My Terra has pretty much 9500 miles on the clock, just came back from an almost 2900 mile RT to northern Baja with lots of luggage and pavement pounding to get there. Started to service the bike at home and noticed I can move the sprocket hub on the cush drive loosely about 1/4" or so. So what the heck? Anybody checked there's yet? Have owned lots of bikes in my life, but that has never happened to me. Causes? Solutions?
Big singles do tend to put a lot of strain on the rear cush drive. With my old Yam XT660's (if the cush rubber was still in good shape) I used to cut out small pieces of packing from old plastic cutting boards to take up the slack. Others here I'm sure will have more to say, I have not really had cush-drive problems on any other bikes (just the Yam because the OEM cush drive rubbers were poor quality).
Thanks for the heads up. I will keep an eye on mine as it is an important component in preventing premature powertrain wear. I believe they wear out quicker when riding on pavement as the wheel can't break traction as easily on gravel or sand.
I'm not sure how the BMW hub is configured but there should be replaceable inserts to take up some of the slack. IMO a 1/4" isn't too much. I just felt my buddies new TR (Clete) the other day which had at least an 1//8th. I used to change my old KLR rubber inserts when they had 1/2"+ Is your chain slapping hard when you shift? The hub is doing it's job when it wears like it does and saves lot of wear on many parts (from piston to rear tire tread) on your bike in the drive train and reduces overall vibration and the related problems like cracked motor mounts, loose bolts etc.. Be happy that you have a cushhub to maintain
Having swapped back and forth between Terra and Strada mode twice now and about 8000 miles on the clock--I've noted just a bit of rubber from the cush parts accumulating on the inside of the rims, the drive slides in a bit more easily, and no "slop" but a bit looser. Me thinks its doing it's job in your case. The rubber inserts seem to be slightly less dense than the rubber inserts on my FJR (that has more than twice the hp potential), but seems to be wearing normally. If you think slop is excessive pull the hub and look yourself to see if the rubber is disintegrating unusually.
