Greetings all,

I have a 1985 RS, my girlfriend has an '84 RS. Mine has a mild occasional steering wobble, hers has just developed a wobble severe enough to worry her and not ride it until fixed.

Some tedious googling revealed that people say "wobble" or "headshake" (or "head shake" or "head-shake") and these are the proposed solutions:

1. Steering head bearings loose/stuffed (oddly enough...)
2. Rear shock loose/stuffed
3. Front forks loose/stuffed
4. Either wheel out of true/round
5. Either tyre worn/flat, or just a brand characteristic (I have Bridgestone BT45s, she had Metzelers)

Has anyone else encountered this problem with a different cause? And are there any other symptoms we should look for which could help narrow down to a solution?

Much obliged,
Jonathan

Yep, mine does it. 60 kph, off throttle, loosen the grip on the bars...and boy, does it shake! If I took my hands right off the bars, it'd spit me onto the road in a flash.

My R100S did it, my R80 RT did it, but nothin' like my RS. I'm having a look at my steering head bearings soon.

Forgot to add...my PO had Metzelers and I now have BT45's.

I also know someone who had one new, and sold it after a nasty shake with luggage and wife on board. And on the other hand, we keep running into people who say "I had one of those - I did about 400,000km on it." One of them now has a Honda ST1300, which is a downgrade if ever I saw one.

I have seen a vague reference to some wheels being made with a not-quite-perfect axle alignment, but this is an onset, which means change, so I doubt that one.

J

Who fitted the tyres?
Tyres are marked with a rotation arrow and a spot circle. The spot should be set next to the valve to give the manufacturers balance and in normal riding I found this to be sufficient Balancing. I am a tourer and not a racer so the extra balancing is advised when very high speeds are used.
I have Avon as my first choice. ( Only on one bike) the rest all different and I have not experienced high speed wobble.
Head bearings are more noticeable on slow cornering.
As a thought , have you checked the oil level in the forks?
Ajays.

My K-RS occasionally gave me a fright, exiting corners at decreasing speeds only, with slight ripples in the road surface. The headshake was so bad I thought I was being talked to by a higher power...I took off the worn Bridgestone S11s (an ordinary tyre if ever there was one) and whacked on a set of Pirelli Sport Demons, and did nothing else. Now I am left to decide whether it's a 'higher' power talking to me. But the headshake's not returned.

I personally know few riders using a Canadian product call Dynabeads. They are 100% satisfied by this product and will never go back to weights. The next time that I will replace my front tire, I will try it too.
Last week, a friend just installed a new tire on her K75 and she was planning an 800-1000km ride for the week end. This is the first time that she uses the beads, and I will ask her if she found a difference.

Dyna beads are high-density ceramic beads that continuously balances the tires as you ride. The amount of material will distribute itself in weight and position dependent on the balance requirements of the individual tire.

You will need 2 oz of beads per tire. The cost for balancing 2 tires is $18.95

Check their Web site here

Hi Jonathon,
Have not checked if the RS has the same geometry as the RT but I have never ridden a bike with a more secure feel.
I am only running fairly ordinary Macadems but have stuck to the recommended size. I am not that fussy about tyre pressures either.
The worst I have felt is a "squirm" under unusual road surfaces but I have also been able to ride the bike albeit slowly with a flat front tyre for about 30k's

Ultimately I would be going through all the ideas you have including swing arm and wheel bearings and maybe even trying some higher bars as they will give you much more leverage.
One thing I did have although with no warning was a broken handlebar mount so definitely worth checking.

I think it's time to do a quick summary:

This appears to be a common issue (there may be a factor of these bikes being so precisely engineered that they're susceptible to minor problems, for all I know...), as I saw elsewhere.

Could be broken handlebar mount. Suppose so, worth checking.

Popular money is on tyres - both our tyre sets were new when bought - both had to be, to pass roadworthy - and I'm getting a new set in two days time. I have only randomly felt this, and more when the bike was new, so maybe something was settling in. Will be interesting to see what happens after my tyre person - who is fantastic - has put new rubber on.

My gf hasn't put many miles on her bike, so tyres still good, and it came on suddenly. Was fine earlier in the day on a quick highway run. Weight coming off rim, perhaps - unbalance?

Haven't ever checked fork oil in either bike or known when it was done - could be worth a look, I've already got the washers etc. to do a proper change for both bikes.

I've gone around her bike on the centrestand and pulled, twisted, wobbled and violently yanked everything with no sign of movement that doesn't seem normal and just like my bike, including the bars, and the tyres are perfectly seated at each end.

Oh, and - nothing wrong with her tyre pressures, or mine. In fact I know I've dipped 4psi in either end on a couple of times (800km weeks and always in a sleep-deprived hurry, was what that was) and haven't noticed any wobbles, just a sluggish touch in corners.

I'm going to ask to take hers for a run and see how it compares to mine, as a first step. And yes, I'll be careful.

I agree with Phil that it's incredibly secure (also a great bike for Tasmanian winters, particularly as RT) - the first decent run we went on together, we came to the top of a set of twisties and my gf described it as a cross between a Katana and a Moto Guzzi Sport. I'm still envious she got to ride that V11 Sport, years before we met.

If we come to anything definite, I'll report back, but neither of us has much time or money at the moment and it's not her only vehicle, so it could be a while!

Cheers all,
J

Mine had a `white line` wobble and also a wobble at 55-60mph, I replaced the steering head bearings, they looked ok but the grease had gone really hard-this helped still had the `white line` wobble but the 55-60 one was almost gone.

I swapped from pretty worn bt45`s to avons-this cured the wobble over white lines-personally I think its because we run skinny rims and crossply tyres, I have a wider rear waiting for the next payday to get the correct 160/60/18 on it and I think a 18x2.5 with a 110/80/18 radial will help.

The 55-60 wobble has almost been eradicated bythe latest bit of post winter fiddling, I put new pads in and replaced the pins with stainless, the wobble is stlll there but I will take one or both hands off of the bars and not worry.

Hope this helps

Ray

A theory :

• I've experienced this once at a particular speed when I took my hands off ... I also tried to reproduce it at higher and lower speed but couldn't

• I can't feel any shake or wobble at any speed when I have my hands on the handlebars, even if i use only two fingers to hold the throttle

My thought are:

• Our bikes have a vibration induced by the motor at around 3000-4000 rpm

• the extent of vibrations is varied but probably related to how well the motor is running

It is possible that the wobble is due to these vibrations. In science these are called positive interference. When two vibrations are generated at the same time they add and produce a larger wave. We all know about army marching over a bridge... if they are in step they can cause large vibrations. These vibrations resonate and peak and will also disappear depending on the frequency (rpm) and randomness (being out of step).

I don't know how to prove this, but if you:
have vibrations at a certain speed (rpm), see if you have it above and below (say 20km/h above and below). If yes, then you have a mechanical problem, if not, it is induced by the vibration frequency, almost certainly the motor + tyre + speed??

Just a thought, but it is possible.

Jonathon you are spot on regarding the RT and winter riding and I can empathise with the lack of finances and keeping these bikes on the road as motorcycling can never be called cheap and then add the age of the bikes and it all becomes compounded.

As for the broken handlebar mount it is either broken or not and when it is, the handlebars are free to swivel on the other one so in short you will notice it but if they were starting to go??

There are a lot of variables in this equation and it may just be a case of eliminating them one at a time but the testing phase is what worries me.
I can tell you my front rim was not the roundest until it was repaired and the back is not too flash in that regard.
So keep us informed and be careful.

"I have a wider rear waiting for the next payday to get the correct 160/60/18 on it and I think a 18x2.5 with a 110/80/18 radial will help."

Ray would you care to expand on that?

If you have an older K-100 how do you plan on fitting that rear rim & tire?

Thanks,
Rick

When you check your GF's bike did you get her to sit on the back seat on the centre stand so as to lift the front wheel off the ground, if you are looking for any trace of binding in turning the bars side to side you need to get the weight off the tyre to feel it.
Regards,
K-BIKE

Ned,
You are correct about engine induced vibration on the 100's (not so on the 75's because of the balance shaft.) I have no wobble up to 100mph... beyond I don't know..I chicken out..! Old age I guess. I just make sure I ride above or below 60mph when slight vibration comes in.
My bet is still tyres.
I like the sound of beads introduced into the tyre when fitting new, I'll try that on my next set. First I have heard of them.
Ajays
Bike courier services love the RT's very popular here.

Finally_A_K wrote:"I have a wider rear waiting for the next payday to get the correct 160/60/18 on it and I think a 18x2.5 with a 110/80/18 radial will help."

Ray would you care to expand on that?

If you have an older K-100 how do you plan on fitting that rear rim & tire?

Thanks,
Rick

Personally I think our old kay`s are under tyred and modern radials wear and grip much better than skinny crossplys and way bmw`s are built quite a few diffrent wheels will fit diffrent bikes, I have a R1100rs rear wheel (18x4.5 takes a 160/60/18) in the garage ready to be fitted, There may be issues with the centerstand fouling the wider tyre but a k1100 stand should sort that out.

on the front you have a choice of 18x2.5`s k75s had one and you can use your original discs, k1100lt is the other option but it has 305mm discs so you would need to have your calipers spaced out, this allows a 110/80/18 radial to be fitted.

Dont hold your breath though, I have had the wheel since midwinter and still have my tyre money stolen each month!!! kids huh!

Ray

Hi there.
I had (hope) the near 60KPH wobble, so I could not leave the bar and "hip turn" the bike, and another wen going near 160KPH
So the rims were sent o check and align, tires changed and balanced.
As result the 160KPH one got cured, but the low speed one did not.
Talking to a friend he sugested to check de rear shock bolts. Those were not full thigth, once they were at spec torque the wobble dissapeared.
Now I can even stand up hands free
Best regards
JAP

Ray, I am encouraged by you're optimism, but that 160mm rear tire and 4.5" rear wheel will be difficult to install.
I just installed a fresh set of Avon radial tires on my 1985 K-100RT.
I installed a 110/80zr-18 front, and a 140/80zr-17 rear.
The rear tire just fit, it cleared the swingarm by 1/8", the stand was close too but not an issue.
The front was tight and required trimming down to the minimum the fender mounting bolts.

If you do fit up that bigger rear I would really like to be in that loop!
BTW that Avon tire combo was an AV55 front & a AV46 rear.
It went down the road like a dart...no shimmy, no shake, handles the radials like it was built for them.
Thanks,
Rick

http://www.bmbikes.org.uk/Forum/viewtopic.php?f=13&t=10607
you may have to regester to view the pics on this post.

I just sold a 3 spoke 17x 5.5 which would have taken a 180/55, not that would have had clearence issues!.

also Finally_A_K what rim have you on the front?

Ray

Ray, I checked out those 3 pics....I see the guy mounted the wheels, but like he said (I think) the rear wheel will be off-set from the front one, not in the same track line.
Is that right, or am I all screwed-up?
I just cannot see how center-line of the bike will be respected with a 4.5" rear....
Anybody else here done this?

As for my front wheel it is a stock skinny-minny 2.5" x 18"

Rick

Hi Ray,

I recently fitted a K1100 centrestand and I have a 130 tyre on the back. Any bigger and you may have some issues.
There is a fair bit of meat on the stand so could be ground off but I doubt if it will be a straight fit.

Ray, if I understand you correctly, you are thinking to fit 160 tyre on what is considered to be 140 max rear.

I just went through the process of fitting a new radial and I can tell you that 140 is the max I would entertain. It is almost certain that 150 will rub against the shaft hosing and 160 will not fit.

If I was really brave I could take a grinder to the shaft hosing and remove a few mm of casting ridge but that would be risky.

The radial that fits is Avon Azaro and if you can get them, Dunlop 2?? (205 I think). Many cross plays are available.

However if you manage to do it without changing hardware, I would be interested to know.

Ajays wrote:Ned,
You are correct about engine induced vibration on the 100's ...

...I like the sound of beads introduced into the tyre when fitting new, I'll try that on my next set. First I have heard of them.
Ajays....

Well it was a shot in the dark. Thinking about it, I say that if the vibrations have anything to do with it, it is minor and possibly only to initiate the wobble.
My experience was that the bike was pointing down hill at around the speed suggested ... i took my hands off to adjust my helmet or some such and got a shock on my life. I can't understand why I couldn't feel anything through the handlebars ? Strange.

beads? any links?

maybe this will help:

http://www.randakks.com/TechTip87.htm

Looks like some good info although I am a little dubious about the three pound counterweight.

Sounds like a problem they could not fix and as luck would have it bunging a weight there and calling it a junction box did the trick.

Ned,
Try this. http://www.dynabeads.co.uk/autobike.php
Ajays

My K100 RS 16 Valve has never shown a hint of wobble at any speed one hand or two even with as Ned says just two fingers holding the throttle open.
Regards,
K-BIKE

I just cannot see how center-line of the bike will be respected with a 4.5" rear....
Anybody else here done this?



Rick[/quote]

It appears that bmw Kay`s have always had a offset centerline through the wheels, I will addposts later(just started a night shift-boo!)

Ray

Ray, I'll look into that bit....
Easy enough to do, a builders square and a chaulk line will tell the tale.

I'll post my obsevations.

Rick

Hi Jonathon
I'd like to add road surface to your list if I may
I've had the odd wobble due to an uneven road surface and maybe councils
are skint nowadays but the roads seem to be in pretty poor shape round here.

I know its an obvious point but Ive been caught out by a few hard to spot sunken sections and channels
that caught me unawares and had me gripping the bars nervously.
Otherwise I've found my K to be a very stable machine and rarely have to hang on grimly.

Yesterday riding on some quiet country roads with good surfaces I made some cautious experiments
and I found I could let go the bars whilst decellerating at speeds from 40 to 80 mph.
Bog standard, well used, BT45's fore and aft.

I hope you find and fix the problem with your gf's bike
Its unnerving to have a bike start wobbling under you and I wouldnt want to ride
one that did that either.

Reg

I cured wobbling problem with new front tyre. Its old model Dunlop Arrowmax GT 501, now I am driving second front. First was 110, next 100, no wobble at all at any speed. Suspension on my bike is original from 1983.

Cheers

Hi Nino
glad to hear you fixed the problem, I had similar with Metzler Lazertec front tyre, thought it was normal to wobble on uneven roads then put on Pirelli Sports Demons and problem wnet away.
Happier riding mate
RT

Worst wobble was with Avon azzaro 45 on the front (at cca 80 kmh). I never tried Demon (incredibly expensive here), but much cheaper Arrowmax was absolutely wobble free at any speed.

Regards

I'm curious about some of the outcomes on this thread. Today I noticed for the first time a severe wobble consistently from 80-60 kph off throttle. I'm using pirelli sportdemons front and rear. I will check the balance but has anybody done follow up reports on the beads as a solution?

wow 88 thats strange what was the front presure ?

i had a similar issue one time ...off throttle and let go of the bars ...big harmonic wobble ....

later we (alby ) relocated the forks heights with the bounce method to set up the front suspension again ..havent noticed the same since

Charlie, Front pressure was down about 3psi when I first picked it up so I pulled in and reinflated to correct psi, fore and aft. It was still there after and I tried it on various road surfaces - I reckon it is somewhat of a harmonic vibration. Off the throtte you can't stop it above 60kph but once you get below it a light toutch stops the wobble and it doesn't resume. I will have to wait until I'm stripping the front end for other works in a couple of weeks to look at the forks, meanwhile I will keep a good grip on the bars.

hmm steering head bearings ...notched ?

Over the years I've made a few observations about steering wobble:

Tyres are crucial. I love BT45s and Pirelli SportDemons, but wouldn't be prepared to trust anything else. YMMV, and best of luck to your own research.

Headset bearings are crucial - obviously. When this started, mine were shot but replacing them was only half the problem because I had a good but completely wrong tyre. My GFs bike had bearings fine but pressure wrong and here tyres were good but not ideal for the bike.

Tyre pressure is crucial: The back getting low just results in some sluggishness into corners, but the front getting low can induce shake and a feeling of the bike falling into the corner. The rear being too high makes the bike nervous, the front being too high makes it skittish and susceptible to shake. These days, I check the pressures but usually go on how the bike feels.

Tyre wear is crucial: The worst head-shake I have ever felt was the last tyre, when I let the front get too worn. There was adequate tread all the way around, but it was the wrong shape - the sides had flattened off quite noticeably so the sides were getting to the wear marks while the middle was still only halfway down, and that vibrated at all times, at all speeds. It happened during the busiest fortnight of my life, so finding time to get it changed became a nightmare.

The beads I have not tried and frankly distrust. They may work, but I would prefer to make sure the wheel is good and balanced and the tyre is good and on correctly.

[quote="Finally_A_K"]Ray, I checked out those 3 pics....I see the guy mounted the wheels, but like he said (I think) the rear wheel will be off-set from the front one, not in the same track line.
Is that right, or am I all screwed-up?
I just cannot see how center-line of the bike will be respected with a 4.5" rear....
Anybody else here done this?

As for my front wheel it is a stock skinny-minny 2.5" x 18"

Rick[/quote]

Guess what? On a paralever K100 16V or K1100RS, the centerline of the rear tire is offset to the left of the front tire by a good 25 mm. Think about it, the geometry and dimensions of the frame, engine, engine output shaft, transmission input and output shafts, drive shaft and mounting flange for the rear wheel are the same relative to the centerline of the bike for all of the Ks except the K1200. So when you have a K100 16V or a K1100RS (but less so on the LT due to it's narrower rear wheel) with their wider rear tires, this offsets the centerline to the left.
It's ok too. In fact it is beneficial, aiding straight line stability at higher speeds. A friend of mine deliberately offsets rear wheels of his BMW customs for exactly this reason, and I have done it, but to the right (opposite the final drive) on a Harley Street Rod when i fitted the bike with wheels from the XR-1200 and it works. Read the V-Rod forums, all the whining about bikes pulling to the right. Mine does not, nor does my Paralever conversion 1984 K100RS shown in my avatar.

Ok, check the head bearings first. Put the bike on the center stand and use a jack under the engine to lift the front tire off the ground. Rest your hand on top of the front fender. Turn the steering slowly either side of center. If you feel a notch as you pass center, the head bearings need to be replaced. Ok, do this slowly and patiently. If there is a notched race, you will feel it.
If the bearings are good, make sure they are pre-loaded correctly. Harley Davidson has a surprisingly fool proof way to check this. They call it setting the "fall away". Here is why. Center the front wheel. Put a chair or something right at the front tire. Measure how far to the right and left you can ease the front tire from centerline before it falls all the way to full lock on it's own. Correctly set, there should be enough head bearing tension for you to be able to displace the front tire no less than 50 mm and no more than 100 mm from center before it falls to full lock on it's own. If the bearing preload is too loose or too tight, adjust accordingly.
Of course tire pressure and tire wear are factors in these wobbles and weaves too. But old K bikes have a fatal flaw that can lead to scary weaves and wobbles. The stock steering geometry lacks trail, which stabilizes the bike. They also have exceedingly soft suspensions. If you are carrying a heavy touring load and/or have the bike leaned over in a fast corner, the stock fork springs can compress enough for the bike to run out of trail and become unstable. Combined with a soft rear shock, you can get enough forward pitch in some riding situations to develop a very scary high speed weave.
Quality suspension at both ends can mask the problem to a degree by eliminating the gross changes in suspension geometry that can get you into that danger zone when all your trail is eaten up. Make sure you have good fork springs that are not sacked (lost length from age and use), likewise have a good functioning rear shock and I have a preference for Avon radials for the old Ks with skinny wheels. You can use a 110/80ZR18 Storm ST front and 140/80ZR17 Azaro rear. These work better than any bias ply tire and last longer, making the cost per mile very competitive with "cheaper" bias ply tires. Lets put it this way, on Michelin Macadams I would slide the rear tire of an otherwise stock K before touching a peg to the pavement. On the Storm ST/Azaro combo I could deck the pegs, fold them against the foot peg plates and the bike was not even a little loose, and I would still have a tiny chicken strip left on the wee edge of the tire. Straight line stability is superb and you can howl the front tire before it locks under hard braking. Hard not to like that.

Themason wrote:
Guess what? On a paralever K100 16V or K1100RS, the centerline of the rear tire is offset to the left of the front tire by a good 25 mm. Think about it, the geometry and dimensions of the frame, engine, engine output shaft, transmission input and output shafts, drive shaft and mounting flange for the rear wheel are the same relative to the centerline of the bike for all of the Ks except the K1200. So when you have a K100 16V or a K1100RS (but less so on the LT due to it's narrower rear wheel) with their wider rear tires, this offsets the centerline to the left.
It's ok too. In fact it is beneficial, aiding straight line stability at higher speeds. A friend of mine deliberately offsets rear wheels of his BMW customs for exactly this reason, and I have done it, but to the right (opposite the final drive) on a Harley Street Rod when i fitted the bike with wheels from the XR-1200 and it works. Read the V-Rod forums, all the whining about bikes pulling to the right. Mine does not, nor does my Paralever conversion 1984 K100RS shown in my avatar.

I have just measured a K1100 RS that just left my workshop and measured my K1100 LT which has K1100 RS wheels front and back. There is no offset at all both were exactly centre. So GUESS WHAT I am calling you on that.
Documented source from Factory or it's BS, I have never heard such a load of it in all my life.

Is the face of the wheel hub centred or off-set on the different width wheels?

The paralever has a different ofset to the mono lever. The face of the hub on a paralever is 14mm futher right than the mono, it was done to make room for the 4.5 inch wide wheel that the K100 16v and K1100RS 16v has. The K1100 LT has a 3in rim but the same ofset as the 4.5in wheel so it remains in centre. Some of the guys have put a 4.5 in wheel into the K100 monolever but it ends up 14mm to the left and the centre stand has to be modified to accomodate this. With radial tyres there doesn't seem to be too much pulling either way. I have yet to ride one and reserve my decision on the wisdom.

Rick G wrote:The paralever has a different ofset to the mono lever. The face of the hub on a paralever is 14mm futher right than the mono, it was done to make room for the 4.5 inch wide wheel that the K100 16v and K1100RS 16v has. The K1100 LT has a 3in rim but the same ofset as the 4.5in wheel so it remains in centre. Some of the guys have put a 4.5 in wheel into the K100 monolever but it ends up 14mm to the left and the centre stand has to be modified to accomodate this. With radial tyres there doesn't seem to be too much pulling either way. I have yet to ride one and reserve my decision on the wisdom.

Is the face of the rear wheel in the centre or off-set?

The K100 rear has the face of the hub to the left of centre. The 3 spoke K1100 LT is not quite so offset, it could be centre but I am not sure, I have one here but it's dark and mozzies abound so I won't be going out to the workshop till morning and I will measure it then.

you will find the distance between the swingarm and the tire to be the same distance with either of the 2.75-3 or 4.5 inch wheels ....so assuming that, the drive side off set between hub and rim is the same ( what we measured some time ago ) the extra width on the rim on the three spoke rims is acheived on the centering of the spokes centreline towards the left hand side of the wheel ....so sometimes will also interfere with the muffler ...easilly fixed

additionally the k1100 centre stand (and i guess the 16 valve ) has a slight difference as it finnishes with a straight leg on the left hand side ...rather than the 2 valve spread of the support legs getting wider as the bend of the stand hits the road .

so with the paralever rear end it should clear ...(offset in addition to the 2 valve standard is further to the right to the hub ( from center line )) about 14 - 15 mm

so a little cutting of the foot of the 16 valve stand is required to clear the 4.5 inch rim and tyre on a standard 2 valve rear end clearly .

caferacer did a widening mod on mine and it worked well, yes sir ..(thanks mate )

hope that help some one

btw ...the fork braces could be a good thing (found on k75 c and others after 88? and k1100 ) if you are doing the big rear wheel modification to 160 mm radials

but make sure you have really good swing arm bearings and pins ...in any case

some pics here https://www.k100-forum.com/t2713p100-wider-wheels-radial-tyres-on-a-k100#35005

you will note the centre of the tyre in relation to the rear mudguard ...i measured it at about 15 mm in the pic from the rear

For what it's worth my 11/87 K100 tyre placard refers to 140 width radial tyres as an option on RS's but doesn't say what wheels they were fitted to.

they fit the standard rim basic ...ive got one on now

for some maufacturers tyre compound formulars have come a long way since the eightys

grinding pegs round corners in absolute control ....no worries

The wider rims which are 18 x 4.5 rear and 17 x 3 front didn't come out till the 16v K100RS in early 1989 and then were available on the K1100 RS but not the K1100 LT which had 17 x 3 rear and 18 x 2.5 front.
So the tyre info on an 87 bike wont make any mention of the wider wheels because they didn't exist except on maybe a few prototypes.

My source is a gentleman who built and tested the prototypes of the K bike. I can tell you this much. You can put 1984 transmission gears and shafts into a Paralever gearbox housing. I have done so. I didn't buy a whole Paralever gearbox for my Paralever conversion. My friend had a K-75 gearbox case with the Paralever mounting flange cast into it. He drilled that flange for the Paralever arm and he put my old gears and shafts into that case. That means, folks, that the geometry of the transmission input and output shafts of Monolever and Paralever gearboxes are identical, and it also means the drive shafts of Monolever and Paralever bikes are offset from the bike's centerline the same amount. If you compare Monolever and Paralever rear wheels, the degree to which the 4.5 inch wheel is offset to the left of the mounting flange is obvious. Monolever or Paralever, the right edge of the tire rides just as close to the swingarm, so the extra width comes by offsetting the tire centerline left.

My friend from BMW Research tells me BMW now does this deliberately because it aids straight line stability. He would know because he built them! He now builds bikes this way for customers, even having spoke rear wheels on old airhead twins laced with an offset to the left. I did much the same on a Harley Street Rod, offsetting the rear wheel to the right because the final drive pulley is on the left and exhaust is on the right, the opposite of the K bike, and like my Paralever conversion K, it now tracks dead straight. On the Street Rod I did this more to stuff a different wheel and rear pulley into the stock swing arm, but the effect on straight line stability was immediately apparent.

I can also tell you that on my Paralever conversion K bike the rear wheel is very much offset to the left. I first noticed this offset working on a customer K1100 when I was making money as a part time tech. I thought something was wrong with the bike but my friend from BMW Research told me that this was normal for those bikes, and that is when he explained the desirability of this feature.

Hi, has the original poster checked the swing arm for slack in the bearings?