R100gs -fitted new M-shock and rear wheel now locking up when on stand

barny

Well-known member
UKGSer Subscriber
Joined
Jan 14, 2007
Messages
1,833
Reaction score
372
Location
Tractor Central, Norfolk
As title just fitted New M-Shock which is about 5mm longer than the standard shock. With the bike on the main stand the rear wheel will lock mechanically when turned. If I raise the FD about and inch or drop the bike off the stand the wheel will turn freely. I do have a clearance problem with the rear tyre to shock but that is not the problem. I know I did not have the problem prior to fitting the shock as I adjusted the rear brake a few days ago when I re-assembled the rear end following fitting one of Mikey's rebuild gearboxes. Just prior to fitting the new shock I ran the bike 30 miles without a problem. Can anyone shed any light on this, is it because I am turning the rear wheel and its not the engine end turning things, currently I have not run the bike because I am wondering what would happen if the rear wheel got light over a bump etc would the rear wheel lockup.

Thanks for any views

Barny
 
Could it be the joints on tbe shaft is the angle too acute for them. Are the joints healthy?
 
Have you actually physically checked the length of the new shock against the old one?
 
What sort of drive shaft do you have ? - the new rebuildable style are a fraction larger and can require a bit grinding on the inside if the swinging arm to even fit them, so as Mikey says it doesn't take much to make them touch, even with a standard shaft.

You don't really want to change the angle of the dry driveshaft anyway, as any increase in the angle results in a power loss which is expressed as heat in the UJ's.

Not a huge problem on the wet monolever shaft as they are cooled by the oil, but with the dry shaft the extra heat forces the grease out of the joints and they don't last long without grease.

Which is why serious bikes have the motor remounted higher at the front to keep the drive straight.

If you are trying to speed up the turn in a little lowering the front is a better idea, but on my 93 GS the fork tubes hit the "dash" PDQ.

If you are trying to increase the wheel travel and ground clearance you have probably bought the wrong bike.
 
Well I may have bottomed this out now, I have been in-touch with M-Shock - Mike Capon it turns out the shock is about 10mm too long it would seem there is a spacer missing from behind the piston so shock is going back for correction. Mike was very good probably one of the best adverts for M-Shock we discussed the problem he has sent a UPS return label within minutes and the shock has gone. If anyone is looking for a shock for a BMW airhead check the bottom mounting apparently there are different diameters mine was 15mm they seem to vary mine was too tight so let them know the size to save disappointment.

Update to follow. Thanks to all.

Barny
 
Nippy Normans supply Touratech, Wunderlich, Desert Fox and many other makes of accessories.
You must log in or register to reply here.


Back
Top Bottom