cush drive rubbers symptoms?
 

Hi what are the symptons of knackerd cush drive rubbers? is it harsh vibration in the drive train or is it excess slop in the drive train? Are their any polybush type alternatives worth considering or is it better to just replace with OEM parts.

just push the sprocket forward & aft... that will tell the story..

As has already been mentioned, rotational play at the rear sprocket is the way to tell if the cush rubbers are knackered. The symptoms are snatchy take up on and off the throttle. Harsh vibration in the drive train is much more likely a knackered sprocket carrier bearing (which can be a result of prolonged riding with worn cush rubbers). To check this, grab the sprocket at opposite sides and push/pull on alternative sides looking for play.

In my experience there seems to be little difference between OE and pattern parts, they both fail miserably after a few thousand miles. You could try the inner tube packing mod to get more life out of them. There are polyurethane ones available from hunday of this parish, but he can be a bit elusive and hard to track down - contact him by email, rather than PM and keep persevering.

lol.... no... But I did use to build alloy offshore yachts...
have done a hour or two on them..

How many is a few thousand miles?

I replaced the OE set as a precautionary measure before a big trip at 5,700 miles, the pattern set from Wemoto is now at 10,000 miles.

They do seem a bit loose in the hub and are keen to fall out but I've not noticed excessive rotational play.

Probably worth saying the gear change is a bit clunky, in the way I'd associate with a slack chain but both clutch and chain are correctly adjusted.

Over the last six years I've generally replaced them every other rear tyre change, so about 7000 miles. However, I packed them out with inner tube each time I changed tyres in between.

Cush drives
 

Im on my second set of cush drive rubbers ( one set sent to me as a warranty replacement ( and a set of headstock bearings) after i kicked off with yammy.))

Ive never had a bike with such crap parts on it. The new rubbers were sloppy as soon as they were fitted and you can really feel it snatching when on and off the throttle.
Ive got to the point now where i put a bit of mastic into the spaces between the cush drives before i put the wheel back in the bike but its still ****e.

Getting a bit sick of it now.