www.boxertrix.com

This is out of curiosity and not in relation to a problem, if anyone can tell me.

There is a difference in the assembly method, if not principle of operation, between the Telelever system found on models with clip on style bars versus those models with upright style bars. That can be clearly seen.

What I assumed, but don't know for sure, is that the models with upright bars (GS, RT, R) have a rigid yoke main bearing, as opposed to the other types which have a ball joint as the main yoke bearing. Therefore the stanchions on the upright bar versions pivot at the top end. Is that right?

As an aside, are these pivots, on the upright bar versions, actually rubber bushes and not metal ball joints?

Thanks.

http://www.ukgser.com/forums/showthread ... ad+bearing

There appears to be rubber metal bushes In the top yoke and a ball bearing in the centre. Max bmw website parts fiche is good or uk Gser.
http://www.maxbmwmotorcycles.com/fiche/ ... v=04302013
http://www.maxbmwmotorcycles.com/fiche/ ... d=04302013

[quote="nab 301"]http://www.ukgser.com/forums/showthread.php?t=303879&highlight=head+bearing

There appears to be rubber metal bushes In the top yoke and a ball bearing in the centre. quote)

Thank you very much for that help. Looks like I was on the right lines. As I say, this is for my curiosity and anyone else who may be similarly interested.

So, it seems there are some significant differences between the two basic versions of upright bars versus clip on style bars (GS style versus S style). The suspension top pivots are rubber and not an all metal ball joint for a start. But what intrigues me more is how the steering itself functions.

On the S style system it seems the rake angle varies, relative to the frame of the machine not the ground, as the front suspension goes up and down. The steering pivot point centre distance continuously changes too. Because each steering pivot point is a ball joint.

But on the GS style system things are different. The top steering pivot is fixed, in that it can only rotate in one plane, but the bottom steering pivot is a ball joint. So, does the bottom ball joint determine the rake angle? I can't see how it can, as the top steering pivot is fixed. Surely this bearing determines the rake angle? Can we say that the rake angle on these types is fixed? Fixed relative to the frame of the machine. More like a conventional bike. If so, then that is a significant difference between the two types.

I have both the R1200GSA and the 11S. The 11S has a pivot top and bottom yoke. I have not taken the 12GSA apart so can't answer, not even by looking at the drawings and description. Best to give Steptoe a pm. I bet he has taken a few of them apart so he could answer your question.