Great Day and Ride / Minor Drive Issues

[Houdini]

Saturday we experienced record high temps at ~74 degrees, a great day for a ride and refresh on the bike.

A minor annoyance keeps coming up on initial launch only.
Appears to be the rear cush drive area. Imagine you are on a riding lawn mower & selecting the blades with the drive pully, at the last second the blades engage and the belt drive system makes a lurching / "grinding" noise.

That's pretty much what my rear cush drive feels and sounds like when I launch from a stop under normal circumstances...I can also feel some slack being taken up in the system between decel / clutch / accel situatations.

Additional maintenance / condition details from my previous post below:

http://www.thegsresources.com/_forum/showthread.php?t=130746

Happy holidays !!!

[Calvin Blackmore]

I had to replace cush rubbers once...
but a metallic sounds isnt right maybe the bearing int he sprocket hub is failing?

Do you have abnormal wer in the sprocket teeth? are all mounting bolts tight?
pictures would be nice alos

[Houdini]

Bike has only 7K miles, of course its 28 years old. I had the drive apart ~2K miles ago and inspected the cush drive rubber, bearing (s)...all "looked good and felt smooth. Only item that looked unique was some very slight .030 galling on the spacer (90 deg arc) that rides in the seals on the drive side ( i removed the slight high metal). I could not see any corresponding galling on the hub / bearing...like a rock / chip may have gotten in between the spacer / hub at 1 time...again all felt smooth with no other contact / roughness of any sort...??

I also replaced the rear sprocket ~2K ago with new washers, all nuts tight then and now.

Could a cush drive bearing go bad and not feel any roughness in 4K miles when the problem 1st started or would the cush drive rubber deteriorate due to age and cause this?

[Calvin Blackmore]

ok so maybe its the clutch
have you cheked the thickness and flatness of the fibre and metal plates?

Of course tht requires a gasket and some mess
I wonder could it be clutch spring sag as well you can get all the specs form a manual I am sure there is one kicking around on someones links.

[SqDancerLynn1]

Could be the chain ?

[chef1366]

Sprockets? Chain? Rear wheel adjusted cockeyed?

[Houdini]

So, I bought the bike with 3K and the problem 1st started at 4K, gradually getting worse from intermittent to now every normal launch unless I really feather the clutch. When I replaced the rear sprocket (45/41 for taller gearing) at 5K, I noticed the axle was evenly aligned on the swing arm markings. After splitting / reducing the chain and adding a 530 master link I removed the chain guard to feed the chain easier, aligned the swing arm marks and visually checked the chain / sprocket / wheel alignment; all looked good... So it was "in alignment" for a while before starting to make the launch noise, gradually getting worse from intermittent to now every normal launch unless I really feather the clutch.

Houdini