Cush drives - questions ... - Ducati.ms

fasterdammit · Jun 5th, 2006, 10:03 am

What's the life expectancy on a set of cush drives, on a street-only bike? I've got a '97 m750 and I just put a new sneaker on the rear end this weekend (Pilot Powers - w00t! w00t!), and I noticed that I can compress the sprocket by hand - which I'm not sure whether I should be concerned or not? There's no rotational movement, but I can decrease the gap to the rim by pushing on the sprocket. It doesn't touch, but I'm just curious what I'm looking at here. Should there be some compression room? Am I still good if there's no real rotational flex or slop?

I don't stunt the bike, but I certainly ain't driving miss daisy either; we're at 38k miles, and AFAIK, these are the original bushes. I know these don't exactly pop out with a smack on the back either ... what am I looking at in terms of replacement/maintenance, anyone?

Thoughts/suggestions/advice greatly appreciated!

jack · Jun 5th, 2006, 11:41 am

Solvents and gas would have an effect on the rubber, as would UV (sun light) and heat. Solvents like acetone, toluene or MEK would potentially make the rubber softer and expand or distort into odd shapes. UV light and heat would potentially make then the rubber hard and prone to cracking when loaded. I would guess that there is less surface area in the compression direction, than in the rotational direction, which is why you could see it compress but not twist. If you can't any visual defects when removed I'd say you're good to go.

breakout · Mar 27th, 2007, 12:15 pm

Quote:

Originally Posted by jack

Solvents and gas would have an effect on the rubber, as would UV (sun light) and heat. Solvents like acetone, toluene or MEK would potentially make the rubber softer and expand or distort into odd shapes. UV light and heat would potentially make then the rubber hard and prone to cracking when loaded. I would guess that there is less surface area in the compression direction, than in the rotational direction, which is why you could see it compress but not twist. If you can't any visual defects when removed I'd say you're good to go.

rotational play is determined by the drive rubbers; axial play by the plain bearing in the sprocket carrier center, look at it, replace if neccessary,the bearing is not completely centered on the sprocket, possible contributor to thrown chains;- that will make you cry!!!