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TECHNICAL MOTOBRICK WRENCHING In Remembrance of Inge K. => The Motobrick Workshop => Topic started by: TaosBrick on May 17, 2016, 01:39:14 PM

Title: Bike goes to the right when ya let go of the bars...
Post by: TaosBrick on May 17, 2016, 01:39:14 PM
...and yet, you have to hold the bars ever so slightly Pushed To The Right to keep it tracking straight.
Have loosened everything on the forks and top clamp and tightened it back up while holding it all skewed one way, took a ride up street and back - no change. Loosened everything up, then tightened it back up skewed the Other Way, STILL no change  :dunno2:
Wondering if swingarm is cocked somehow, or frame bent? Am on road right now and do not have a level or any other tools to figure this out, as if there's anything I can do about it now anyway.
But gotts to tell ya, after a 600 mile day of holding the bars with that even that teensy bit of pushing to the right, one gets a bit tired, stiff and annoyed.
Any tips welcome, Fellow Bricksters!
Title: Re: Bike goes to the right when ya let go of the bars...
Post by: tsnap on May 17, 2016, 02:19:56 PM
check tires for uneven wear.  Most riders are more aggressive in a turn in right or left direction, depending on the rider.  Is this a new bike to you?

Fork tubes pushed all the way up?  Did you have the tubes out?  Axle needs to be in place when tubes are reinserted in triple clamp.
 (just watched the chris harris bearing change, laughed thru the whole thing!!

https://www.youtube.com/watch?v=UJr8oYp9rJ0)

A dragging caliper or dirt in caliper/pad?

Is it a windy day?  Wind out of the left?

It turns to RIGHT when bars released at speed. then....you have to PUSH right  side bar (pull left side bar) to keep it straight?  All at speeds OVER about 10 MPH? (gyro effect)

tom
Title: Re: Bike goes to the right when ya let go of the bars...
Post by: tsnap on May 17, 2016, 02:25:47 PM
Is the steering "notchy"?

Did you give the front wheel a good front to rear shake to test head bearings? Possible broke bearing or race?

Which bike is this?

tom
Title: Re: Bike goes to the right when ya let go of the bars...
Post by: TaosBrick on May 17, 2016, 02:53:38 PM
Thanks Tom. So... Nekkid K75, 1992. EVERYTHING in the front end was either replaced or lubed before my trip from Taos to Nashville. New fork seals, wheel bearings, steering head bearings cleaned and lubed - both roller cages fine, bottom race fine, top race Ever so slightly worn/scalloped, but when re-assembled and torqued to spec, no notch-eyness detectable with the front wheel held up off the shop floor and turned from stop to stop. No draggy brake pads either. Bike goes right at whatever speed or wind direction.
  Note: this issue existed Before I did the front end R&R, and has to some extent since buying the bike in 2011. For whatever reason, it seems to be a bit more noticeable at present. Rear tyre IS worn out, due to be replaced Thursday. Will be interesting to see if that has any effect.
When I bought the bike, the right handle bar was tweeked a bit, bent it back straight.
PO said that this had been the result of a 'garage drop'. In light of what's going on, I am suspecting he actually took a bit of a digger and may have fibbed about it.
Title: Re: Bike goes to the right when ya let go of the bars...
Post by: TrueAce on May 18, 2016, 12:47:39 AM
I am suspecting the rear wheel is not aligned properly, causing the front to behave as described............the worn rear tire could be a factor, also check for the spacer when mounting the new tire against the off-chance it isn't there, check the shock mounting bolts for any play. Let us know how it performs after the new tire. One other possibility, make sure triple tree bolts and axle bolts are proper torque. I once experienced a "dancing" front pull and discovered the above bolts had not be equally torqued after a complete front end rebuild. Also have noticed handling quirks when fork tubes are off dead even by just a slight amount. Final grasp......are the fork oil amounts equal?
Title: Re: Bike goes to the right when ya let go of the bars...
Post by: tsnap on May 18, 2016, 02:00:53 AM
incorrect fork tube fluid filling. unequal springs, missing parts, spacers, bushings, dust caps.

correct front wheel spacers on front axle. I believe the left and right are 2 different sizes. That is seen in the above video on disassembly.

that upper race showing wear worries me.  It is magnified by the length of the fork tubes.

Were the fork tubes checked for straight and true and round?. I have seen them bent on bikes  following hitting a curb or severe pothole,  or rear end collision. Symptom is a leaking fork seal due to "out of round".

check rear wheel for bends when tire is off.

check shock bolts and bushings, shake and lever with pressure for play.

Inspect lug nutz and mating surfaces for flatness and complete correct nut seating.

check tracking before and after new rear tire by pushing bike across a nice smooth garage floor after wetting tires with spray from water or windex bottle, or by sprinkling flour on floor and pushing bike across it in vertical position, note tire track print.

the human always wins these battles.

tom
Title: Re: Bike goes to the right when ya let go of the bars...
Post by: TrueAce on May 18, 2016, 02:55:59 AM
+1 what Tom said! It ain't right, but you'll figure it out.
Title: Re: Bike goes to the right when ya let go of the bars...
Post by: tsnap on May 18, 2016, 05:57:33 AM
maybe that;s why my earlier post disappeared?  I thought I posted it somewhere else or failed to push the  button.  Hope I didn't send you on a wild goose chase!! :dunno2:

tom
Title: Re: Bike goes to the right when ya let go of the bars...
Post by: johnny on May 18, 2016, 06:30:21 AM
greetings tb...

is this chili red...

wanna make sure i understand...

riding on good flat road you have to keep forward pressure on the right grip or the moto will slowly angle right...

is this correct... there is a relationship between countersteering and offtracking... happens in an instant...

considering no wind and your cargo weight is even on both sides and you dont have any bagpipes acting as a sail... when you let go of the bars does it angle left or angle right...



j o
Title: Re: Bike goes to the right when ya let go of the bars...
Post by: Scott_ on May 18, 2016, 06:58:42 AM
Have you noticed it behaving the same way in both lanes?
Road crown can/will have an effect.
Tire balance can also throw you off as well.
By factory specs, the front/rear wheels are offset by about 1/2", so keep that in mind if you do the "roll thru water on a flat surface" or try to check them with a string line.
Title: Re: Bike goes to the right when ya let go of the bars...
Post by: Laitch on May 18, 2016, 08:04:23 AM
. . . and you dont have any bagpipes acting as a sail...
So that's what was causing my difficulties. I've put them on Craigslist to swap for a saxophone.
Title: Re: Bike goes to the right when ya let go of the bars...
Post by: TaosBrick on May 19, 2016, 08:25:33 AM
Ok, getting new rear tyre today.
In answer to queries, bike starts going right immediately upon lettin' go the bars - on both sides of the road.
Forks internals were cleaned spotless, then the Exact Same volume of oil filled in each side (you 'measure levels' people can sputter as much as you like).
Yes, the spacer should be there, was last time I had that rear off. Rear tyre wear on right side is interesting tho. I have seen lots of rears that were worn on the left, due to road crown.
Defective tyre? Some other radically wrong thing with frame-swingarm alignment?
I DID put a used transmission on the Beest shortly after mounting the current rear. Something with swingarm pivot pins? But that is a fixed, unchanging commodity in Brick-dom, far as I understand. Swingarm Pivot bearings seemed fine.
Also, spun the fork tubes around in the clamps to several different positions - all subsequent test rides showed no change. Each time everything below the top clamp nut was tightened First after using bounce method of fork alignment.
Title: Re: Bike goes to the right when ya let go of the bars...
Post by: johnny on May 19, 2016, 08:38:27 AM
frame shims can cause this... didnt think about it until you mentioned trans swap...
Title: Re: Bike goes to the right when ya let go of the bars...
Post by: TaosBrick on May 19, 2016, 08:43:31 AM
Frame shims - where is they? On swingarm pivot mounts? Didn't notice any shims when I had the swingarm off the frame, but that was over a year and a half ago, and at 57 I am beginning to notice the effects of half-hiemers.
Title: Re: Bike goes to the right when ya let go of the bars...
Post by: tsnap on May 19, 2016, 08:56:50 AM
I just due dilled frame shims search and found this thread x2.

tom
Title: Re: Bike goes to the right when ya let go of the bars...
Post by: Scott_ on May 19, 2016, 01:20:45 PM
Yea, if you are having wear pattern on the right side of the rear tire, you have something out of whack.
The frame shims mentioned are used with the motor mounts. Look up the frame to motor mount instructions for a better explanation.
Makes me wonder if something was tweaked, as you say it had been dropped hard or hit.
Title: Re: Bike goes to the right when ya let go of the bars...
Post by: tsnap on May 19, 2016, 05:05:03 PM
hue said prev owner admitted to a garage fall over type incident

tom
Title: Re: Bike goes to the right when ya let go of the bars...
Post by: TaosBrick on May 20, 2016, 11:45:08 AM
Update - New rear tyre installed. Situation improved somewhat, bike does not go as hard to the right when bars let go, but still enough to be annoying. Closer examination of the old tyre shows right side noticeably more worn, with a bit of cupping on the left.
  With everything on the front end being rigorously examined and repeatedly adjusted and Both wheels balanced, it would seem that a tweeked frame is the winner in this diagnosis party (and I am the loser).
The question now is will frame shimming be enough to solve this, and how does one determine which side to shim, and how much? I guessed that the two rear transmission mounts are where this is to be done, but the fiche points to the Front engine mounts as to their location.  :dunno2: Ah, geometry. I was fairly good at it in school, but in this application I am not so sure...
Title: Re: Bike goes to the right when ya let go of the bars...
Post by: TrueAce on May 20, 2016, 02:35:00 PM
Could the tire wear and poor handling be due to a bad rear shock?
Title: Re: Bike goes to the right when ya let go of the bars...
Post by: The Dude on May 20, 2016, 03:28:47 PM
Update -:dunno2: Ah, geometry. I was fairly good at it in school, but in this application I am not so sure...
Are you one that rides with their arse hanging off the side of the seat?(they often don't know)
Or to put it another way,have you tried riding with your arse hanging off the seat and does this help?
Ok, mine (brick)does a little of this so I just whack it back with my knee and carry on texting. :neener:
Yours must be real bad?
Title: Re: Bike goes to the right when ya let go of the bars...
Post by: TaosBrick on May 20, 2016, 06:14:09 PM
Could the tire wear and poor handling be due to a bad rear shock?

Don't think so. Shock seems fine. This bike was "dropped" by movers according to the PO when moving from Philly to Santa Fe, where I purchased the bike. I am beginning to think it must've been dropped from the back of a large, tall moving van. When I got the bike it was barely noticeable. But after having replaced the transmission, it became more noticeable and the funky tyre wear began.
  The reason I'd replaced the trans was failure of input splines - within 20k miles of them being lubed. Perhaps another suspicion from something bring majorly outta whack.
Have gone only 8k miles since replacing tranny, almost feel like having a look at those splines when I get to 10 or 15k to see if inordinate or weird wear is happening...
Title: Re: Bike goes to the right when ya let go of the bars...
Post by: TrueAce on May 20, 2016, 06:48:03 PM
Dropped? Enough to bend that drive train a tad causing spline & transmission failure............not good. We call that Broke Back Syndrome. Could the transmission be slightly misaligned? Having never replaced a transmission, I am not familiar. Bet Mighty Gyphon could advise, among others. Seem there should be evidence in measuring the frame which would reflect a drop impact of that magnitude. Is the rear wheel totally straight & undeformed? The right side tire wear and left side cupping suggests something is wobbling somewhere on the back end.
Title: Re: Bike goes to the right when ya let go of the bars...
Post by: tsnap on May 20, 2016, 07:06:32 PM
iF A CARRIER DROPPED IT, HE MAY HAVE SETTLED FOR A CASH SETTLEMENT.

mAYBE A carfax would reveal something?

tom
Title: Re: Bike goes to the right when ya let go of the bars...
Post by: TaosBrick on May 20, 2016, 10:09:25 PM
Another couple of things to ponder - the input shaft splines on the original trans had failed once before, at something over 10k miles, if my memory of this occurrence in the meticulously kept shop records that came with the bike is correct. Original owner had the input shaft replaced. I had acquired it at 28k and am the 3rd owner.
   When I did my first spline lube, at something like 35k, the transmission was a Total Bugger to stab, took over an hour and the help of another pair of hands to finally get the shaft into the clutch - and I'd not done a thing with the clutch.
  In contrast, when I stuffed the new/used trans, it went in like butter. Weird, no?
Title: Re: Bike goes to the right when ya let go of the bars...
Post by: The Dude on May 20, 2016, 10:45:35 PM

  In contrast, when I stuffed the new/used trans, it went in like butter. Weird, no?
Yeh.Weird.I thought it was just Moto Guzzi that made lemons!least "going in like butter"indicates you won't find any spline wear issues after you're short mileage.
Surely, this can't be where your tracking problems originate?Accurate wheel alignment measuring?bent frame?should all be obvious,by now.
That top stearing head bearing cone,did you take it out then put it back in,(slightly rotated) to clean it?yeh,long shot!I would have left it in...
Title: Re: Bike goes to the right when ya let go of the bars...
Post by: Scott_ on May 21, 2016, 08:40:36 AM
I can't remember who, rbm or inge, or the context of the discussion, but non the less, the discussion was about faulty/out of spec, intermediate housings.

Title: Re: Bike goes to the right when ya let go of the bars...
Post by: The Mighty Gryphon on May 21, 2016, 09:19:07 AM
Can't add much to this discussion.  Everybody has covered everything I could think of plus a lot more. 

As far as engine shimming, here is the factory scoop on bolting the frame to the engine.  Download and go to page 144 0f 461.

http://www.k100.biz/pdf/OFF/K100_K75_2V_eng.pdf

Title: Re: Bike goes to the right when ya let go of the bars...
Post by: Laitch on May 21, 2016, 09:59:01 AM
. . .  but non the less, the discussion was about faulty/out of spec, intermediate housings.
The discussion I recall with that condition cited was about premature input shaft spline failure. During one of my loiterings, I found a service bulletin in MOTOBRICK.COM's link to Vogel's service bulletin compilation. It indicated that positioning dowels were located on each side of the intermediate housing to correctly align the engine with the transmission. The implication was that if they were missing, trouble would follow. I didn't associate misalignment with tracking problems but rather with shaft spline failure. There might be other effects, too.
Title: Re: Bike goes to the right when ya let go of the bars...
Post by: tsnap on May 21, 2016, 10:33:26 AM
Yesterday I finished work on a bike (85 Hondu 750 cruiser shafty) that had been dropped on its Right  side, a slide from the looks of it.

Scraped case, mirror, stand, exhaust, tach, and plastic windshield gone with brackets remaining..  I test rode it, and it had no pull to a side, but the pullbacks were  barely noticeably lower on the Right  side when sitting on it.

 I once rode a goldwink that showed no damage anywhere, other than the front fairing was gone, but it pulled to the right constantly, almost impossible to make a short turn.

METAL HAS MEMORY.    I suspect that a part of the thread topic bike has been tweaked beyond tolerance for the metal part and is  bent, appears OK,  and failure shows up only under the stress of normal use. I suspect that it is a part in the fork.  May be a result of being dropped on its head.(not the brick head itself, but the other head)

tom (keyworts search button, donkey, techron, can you reed, no facebroke,etc)

Title: Re: Bike goes to the right when ya let go of the bars...
Post by: rbm on May 21, 2016, 04:49:34 PM
Deleted.  See Gryphon's post above.
Title: Re: Bike goes to the right when ya let go of the bars...
Post by: The Mighty Gryphon on May 21, 2016, 06:29:12 PM
Rob, is the link I posted not working?  It is in English and pretty straightforward.  I used it when I put the frame back on my 75RT last winter and it worked the treat.
Title: Re: Bike goes to the right when ya let go of the bars...
Post by: rbm on May 21, 2016, 06:40:32 PM
Sorry Gryphon.  It is working.  I was negligent in glossing over your post.
Title: Re: Bike goes to the right when ya let go of the bars...
Post by: The Mighty Gryphon on May 22, 2016, 09:31:34 AM
No problem, Rob.  I wasn't sure if it would open properly since it is a PDF file and I never posted one of those before.

BTW, I have to get up to the GTA to deliver some coffee to Ed.   Weather is nice enough now to justify a brickoliscious ride. 
Title: Re: Bike goes to the right when ya let go of the bars...
Post by: bocutter Ed on May 22, 2016, 11:30:42 AM
BTW, I have to get up to the GTA to deliver some coffee to Ed.   Weather is nice enough now to justify a brickoliscious ride.
Figured that coffee would have been consumed by now.  :hehehe
Title: Re: Bike goes to the right when ya let go of the bars...
Post by: The Mighty Gryphon on May 22, 2016, 11:56:05 AM
Still hanging on to it.  Got to get a chance to visit for more F&C.  trouble is I am pretty busy working 7 days a week now. Busy part of the sailing season.  Should calm down in a week or so.
Title: Re: Bike goes to the right when ya let go of the bars...
Post by: bocutter Ed on May 22, 2016, 08:18:42 PM
Still hanging on to it.
Damn man, crack one open. I have an espresso machine at home (use vac pak) and you've sampled the fresh ground at the shop. I might use one or two packs of that coffee summer camping. The rest will be Xmas presents ... I really just want the cans for Bwokx staple containers.  :lets-eat:
Title: Re: Bike goes to the right when ya let go of the bars...
Post by: johnny on May 22, 2016, 09:42:47 PM
look... as i understand it...

flat straight road... let go of the bars and the moto angles right... and its pushing the right bar forward that makes it go straight again...

when i push my right bar forward my moto will go to the right...

when i push my left bar forward my moto will go to the left...

taos here is pushing his right bar forward and his moto is going left...

countersteering can only be achieved after the tiors contact patch has started to lean... even minuscule...

what taos is describing could be one fork lower than the other... whack frame... whack engine to transmission alignment... whack swing arm... or simply the rear ride height too low which is initiating what is known as castoring or bicycling...

j o

 
Title: Re: Bike goes to the right when ya let go of the bars...
Post by: The Dude on May 22, 2016, 10:01:01 PM
What are the rotating and counter rotating lumps in the motor & transmission doing when he lets go of the throttle?
Title: Re: Bike goes to the right when ya let go of the bars...
Post by: Martin on May 22, 2016, 10:22:51 PM
This is a bit of a long shot, do you have anybody close by with a K75. If so you can possibly compare measurements with it to see if anything is out of alignment. Alternatively can you get the alignment measurements off a dealer.
Regards Martin.
Title: Re: Bike goes to the right when ya let go of the bars...
Post by: kennybobby on May 22, 2016, 10:36:41 PM
It's called "toe displacement" in the manual, and for some stupid reason bmw designed these bikes to have the rear wheel offset to the left of the front, which makes the bike pull to the right and wear a flat patch into the left side of your front tires--the shims between the frame and engine can only increase this offset and make it worse.  Cussed and discussed here:

focked up suspension design (http://www.motobrick.com/index.php/topic,1373.msg6349.html#msg6349)
Title: Re: Bike goes to the right when ya let go of the bars...
Post by: johnny on May 23, 2016, 05:49:45 AM
taosbrick is reporting when he pushes the right grip forward the moto goes left...
Title: Re: Bike goes to the right when ya let go of the bars...
Post by: The Dude on May 23, 2016, 07:16:56 AM
taosbrick is reporting when he pushes the right grip forward the moto goes left...
Now that's not right er I mean correct.We all know what the Moto as you call them does when you do that.
Front wheel goes to the left causing the Moto to fall to the right.If you don't wack open the throttle or counter steer it's horizontal.Fast.  :falldown:I couldn't see any side car in the story....so.
Now,there's all the engine mass,transmission heavy shit on what side?My k drops to the right straight out of the box.Always did.So does avery body else's,I'll bet.The question is....By how much is it inclined to do that?
All I need to stop it is some light right knee pressure on the tank and maybe a bit of arse shift.
Martins idea is good but just ride the next Brick you find.
Title: Re: Bike goes to the right when ya let go of the bars...
Post by: TaosBrick on May 23, 2016, 09:01:52 AM
My apologies Johnny, the way I said it wasn't clear. What I meant was that you had to hold the whole bizness to the right just a leetle, to keep it going straight, ie Pull on the right bar.
Phew. Everyone's faith in physics and counter steering has just been restored.
   Yeah, something is putt whack somewhere, but where? Upon examination, I can detect no shims at any of the mounting points. Will have to check the links posted in previous replies to get an inkling of how that all goes. Thanks everyone, for all the interest in this topic. Everything else with this bike is GREAT runs smooth and strong, a real mile-eater. Now if I could fix this One Thing it would be as close to perfect as a beest with going on 70k miles and a few scuffs could be.
Title: Re: Bike goes to the right when ya let go of the bars...
Post by: 552255 on May 23, 2016, 11:41:55 PM
You can check frame/alignment with the string method, extending them forward on each side of rear tire, with carefull eyeball sight, ie. lying on floor to project the strings forward, on each side of front wheel, looking for it to be centered.  I had a bent frame, and found it to cause all kinds of issues...replaced it completely.  I rode it for many miles and chewed through rear tires before fixing it...
Title: Re: Bike goes to the right when ya let go of the bars...
Post by: Martin on May 24, 2016, 01:00:22 AM
552255 Bricks are offset as standard from factory by about .5".
Regards Martin.
Title: Re: Bike goes to the right when ya let go of the bars...
Post by: TaosBrick on May 26, 2016, 06:26:05 PM
Though the frame may be designed with an offset, I cannot imagine that it is also designed to drift to the right and munch rear tyres.
   So - frame shims. Again, where to install and how thick? As the bike is going right, my tenuous grasp of physics would lead me to take a Wild Ass Guess that the engine, transmission, and swing arm are cocked to the right as well. But how much? String method to determine?
Title: Re: Bike goes to the right when ya let go of the bars...
Post by: kennybobby on May 27, 2016, 12:00:44 AM
When you put the strings on it to check alignment you will find the centerline of the front wheel offset 5 to 8mm to the right of the rear wheel centerline. strings alignment (http://www.ibmwr.org/ktech/wheel-align.shtml)

The lateral position of the front wheel is determined by the frame.  The rear wheel position is determined by the engine, tranny, swingarm, and rear-drive assembly.  There are only 5 bolts holding the frame to the engine assembly, 3 on the right and 2 on the left.  The front left frame tube bolts to the head on the inner surface, which is on the right side.  So for mounting there are essentially 4 rights and 1 left.

So the addition of any shims between the frame tubes and the engine will only increase this offset as they displace the frame to the right with respect to the engine--there is no way to reduce the offset by adding shims.

i rode my white 75S for over 100k miles wearing out lots of tires and spent lots of time trying to figure out this stupidity and tried numerous things to get rid of the offset so i could align the wheels.

What worked the best for me was to 'de-shim' the motor mounts-- i used a dremel tool with a carbide bit to mill 1/4" off of the right-side of the front motor mount castings in the head and the block.  i think 3/8" would be better and then the alignment could be fine tuned by adding shims back in as necessary.

bmw seems to make good engines but they failed miserably at suspension design in both cars and bikes.
Title: Re: Bike goes to the right when ya let go of the bars...
Post by: TrueAce on May 27, 2016, 12:21:57 AM
That is real interesting stuff, KennyBobby. I would have been too anxious of unintended consequences to go mill the mounting surfaces. What affect, if any, did you notice in handling after that was done? Anybody else out there tried correcting the half-inch offset in the front-rear wheels tracking? Maybe one of our wizened old brothers know the engineering rational of BMW in that design.
Good info KB! And I loved your brother RickyBobby in his movie......he done good!
Title: Re: Bike goes to the right when ya let go of the bars...
Post by: The Dude on May 27, 2016, 12:42:02 AM
Shims can only do so much with little effect on overal geometry,angularly or simply offset.I would have thought for tyres to,wear,that bad etc.etc.its bent ,more,somewhere else...
I could not find any shims on my '86K75S frame/motor,trans.'probably forgot them on my last reassembly..

More to do with poor dimensional accuracy in the frame welding process needing packing to prevent stressing the structure on original assembly....by the mainly Turkish workforce....I could be wrong...I do have a single rear wheel spacer though.
Title: Re: Bike goes to the right when ya let go of the bars...
Post by: Martin on May 27, 2016, 02:01:17 AM
Go to the BMW internet riders website go to the section on suspension and check out Rob Lentini's article on checking wheel alignment.

http://www.ibmwr.org/ktech/wheel-align.shtml

Regards Martin.
Title: Re: Bike goes to the right when ya let go of the bars...
Post by: TaosBrick on May 27, 2016, 09:48:17 AM
Hmm... My idea is that this situation could be as much a result of the frame being tweeked to one side or the other, in addition to the aforementioned offset.
Thus, in comparison to the the headset, the engine/tranny/swingarm is at an angle, and with as I say, my limited understanding of geometry and physics, I would then hazard that the swingarm/final drive/rear wheel is cocked right of frame/headset centre line, thus causing the rear wheel to be pointed to the left, which then causes the bike to drift right.
  When I can actually not be RIDING the thing, or doing the other stuf I am doing on this trip, I will apply the string method to see what's what and report back...
Title: Re: Bike goes to the right when ya let go of the bars...
Post by: mystic red on May 27, 2016, 10:09:14 AM
To add to the mix, I have a RS wheel mounted to my LT which offsets the rear visibly and it does nothing to the handling or tire wear. I would look elsewhere.
Title: Re: Bike goes to the right when ya let go of the bars...
Post by: TrueAce on May 27, 2016, 10:23:02 AM
Another perspective would be this: imagine a normal rear wheel on a vertical axis at 12o'clock. But a slight imperceptible twist to the rear frame rails positions the wheel at 11:50, or even 12:10, now you will have "push" forces affecting the front end and unequal forces on the driving tire, and the front end.
Title: Re: Bike goes to the right when ya let go of the bars...
Post by: kennybobby on May 27, 2016, 12:07:17 PM
The frame is very simple and flexible--just some mild steel tubes welded to a central tube.  Any drop or wreck can tweak or twist the frame tubes or forks and cause the front wheel to be clocked.  It is easy to twist back if need be, just loosen the mounting bolts and get a long lever arm to put it where you want it.

i have made notes on hundreds of bikes at rallys to notice their tire wear pattern to determine that this was a design flaw before i started cutting metal--it was the only solution that made the bike track straight.  Look at that big honking piece of aluminum on the head frame mount--there's plenty of extra metal there that likely should have been milled at the factory. 

The other thing i could found was some old technical documents where the clever germans calculated that the engine rotation would generate a torque and so they designed an intentional offset in the wheels to counteract this.  Too bad they didn't test that theory before going into production.  Funny that there is NO other motorsickle builder that sees a need to have offset wheels.

some folks are more sensitive to suspension and handling issues than others, one of my super powers is hyper-sense for it and can jump on any bike and tell instantly if the handling is correct or not.  And i'm just stubborn enough to want to get to the root cause and fix any problems i try to solve--just like my brother Ricky...
Title: Re: Bike goes to the right when ya let go of the bars...
Post by: TrueAce on May 27, 2016, 07:28:38 PM
You da MAN, KennyBobby! Too bad we don't have a frame fig figured out for checking spec on these K's. Bet one could be figured out.
Title: Re: Bike goes to the right when ya let go of the bars...
Post by: Martin on May 27, 2016, 08:16:32 PM
I have tried to get all the alignment figures on the net, couldn't find them. I know there are books for all the alignment figures for cars when they put them on the aligner jigs. So they must be available somewhere, I tried the local bike smash repair shop but they are not open on weekends, so I will try them Monday. I was going to try the local BMW dealer but I don't think they will cooperate. Does anybody have a dealer that may give them the figures.
Regards Martin.
Title: Re: Bike goes to the right when ya let go of the bars...
Post by: kennybobby on May 27, 2016, 10:02:18 PM
Howdy Martin and Ace,

i added some screenshots from the factory service manual for the frame tightening sequence and shim placement, shim part numbers from the catalog, measuring wheel offset, checking the frame, etc. to my previous post, here (http://www.motobrick.com/index.php/topic,1373.msg6349.html#msg6349). 

The fixture for checking offset is shown in one of the diagrams, the frame-check fixture is also something that a good dealer would have in the tool room, but i've never actually seen one--although i've asked at several places.

i used a lathe to turn my own set of shims with up to 10mm thickness--tried them in various locations but it only made the offset worse.
Title: Re: Bike goes to the right when ya let go of the bars...
Post by: Martin on May 28, 2016, 02:39:46 AM
Thanks for the post saved me a trip on Monday. I'm lucky my bike tracks in a straight line and my tyres wear evenly.
Regards Martin.
Title: Re: Bike goes to the right when ya let go of the bars...
Post by: TaosBrick on May 28, 2016, 07:23:22 AM
Ah yes - now this occurs to me. Will all the folks who a lurking/posting on this thread that have K's which track STRAIGHT please chime in? I simply cannot believe that they ALL drift to the right.
Title: Re: Bike goes to the right when ya let go of the bars...
Post by: Elipten on May 28, 2016, 10:08:54 AM
Mine tracks straight. I looked at buying one that had the tires worn on one side. So I walked away


Sent from my iPhone using Tapatalk
Title: Re: Bike goes to the right when ya let go of the bars...
Post by: Scott_ on May 28, 2016, 10:53:08 AM
It's hard to tell about the straight tracking for me as I don't really have any absolutely "flat" roads around me. They all have some crown to them.
Either way, my tire wear is even on both bikes.
Title: Re: Bike goes to the right when ya let go of the bars...
Post by: rbm on May 28, 2016, 11:11:56 AM
My K75 tracks straight as well.  No tire wear anomalies.
Title: Re: Bike goes to the right when ya let go of the bars...
Post by: mystic red on May 28, 2016, 11:24:15 AM
The Fire Truck is on rails.... despite a noticeable offset.
Title: Re: Bike goes to the right when ya let go of the bars...
Post by: kennybobby on May 28, 2016, 02:19:07 PM
Hey all you straight and narrow trackers--are you setting the throttle lock and going no-hands on the bars?  That is the test for comparison, he is not asking about if it tracks straight when you are steering it.  Go find a stretch of road and do the test.
Title: Re: Bike goes to the right when ya let go of the bars...
Post by: mystic red on May 28, 2016, 02:32:50 PM
C'mon...... Throttle lock is so 20th century... Cruise control and I'm on rails.
The real story here is will I get to 3000 posts before Ichiro gets to 3000 hits?
Title: Re: Bike goes to the right when ya let go of the bars...
Post by: Martin on May 28, 2016, 02:38:42 PM
Homemade throttle lock set, hands off bars, standing on seat juggling chainsaws, tracks straight.  :2thumbup:
Regards Martin.
Title: Re: Bike goes to the right when ya let go of the bars...
Post by: The Dude on May 28, 2016, 04:21:05 PM
When I ride mine,especially doing a selfie,like in Taos' avatar ,Moto falls to the the right.Just a knee push on the tank and it's back straight.No uneven tyre wear,that I can notice.
Title: Re: Bike goes to the right when ya let go of the bars...
Post by: Laitch on May 28, 2016, 05:20:23 PM
That is the test you must do, this is not asking about if it tracks straight when you are steering it. 
That isn't a test I must do, kennybobby. Based on TaosBrick's first post, he's asking the rest of us if it takes effort to steer it in a straight line. His question is about effort.

It doesn't take any particular effort for me to keep my bike tracking straight. Its tires wear evenly. Obsession about its tracking straight when I'm not lightly controlling its handlebar isn't on my program nor is perfectly balancing the weight in all my gear pockets, side cases and tank bag.

Thanks for the link to the frame alignment rig and procedures, and thanks to Gryph for linking to the manual with the section on frame shimming.
Title: Re: Bike goes to the right when ya let go of the bars...
Post by: TaosBrick on May 29, 2016, 07:36:38 AM
In light of many of the replies I see here, I am thinking that the 'factory offset' is Not what is making my bike and others drift right. There is some other kind of tweak-age going on here that would seem to me to be frame or fork related. In my case, I strongly suspect the frame.
  Once again, I will not be able to check this until I get home. At least fresh rubber on the rear and both tyres balanced has restored my Brick's legendary smooooooothness, and made it so that the drift to the righ is a bit more tolerable. Good news for the 1,300 mile slab home.
Title: Re: Bike goes to the right when ya let go of the bars...
Post by: tsnap on May 29, 2016, 08:35:09 AM
Did you run a carfax on the VIN?  Someone here may have free access to the service.  It would tell you if there has ever been a reported incident on the bike.

tom, who knows so little. :tinhat2
Title: Re: Bike goes to the right when ya let go of the bars...
Post by: Laitch on May 30, 2016, 07:55:10 AM
There is some other kind of tweak-age going on here that would seem to me to be frame or fork related. In my case, I strongly suspect the frame.
In the K75 section of Bert Vogel's compilation of service bulletins accessible by a link in the Workshop here, there is this description of a simplified check for frame damage (http://hrsbstaff.ednet.ns.ca/bvogel/K100/download/K100-service-bulletins-and%20special-tools/2250%2Epdf).
Title: Re: Bike goes to the right when ya let go of the bars...
Post by: TaosBrick on May 31, 2016, 09:31:45 AM
Cool! Will add this to the string check when I get home.
Title: Re: Bike goes to the right when ya let go of the bars...
Post by: richarddacat on May 31, 2016, 09:55:51 AM
Mine will pull to the right so you are not alone.  :curvy-road

Slight pressure on the left peg will keep it straight enough to throw a glove on or for whatever reason I have for my hands to be off the bars.
Title: Re: Bike goes to the right when ya let go of the bars...
Post by: kennybobby on May 31, 2016, 11:13:22 AM
In the K75 section of Herb Vogel's compilation of service bulletins accessible by a link in the Workshop here

Is there a sticky thread of these bulletins, or where is this link in the Workshop?  Thanks, kb
Title: Re: Bike goes to the right when ya let go of the bars...
Post by: Laitch on May 31, 2016, 11:53:54 AM
Is there a sticky thread of these bulletins, or where is this link in the Workshop?  Thanks, kb
Go to the Motobrick Wrenching section, kennybobbly. You almost can't miss it.
Title: Re: Bike goes to the right when ya let go of the bars...
Post by: kennybobby on May 31, 2016, 01:17:24 PM
Well i suppose a little feller could miss it... if he were searching for Herb's list in the Workshop--especially since it's not Herb's, it's Bert's, and it's up in the Wrenching section, not the Workshop...but other than that you've been extremely accurate and helpful.

And so as to not waste time for anyone else on a wild goose chase, here is the link to the service bulletins sticky megathread in the Wrenching section
BMW Factory Service Bulletins (http://www.motobrick.com/index.php/topic,8029.0.html)

and this is the direct link to Bert's site Bert Vogel's Service Bulletin Collection (http://hrsbstaff.ednet.ns.ca/bvogel/K100/download/K100-service-bulletins-and%20special-tools/bulletins.htm)
Title: Re: Bike goes to the right when ya let go of the bars...
Post by: Laitch on May 31, 2016, 01:19:50 PM
No need to thank me, Kennybobby. I understand your tentacles and cap can get in the way sometimes.
Title: Re: Bike goes to the right when ya let go of the bars...
Post by: tsnap on May 31, 2016, 08:17:46 PM
xafrac

mot
Title: Re: Bike goes to the right when ya let go of the bars...
Post by: TrueAce on May 31, 2016, 09:10:55 PM
moT, you got a flair-up again of your "dixielexica"? Has anybody told you there are no Carfax reports on private sales of motorcycles? Just Sayin'....
Title: Re: Bike goes to the right when ya let go of the bars...
Post by: tsnap on May 31, 2016, 09:15:21 PM
it is not the "sale" it is the accident it may have been in.  Why would a "sale" affect a carfax?

mot the hoople.  just run a carfax on the vin.  what is so hard to understand?
Title: Re: Bike goes to the right when ya let go of the bars...
Post by: TrueAce on May 31, 2016, 09:23:04 PM
I'm asking if a motorcycle repair/sale/eetc would show up on a Carfax. You can't trick us spelling it backwards, I got a secret decoder ring.
Title: Re: Bike goes to the right when ya let go of the bars...
Post by: tsnap on May 31, 2016, 09:33:31 PM
google carfax. it varies from state to state.  I am amazed that this bike has not been checked, sooo simple.  I use it on Porsche cars.  I want to know if an insurance company has ever totaled the vehicle, or repaired it.

otm
Title: Re: Bike goes to the right when ya let go of the bars...
Post by: Laitch on May 31, 2016, 10:32:44 PM
You can't trick us spelling it backwards, I got a secret decoder ring.
I got a Vita-Mix.
Title: Re: Bike goes to the right when ya let go of the bars...
Post by: bocutter Ed on June 01, 2016, 08:56:34 AM
I got a Vita-Mix.
I got a Vita-Mix 5000, out of the treasure chest (dumpster), in perfect working order.
Title: Re: Bike goes to the right when ya let go of the bars...
Post by: Laitch on June 01, 2016, 09:08:20 AM
I got a Vita-Mix 5000, out of the treasure chest (dumpster), in perfect working order.
That's what I got, too, Ed! I'm stripping off all the plastic for conversion to a Hamilton Beach and will be starting a Projects thread.
Title: Re: Bike goes to the right when ya let go of the bars...
Post by: Martin on June 01, 2016, 11:06:25 AM
Laitch strip it down and make it a chopper. But you will then have to wear a bandana and vest preferably without tassels, don't want them caught up in the blades. :hehehe
Regards Martin.
Title: Re: Bike goes to the right when ya let go of the bars...
Post by: rrmode on August 26, 2018, 04:17:06 PM
Ok folks this has happened to my bike. My bike had been wrecked and the frame/triple tree was bent. I had to push quite a bit on the right handlebar to keep her straight. I replace the frame and all of the triple tree and I now have a bike that tracks straight and true. Hope this helps.

regards  rrmode
Title: Re: Bike goes to the right when ya let go of the bars...
Post by: beemuker on September 02, 2018, 09:11:57 AM
Mine pulls , but I've been to the great north [CT] without the brick and don't remember which way it pulls, I think I need to get my ass way out to the left when my hands are off the bars when  I'm shaving and putting on my makeup though ,so I'm thinking it pulls right. Will verify
later today.
Title: Re: Bike goes to the right when ya let go of the bars...
Post by: beemuker on September 06, 2018, 02:54:46 PM
Mine pulls , but I've been to the great north [CT] without the brick and don't remember which way it pulls, I think I need to get my ass way out to the left when my hands are off the bars when  I'm shaving and putting on my makeup though ,so I'm thinking it pulls right. Will verify
later today.
Yes, mine pulls right, not too noticeable until both hands are off the bars. I have to get my weight to the left to go straight.