvarna Communications,
phone: +39 0332756405, mobile: +39 3357466508

[Tims1572]

A bit of info I came across re the above Blue Frame machines.

News 21 May 2010
Alex Gobert
WEC: BMW Husqvarna Motorsport to debut prototype in Italy
Share

Section: News Post: Alex Gobert
Tarkkala will be on a BMW Husqvarna prototype in Italy this weekend.



Tarkkala will be on a BMW Husqvarna prototype in Italy this weekend.

BMW Husqvarna Motorsport is preparing to send a prototype bike into action for the first time in the upcoming round of the FIM World Enduro Championship (WEC) in Lovere, Italy, this weekend.

The bike, which will compete in the E2 class at the event, is built around the Husqvarna chassis concept and powered by the innovative and highly capable 450 cc four-stroke engine developed by BMW Motorrad.

“The forthcoming debut appearance of the prototype bike is the logical next step following a very promising phase of testing. Although our leading rider Juha Salminen will have to sit out this coming weekend through injury, we’re approaching the event in optimistic mood with our prototype bike, our other regular rider Marko Tarkkala and stand-in man Andreas Lettenbichler.”

Over the past few months, the people at the Husqvarna Motorcycles development department have been working closely with specialists at BMW Motorrad and Speedbrain to develop a bike combining the "Husqvarna chassis concept" with the innovative and accomplished 450cc four-stroke engine developed by BMW Motorrad.

The testing phase, which got underway at the start of the year, is now completed, and the bike will be entered in competition from this weekend.

“In order to be successful despite this setback, it’s imperative that we make best possible use of the available synergies. With the testing phase completed the aim now is to use this "genuine Husqvarna" with BMW G 450 X drive concept to be up there fighting for success and victories in the sporting arena.”


Also this press release;

Off-road team to race under the name "BMW Husqvarna Motorsport".
Evolutionary entrant in the FIM Enduro World Championship.

Munich/Cassinetta. The 2010 season will see BMW Motorrad Motorsport lining up in the E2 class of the FIM Enduro World Championship under the name "BMW Husqvarna Motorsport". The reason for signing up with the FIM under this new name is to achieve a targeted pooling of off-road racing expertise by the two brands BMW Motorrad and Husqvarna Motorcycles in the area of 450 cc four-stroke engines. The aim is to set up an ideal knowledge transfer through this sporting involvement, while at the same time optimising the team's performance.

Rainer Thoma, President and CEO of Husqvarna Motorcycles, explains: "In order to achieve sustainable economic as well as sporting success, it is essential to exploit synergies as best we can. That is why we are now collaborating intensively with our colleagues at BMW Motorrad. We are pooling the enormous expertise of both brands: know-how from BMW Motorrad will flow to Husqvarna and vice-versa."

The BMW Husqvarna Motorsport team is set to live up to this target: it will be entering the season with the BMW G 450 X under the team management of Speedbrain. In parallel with this, over the course of the season Husqvarna Motorcycles will be working together with specialists from BMW Motorrad and Speedbrain to develop a machine based on the( "Husqvarna frame/chassis concept") and coupled with the 450 cc four-stroke engine developed by BMW Motorrad. Following extensive trials, the team plans to deploy the motorcycle in the ongoing event.

BMW Motorrad Motorsport Director Berthold Hauser adds: "Our goal is clear: with the BMW Husqvarna Motorsport team we intend to compete for the title in the E2 class of the 2010 Enduro World Championship. Our E2 class runner-up result in the drivers' and manufacturers' championship, our win in the Red Bull Romaniacs and many more triumphs and podium places around the world bear witness to the potential of the ("BMW G 450 X concept") and the team's outstanding work in the season just past. ("Our joint involvement in enduro racing now provides the ideal platform on which to test how an ("authentic Husqvarna") with the ("BMW G 450 X drive concept") acquits itself in the competitive arena.")

Interesting find "Campbell", Sorry I mistakenly though it was "Pascal".
I picked apart the press statement above and broke down the statements and quotes a bit above and added and a few extra quote marks " " and a few parenthesis ( ) around these quotes, about this bike being a ("BMW/HUSQVARNA prototype"). The funny thing is they mention a few times of the ("Genuine Husqvarna Frame") and the ("BMW G450X drive concept") and these bikes were neither a ("BMW designed Coaxial drive system") and the frame was nothing like a ("Husqvarna") that did go with the what they called ("CTS Coaxial Traction system"). Right into 3 years of production. Claiming fame to coming up with the ("Now called CTS System at the time"). Where these "Blue Framed Bikes" were the modified BMW frames with the engine moved forward.?? Like "Speedbrain rallye" bikes are still using.

This clearly shows "Speedbrains" influence and total involvement as they have kept the "Cradleless" frame concept to this day and near all of these later Rallye bikes from "Speedbrain" have the engine moved forward of the "Swingarm/drive sprocket pivot" as well. With even the "Husqvarna" powered "Speedbrain team bikes".

So I surmise these guys weren't collaborating with each other. It looks more like these Blue framed BMW modified frames were developed for these bikes not by BMW/Husky's Development Dept. coming up with anything genuine nothing. It shows only, at this time of BMW/Husky's transition, They were clearly getting all their information to build these prototypes from Speedbrain.

[bello650]

Interesting find Pascal.
I picked apart the press statement above and broke down the statements and quotes a bit above and added and a few extra quote marks " " and a few parenthesis ( ) around these quotes, about this bike being a ("BMW/HUSQVARNA prototype"). The funny thing is they mention a few times of the ("Genuine Husqvarna Frame") and the ("BMW G450X drive concept") and these bikes were neither a ("BMW designed Coaxial drive system") and the frame was nothing like a ("Husqvarna") that did go with the what they called ("CTS Coaxial Traction system"). Right into 3 years of production. Claiming fame to coming up with the ("Now called CTS System at the time"). Where these "Blue Framed Bikes" were the modified BMW frames with the engine moved forward.?? Like "Speedbrain rallye" bikes are still using.

This clearly shows "Speedbrains" influence and total involvement as they have kept the "Cradleless" frame concept to this day and near all of these later Rallye bikes from "Speedbrain" have the engine moved forward of the "Swingarm/drive sprocket pivot" as well. With even the "Husqvarna" powered "Speedbrain team bikes".

So I surmise these guys weren't collaborating with each other. It looks more like these Blue framed BMW modified frames were developed for these bikes not by BMW/Husky's Development Dept. coming up with anything genuine nothing. It shows only, at this time of BMW/Husky's transition, They were clearly getting all their information to build these prototypes from Speedbrain.

Tim, it's not me, it's Campbell
Pascal

[Tims1572]

Tim, it's not me, it's Campbell
Pascal

Sorry My Mistake.

[bello650]

A bit of info I came across re the above Blue Frame machines.

News 21 May 2010
Alex Gobert
WEC: BMW Husqvarna Motorsport to debut prototype in Italy
Share

Section: News Post: Alex Gobert
Tarkkala will be on a BMW Husqvarna prototype in Italy this weekend.



Tarkkala will be on a BMW Husqvarna prototype in Italy this weekend.

BMW Husqvarna Motorsport is preparing to send a prototype bike into action for the first time in the upcoming round of the FIM World Enduro Championship (WEC) in Lovere, Italy, this weekend.

The bike, which will compete in the E2 class at the event, is built around the Husqvarna chassis concept and powered by the innovative and highly capable 450 cc four-stroke engine developed by BMW Motorrad.

“Back in February we signed up to race in the E2 class of the Enduro World Championship under the new name BMW Husqvarna Motorsport,” explained Rainer Thoma, president and CEO of Husqvarna Motorcycles. “This collaboration of BMW Motorrad and Husqvarna Motorcycles aims to pool the two brands’ expertise in off-road competition for 450cc four-stroke machines.

“The forthcoming debut appearance of the prototype bike is the logical next step following a very promising phase of testing. Although our leading rider Juha Salminen will have to sit out this coming weekend through injury, we’re approaching the event in optimistic mood with our prototype bike, our other regular rider Marko Tarkkala and stand-in man Andreas Lettenbichler.”

Over the past few months, the people at the Husqvarna Motorcycles development department have been working closely with specialists at BMW Motorrad and Speedbrain to develop a bike combining the Husqvarna chassis concept with the innovative and accomplished 450cc four-stroke engine developed by BMW Motorrad.

The testing phase, which got underway at the start of the year, is now completed, and the bike will be entered in competition from this weekend.

“Our aim for the 2010 season was to be fighting for the title in the E2 class of the Enduro World Championship with the BMW Husqvarna Motorsport team,” adds BMW Motorrad motorsport director Berthold Hauser. “With Juha’s injury and his absence from the next race as a result, that’s going to be tough.

“In order to be successful despite this setback, it’s imperative that we make best possible use of the available synergies. With the testing phase completed the aim now is to use this genuine Husqvarna with BMW G 450 X drive concept to be up there fighting for success and victories in the sporting arena.”

BMW Motorrad Motorsport will remain actively involved in off-road competition with the BMW G 450 X. The team is planning to continue racing the bike in the European and the German Cross Country Championship and a range of Extreme Enduro events.

Meanwhile, the Husqvarna CH Racing team will continue to compete in the E1 and E3 classes of the FIM Enduro World Championship. The Supermoto and Motocross segments will also remain under the Husqvarna banner.

Also this press release;

Off-road team to race under the name "BMW Husqvarna Motorsport".
Evolutionary entrant in the FIM Enduro World Championship.

Munich/Cassinetta. The 2010 season will see BMW Motorrad Motorsport lining up in the E2 class of the FIM Enduro World Championship under the name "BMW Husqvarna Motorsport". The reason for signing up with the FIM under this new name is to achieve a targeted pooling of off-road racing expertise by the two brands BMW Motorrad and Husqvarna Motorcycles in the area of 450 cc four-stroke engines. The aim is to set up an ideal knowledge transfer through this sporting involvement, while at the same time optimising the team's performance.

Rainer Thoma, President and CEO of Husqvarna Motorcycles, explains: "In order to achieve sustainable economic as well as sporting success, it is essential to exploit synergies as best we can. That is why we are now collaborating intensively with our colleagues at BMW Motorrad. We are pooling the enormous expertise of both brands: know-how from BMW Motorrad will flow to Husqvarna and vice-versa."

The BMW Husqvarna Motorsport team is set to live up to this target: it will be entering the season with the BMW G 450 X under the team management of Speedbrain. In parallel with this, over the course of the season Husqvarna Motorcycles will be working together with specialists from BMW Motorrad and Speedbrain to develop a machine based on the Husqvarna frame/chassis concept and coupled with the 450 cc four-stroke engine developed by BMW Motorrad. Following extensive trials, the team plans to deploy the motorcycle in the ongoing event.

BMW Motorrad Motorsport Director Berthold Hauser adds: "Our goal is clear: with the BMW Husqvarna Motorsport team we intend to compete for the title in the E2 class of the 2010 Enduro World Championship. Our E2 class runner-up result in the drivers' and manufacturers' championship, our win in the Red Bull Romaniacs and many more triumphs and podium places around the world bear witness to the potential of the BMW G 450 X concept and the team's outstanding work in the season just past. Our joint involvement in enduro racing now provides the ideal platform on which to test how an authentic Husqvarna with the BMW G 450 X drive concept acquits itself in the competitive arena."

Team Husqvarna CH Racing will continue to run in the E1 and E3 class of the FIM Enduro World Championship. The Supermoto and Motocross segments will also remain under the Husqvarna banner.
For any queries please contact:

Benjamin Titz, BMW Sports Communications,
phone: +49 89 382 22998, mobile: +49 179 7438088

Martino Bianchi, Husqvarna Communications,
phone: +39 0332756405, mobile: +39 3357466508

Blue frame in action 22 june 2010, dry break fuel system ???
http://bmwmcmag.com/2010/06/kirssi-c...e-xcc-victory/

Not sure but the gear shift is shortened and chain motor guard are visible, new prototype frame ?

[Tims1572]

I believe Kirssi's bike uses the same frame. As the above blue frames with the engine moved forward. Or you wouldn't see the chain guard case saver.

If you notice also in the way above detailed pictures when these frames were modified the entire forged section was cut away and fabricated, first a piece of tube going up and at an increased angle. Then new capped ended pieces of tube were made that are cupped end tubes to take the motor mount bolt. There is no part of the original forgings forward of the swingarms pivot being used at all to alter that motor mount way forward.

These are the pieces that the upper motor mount bolt goes through, that join the frame tubes back together at different angles. The stock frame section there is part of the entire forging and isn't near that deep. Using long bushings and a longer bolt for the top motor mount.

These fabricated tubes are much deeper and used very short spacer bushings on the top motor mount bolt. The top motor mount bolt is then shorter as well all together.

I'm talking about the one behind the cylinder. It does not use long tapered conical shaped spacer bushings like the stock frame does. The bushing spacers for the motor mount itself on these frames are very short and the tubes on the frame are deeper, on the right side especially. Its long and is very deep. you can't even see the bolts head in there.

Notice also the old Akrapovic headpipe was a slip flange and spring arrangement. Not a bolt up flange similar to a Leo Vince' or the stock headpipes. Or the Akrapovic head pipes, like the ones made later without the Helmholtz Resonators.

[bello650]

noticed also on the engine, the chain tensioner seems adjustable

[Tims1572]

Yes you are right Pascal, I noticed that and mentioned that myself in post number 5 of this thread. Seems like a very fine pitch thread too on that adjuster.

[Campbell]

Yes you are right Pascal, I noticed that and mentioned that myself in post number 5 of this thread. Seems like a very fine pitch thread too on that adjuster.

The cover bolts adjacent to the foot peg area of the frame have been replaced with counter sunk cap screws to enable Torque limiter changes without dropping the engine. There is a post on ADV regarding this mod with the standard frame.

[Tims1572]

Campbell, The Husky engine already has a few of the hardest to get to bolts countersunk already from the factory. The 3 hardest to get to rear ones. I've done this to my engine case myself and here is the wrench I made and use to get to them. It looks like when they moved the engine forward they made it harder to get to the upper bolt that is now also countersunk. The one just above and in front of the countershaft bore.

I've used this small Flatbar Allen wrench to access them. The wrench was made from the short stub cut off the standard Allen key pictured. The shortened Allen key will work too but not as well.

The cut off stub of the Allen key was then just rosette welded with a tig welder into a drilled hole in the strip of metal. Then ground flush. It could be still ground on the hexed side to fit flat with the head of the screw a little but that hasn't even proved to be needed. It will get in there now easily and I just use a over all length shorter fastener which I ground a bit short myself. The picture with the G450 engine laying on its side. ( no 6 photo) shows one of the offending fasteners positions with the new tapered flush head Allen screws in the case just before countersinking. Once this is done the case can be removed although its still a pain in the arse.

The black engine in the frame is the Husky, the top one of the three bolts is still accessible but the bottom 2 are countersunk from the factory with different fasteners that don't stick out and aren't as hard to get out in the frame as the stock hex headed longer standard bolts. Once they are out I just ground them off a little in length as well so they are easier too get in and out. Luckily, I haven't had to deal with this Torque Limiter change again since adding my breather tank / recovery system and ZipTy rocker box breather.

[Campbell]

I came across this BMW Motorrad site which has a fairly complete record of results in the various competitions they entered starting from the 2007 developmental stage through to the end of the 2010 WEC season. Including the Extreme Enduro events and later Dakar.

Interesting to see they only campaigned the above blue framed bikes for a few rounds of the 2010 WEC before commencing development of the TE449, however the blue framed bikes continued as the weapon of choice in most other competitions. Andreas Lettenbichler continued to use the original G450X CTS frame to great effect in the extreme events.

Given that many of the links to various BMW Motorrad sites are now broken, is there some way we can retain this info as a sticky?

Might be a job for Pascal.....you can thank me later.

http://www.bmw-motorrad.nl/nl/nl/ind...=280&notrack=1

[Tims1572]

Campbell, I agree with you on retaining this reference. So I have made the entire thread a sticky.Anyone can still post or add to it.

Good find by the way. I like it, that's quite a list. I had never seen so many mentions of the bikes in competition.

I double checked the link to make sure its active.

Its now at the top of the list as a sticky.

I can only stick the entire thread not individual posts.

Thanks, Timmy

[Campbell]

Campbell, I agree with you on retaining this reference. So I have made the entire thread a sticky.Anyone can still post or add to it.

Good find by the way. I like it, that's quite a list.I had never seen so many mentions of the bikes in competition.

I double checked the link to make sure its active.

Its now at the top of the list as a sticky.

I can only stick the entire thread not individual posts.

Thanks, Timmy

Kind of makes a mockery of David Knight's dummy spit and bad press by the ignorant doesn't it, even up and coming young 18 year old Aussie riders 'did alright' on the G450X.

http://www.bmw-motorrad.com/com/en/i...ews.jsp&id=506

http://bmwmcq.org.au/cms/index.php?o...id=50:showcase

http://motoaus.com/dirt/dirt-news-an...n-enduro-team/

[Campbell]

Blue frame in action 22 june 2010, dry break fuel system ???
http://bmwmcmag.com/2010/06/kirssi-c...e-xcc-victory/

Not sure but the gear shift is shortened and chain motor guard are visible, new prototype frame ?

Pascal, yes dry break system there is a good photo in one of the GCC? Race reports during a re-fueling pit stop. Clearly shows the bung pulled back with a tab and Dry Break can inserted. My Seat that I got with the Dry Break CF tank also had a tab for pulling the seat bung, I have removed it - it was only made from race tape.

Edit round six 2008 GCC titled "DOUBLE WIN IN WHITE AND BLUE"