Now that I've taken the 916 apart I'm looking to various consumables which I might need to address. Does anyone have experience of the urethane cush drive cushions? The price difference between them and OEM seems enough to warrant asking the question. The bike had only done two track days at brands before being parked up for ten years, so for me it's the going round and adressing anything made of rubber as probably needing replacing. I've got a renthal rear carrier to go on it when its time to reassemble.
Replacing rubber components with urethane is common in the car world but I have not seen it much yet in bikes. Urethane will be stiffer than the rubber equivalent and is likely to reduce the radial movement in the rear sprocket that results from applying drive through the chain so on and off power might feel a bit more jerky until the urethane begins to degrade. Andy
Replaced mine with OEM just after I bought it in 2005, done about 40,000 miles since then. Got a Renthal carrier too, so they can't "walk" if they fail, but they look ok.
My original cush drive rubbers are 18 years old and in perfect condition. I'd question the need to change them just for the sake of it. I only replace parts that are sub standard
I had one split and eat into the eccentric on the rear hub which made a right mess so, I'd keep an eye on old ones and/or fit a carrier that keeps them together...
Yes, that's the one. It audibly 'popped' a few miles before we got there, at first I didn't know what had happened but it soon came to light once examined. It milled the eccentric adjuster away to a couple of mm in less than 10 miles of riding and I had to get the breakdown van home. The hub would still hold together but adjustment would have been tricky, luckily I managed to find a replacement quickly and at a reasonable price and I now have a Renthal carrier with the stops on it.