.: XT660.com - The #1 XT660 Resource :. - solution to the cush drive problem

.: XT660.com - The #1 XT660 Resource :. ( https://www.xt660.com/index.php)

- General Help Section ( https://www.xt660.com/forumdisplay.php?f=43)

- - solution to the cush drive problem ( https://www.xt660.com/showthread.php?t=14576)

solution to the cush drive problem

Like most other XTX owners I've had to replace the cush rubbers in the rear hub way too often.
After the third set of rubbers I took a closer look at the hub design.
Looking at the bearing boss on the wheel I saw evidence of contact with the sprocket carrier pocket, this should not occur, as there is clearance between the two.
The solitary bearing in the carrier is not up to supporting the load from the drive chain and twists under load and makes contact with the bearing boss.
(your hub will probably show scarring from this contact like mine did in 2nd picture).
This twisting action chews the rubbers to pieces inside the hub.
My solution was to bore out the pocket in the sprocket carrier and press in and loctite a machined plastic bush (UHMWPE) with a clearance between the bearing boss and bush of about 0.2 mm ( just enough to allow the hub to rotate without binding), I then coated the bush / boss contact with grease and assembled (1st picture).
That was around 5000 km ago and the rubbers are looking good, there is still some wear as the rubber is crap but the rapid destruction has gone.

That's a clever solution, mate. By the look of the design, there shouldn't be as much flex as there obviously is. Might explain chain derailment, to some degree, when combined with wear in all the external driveline components.

Nice find, they should never touch like that, I would be replacing the sprocket holder bearing as well.

Even with my 57HP XT motor the sprocket holder did not touch the wheel hub, like that.

Quote:

Originally Posted by Kev (Post 134768)

Nice find, they should never touch like that, I would be replacing the sprocket holder bearing as well.

Even with my 57HP XT motor the sprocket holder did not touch the wheel hub, like that.

Thanks for the comment Kev, interesting your bike did not show the contact in the hub that mine did, I'll be changing the bearing soon.
Just some notes about the mod, because of the damage to the bearing boss I polished up the scarred aluminium with "wet & dry" so it did'nt cut up the plastic bush & the thicker you make the bush the better to give it some strength.
A couple of "perceptions" after doing this were the bike felt to have less driveline vibration and the throttle response felt sharper, more instant, perhaps because the torque is no longer twisting the hub but pulling directly in line now.

Quote:

Originally Posted by piggar (Post 134812)

Just out of interest - did you try the 'bits of inner tube' mod? I did it a couple of thousand miles ago to save replacing the cush drive rubbers and all still seems fine. I saw no sign of contact between the sprocket carrier and the hub that I can recall anyway.

Hi Orangejohn, yes I do run the "innertube mod", but I found although it took the slop out of the hub it did'nt prevent the metal to metal contact in my wheel.
I felt it was this twisting action that was doing the most damage.
Piggar.