Subframe alignment R1100S (Post wreck)
 

I laid my R1100S down at a track day and broke the upper rear subframe attachments points off as detailed in the following threads:

Thread 1

Thread 2

Thread 3

I had the tabs welded back on and added gussets for added strength. When I mounted the rear subframe last night, and a stood the bike up, the very back of the frame was off by about 1/2“ to the right side. I had picked a center point on the rear subframe and dropped a plum-bob to confirm this. I had the bike held upright and a level to check for any lean.

On the to the questions. Is there any chance the frame is off on these bikes and this is not something I should worry about? Doing some math, 1/2” at the back of the frame is 1/8" at the tabs, so can I elongate the holes without compromising the integrity of the bike? Short of buying a new subframe, is there an easy way to tell if the subframe is bent/twisted/etc? Any other thoughts or suggestions on this?

Hey Andy;

I have a used sub-frame from beemer bone yard I will sell your for a great price if you are interested?

Thanks for the offer, I will let you know if I go that route, I would hate to buy one and find out mine is not out of alignment.

Some thoughts:

Are you sure that the center stand isn't bent?

Not sure what you mean by you "picked a center point and dropped a plumb bob". Could you elaborate?

How are you measuring level - what reference points are you using?

The rear sub frame really only holds the seat and exhaust up, and has no effect on operation of the bike. Don't do anything rash that might spoil the rest of the riding season for you.

The bike does not have a centerstand, it is in a baxley chock. I checked level across the triple clamps, front forks, frame and rear wheel.

I still have the plastic tray that mounts to the underside of the subframe attached to the subframe, and picked the center point by centering a line between two screws on the plastics, I dropped the line from there. Looking at the bike from the rear, you can tell it is off. I think the aesthetic issue is the biggest, the issue should not impact ride-ability other than if I am seated biased to one side and my left arm gets more fatigued by reaching further than the right.

Uh...you do know that the rear wheel is not centered on these bike, right? It is off by 1/2 inch or so.

That was what I was looking for then. The subframe is biased 1/2" to the right side (when sitting on the bike).

No. The sub frame is straight. It is the rear wheel that is biased to one side.

Sorry, but I'm not sure (from memory) which side it favors. Perhaps someone provide that info.

I think that is what I meant :D

From the S pdf manual, page 251 (sect 46.3) - it looks like the rear wheel track can be offset up to 9mm to the right (if I understand correctly, and I may not :)).

Hey Andy, it's good to hear your bike is getting fixed and back on the road. I'm the guy who was at the trackday and offered help if you needed.

Later,
M

I hate that Andy had to dump his bike for this topic to come up, but at least I might be able to learn something from it.
I have the 5.5" rear wheel and am missing the spacer that's usually there. I seem to remember Bobby from BMW Atlanta saying we need to add spacers to help offset this factory offset and make the bike turn quicker.
What's the consensus on this? Since it's already 9mm off, I'm sure the wider wheel is part of that, but how many spacers would it take?