I resolved a similar issue on my Y2K 1150GS. Though the bike would track straight, it seemed the handlebars were pointed slightly left while riding in a straight line. Thinking that by re-torquing the axle while the fork bracket bolts are loose, it might help re-align things if they are out. I loosened the pinch bolts on the fork bracket (#10), the pinch bolts and the axle. Retightened in this order: 1) Axle. 2) Axle pinch bolt right side. 3) Axle pinch bolt left side. 4) Fork bracket pinch bolts, being careful to tighten top and bottom on same leg evenly. When I got to the fork bracket, I noticed the left leg was lower in the bracket than the right. The difference was minimal, but I could tell by making a visual comparison in the machining in the leg above the fork bracket (circled in red in diagram). To remedy, before tightening the left leg I loosened the axle and pinch bolt left side, tapped the bottom of the fork leg with a plastic mallet until the two fork legs seemed even, then tightened up everything starting with the axle. Not sure if I had a twisted leg, or if the problem was a lower left fork leg or combination of both, but the procedure remedied my situation. I hope this helps. Cheers!
That was for later models I believe. My 2000 model does not have or require one. Was that spacer not required for brake calliper clearance?
If you lay a piece of glass on the fork tubes it will indicate if your forks are twisted in the triple clamps or not. The top clamp should line up with the bottom and if so the glass will lay flat and not rock. It is easy enough to fix if they are out of alignment, assuming again that they are not bent.
No placebo effect will make the bike turn. If the windshield is not straight, the wind will push harder to one side. Maybe it's only an issue with Tobinators installed.
It was also the first time I had ever taken the wheels off the bike since owning it. Maybe you put it back together a bit wrong or twisted? Try taking it apart again, clean any dirt/grime from the wheels, speedo gear, check all is correct and re-install. I've got a 2001 1150GS that tracks straight and true no matter how off-balance the side cases are. Most of the time my save-yer-own-ass tool kit (tire irons, repair stuff, pump, etc.), first aid kit, 1/2 cover, ROK straps, and assorted other crap are crammed into my left side case and the right will have a bottle of water and a jacket liner = very unbalanced with no noticeable drift or lean. I do notice, however, that it falls into corners differently when one side case is significantly heavier than the other. I have never experienced the PTTR (pull to the right) phenomenon common on older RTs. Speaking of older RTs, I had a 1997 1100RT that really did PTTR regardless what I did to it, and it was significantly more obvious if the bags were unbalanced. The previous owner of that bike had boinked into a curb pretty hard, so the front end was tweaked. I had a BMW shop go through it and they found that the ball joint on the telelever (#10 in the drawings above) had been knocked hard enough to make it very slightly bent, so I replaced that and it REALLY helped. They disassembled the forks and found one was very slightly bent (replaced slider), checked the clamps, axle, ABS ring, all OK, front wheel (slightly bent and replaced), and put it all back to spec. The PTTR thing was still there but it was very mild, could be overcome by adding a little weight to the left side of the bike (like a couple pounds of stuff in the little glove box in the fairing). If I remember correctly, most people thought the RT's PTTR issue was because the rear wheel tracked slightly differently from the front (both were running straight down the road, just on slightly separated parallel lines) and an aftermarket shim would have aligned it better, but it was never noticeable enough with proper loading that I felt it was necessary. After getting the front end repaired I just rode it 50,000 happy miles before selling it. My GS has never had that issue. I say take the wheels back off, look everything over carefully, compare to pictures in a good shop manual, clean everything real good, put it back together again and see if that helps. I did a tire change and balance thread for the GS a few years ago, maybe this will help: http://www.advrider.com/forums/showthread.php?t=148614 Doug<!-- / message -->
Sorry that I just saw this. I participated in a long thread on the topic of BMW motorcyle pull, specifically the R1100 and R1150. It's a long thread, which you can read through, here, about the middle of the thread. The bottom line is that weight imbalance. even as little as 10-12 lbs. can cause a pull, either to the right or left. Rear wheel offset of 3-5 mm can also cause a similar pull. Is there any side to side fuel imbalance in the 1150GS? There is about 15 lbs. fuel imbalance in the RT. On my RT I ended up putting 12 lbs. of lead in the left hand "glove box" where a radio can be mounted. I can now ride hands free. RB
Yes however, this gauge looks costly. I would speculate that few BMW dealers would invest in what appears to be an expensive tool that would be used infrequently, instead relying on less sophisticated techniques for measuring GS wheel track offset. I would call a couple of close dealers and inquire. The math for determining wheel track offset (S) is as follows: S=A+Fh/2 - B+Fv/2 Permissible wheel track offset (S): ± 9 mm (0.35 in): datum is + 4.5 mm (0.18 in) Excerpted from BMW REProm.
So I've taken both wheels off again and tried to straighten the front forks, all with no luck. While I was toying with the rear wheel I noticed it has a tiny bit of play. I'm wondering if this is causing the issue I'm feeling. I also, somewhat unscientifically, tried to figure out the direction of the rear wheel with string. It seems the wheel is pointing slightly to the right side of the bike. Paralever bearings?
FourG, hi! Hope you don't mind me reviving this thread, but just curious how you made out with finding the alignment issues? Thanks! Liz
Unfortunately I haven't resolved it yet. I took it to a dealer to have them "diagnose without Diagnosing" and they seemed stumped as there was nothing obvious. I may be bringing it to an alignment specialist in the north bay soon.
Put it on the center stand. Be sure the tires are fully seated on the rims with proper air pressures. Are your wheel straight and true? Spin and eyeball them to check. Put a straight 2x4 on edge (2" side against the tire) up next to the tires to align them straight. Do they line up? It may be a bit touchy because the front and rear wheels aren't the same width, but it can be done. You can clamp the 2x4s to the rear wheel and use equal spacers on each side of the front wheel to get it clamped in. Accurately measure from the ends of the axle back to the foot pegs (assuming the pegs aren't bent) to make sure your front wheel are is in line. If the wheels are out of alignment or the front wheel/axle measurement isn't the same on each side, loosen and adjust triple clamps to get the measurements equal and the wheel and forks in line. Leave the wheels clamped straight. Accurately measure from each handle bar end to the front axle end and from the handlebar ends to the foot pegs. It should be the same on each side. Accurately measure from handlebar ends back to the luggage brackets. It should be the same on each side. If not, the bars are bent. Still seems to wander off? Put it on the stand on level ground, clamp the wheels again and check vertical alignment of the front wheel with a plumb bob or a level.
FourG, hi! Thank you for the update. It's certainly a curious dilemma. Just wondering, do you have a friend who you could swap wheels and tires with for a ride? The only reason I ask, is you mention you had put on the new Tourances, and a week later you can feel the pulling more than ever. Thanks! Liz
Hi! unusual to see a new thread / topic in the gspot after a while.... anyway, I am going to suggest the driveshaft in the paralever. Years ago I pulled mine and when re-installing, I didn't aline the UJ's correctly (there are a few other topics in here about that) The caracteristics of the bike changed some what, would fall in to right hand corners and I had to really work it to turn left. Whilst you note you haven't done anything to the paralever, I am putting forward that there could be wear in it that is causeing the pull to the right. I suggest that you check everything else first, start with the simple items and work to the harder. (Its not hard to pull the drive shaft though) Hay Ewe
Hi I was thinking abotu this some more when I rode my 1150GS to work this morming, quick things Take the panniers off - remove a varible - do a road test take the windshield off - remove a vaible - do a road test do the above two one at a time so if there is an effect you know which one it was Is the direction of rotation of the tires correct? sounds like a silly thing and I dont know whyit might make a difference but some thing has changed and you said that had changed tires - some thing easy to check I like problems like this, something to think about - thanks Liz for reviving it Hay Ewe
Most of the reason for pull is a side to side weight imbalance. As little as five pounds can keep you from hands free riding. To counteract this there is often a rear wheel offset on the R1150, each 2.5mm of rear wheel offset counteracts about 5 lbs. of side to side weight imbalance. Try adding 5 lbs, at a time to the side opposite the pull and see how much it takes. Here is where I ended up on my 1150RT.
Not an expert by any means, and you said the dealer is stumped, but if the rear wheel has play doesn't that immediately point a finger at the final drive tapered wheel bearing? I'm not sure if you mentioned the mileage on the bike, or previous FD maintenance, but 1150 FD's have a tendency to self destruct somewhere between 50K and 100k miles. Could post several linkys here, but here's the most obvious one. Did you eliminate this as a possible cause?
