Cush Drive

[Flip]

While playing about with the rear hoop yesterday afternoon I gave the chain a bit of a clean and while doing so I noticed a bit of play in the cush drive when rocking the rear sprocket.

There is no sideways movement, only in line with drive but it sounds very solid- almost metallic rather than just movement.

Before I whip the wheel out and look are the bushes in the wheel knackered or is it likely to be the parts on the hub?

[Flip]

Oh come on, I know a fair few people here have changed them- what were the symptoms of them wearing out?

[slob]

only the need to powder coat in my case

[jerry]

I have changed them on my 750ss when 4 a bit sloppy were loose , cant say I feel any difference with new ones may be a bit less slack in drive train ??? my monster is still on originals as is my S4

[Nottsbiker]

Took mine out for powder coating but never rode the bike complete I'm afraid

[Dennis menace]

Other than the cush drive rubbers there is not much to wear out in the hub apart from the hub bearing (it sits in the hub casing). That might be the metallic sound you describe. It is the same size as the wheel bearings on my 750SS but don't rely on that info. The bushes on mine were a sod to get out so I rigged up a puller (bolt and big washer on the back, socket and nut on the outside). You will see if the cush drives are knackered as the rubber parts from the metal inner or outer or both. Got my replacements from MotoRapido for about £63:

http://www.ebay.co.uk/itm/Genuine-Ducati-Spare-Parts-Cush-Drive-Bush-Set-Monster-Supersport-70090051A-/181976548808?hash=item2a5ea5c5c8:m:m8MGdm1C79IJ03n C8HeyVpA

Use new nuts on the cush drive bolts.

[utopia]

I haven't had to change mine but I have a bare wheel in front of me.
The rubber is quite thick, maybe 7 or 8 mm, so if that has broken up (on all six bushes) enough to allow metal to metal contact it looks like it would cause a fairly massive angular slop.
On the other hand, the pins themselves do make metal to metal contact ... but I would have thought that wear in those would be relatively unlikely.
Which leaves the bearing, I guess, but there's very little movement there anyway so that doesn't seem likely either.
Not much help probably, but maybe it'll prompt a thought ...?

Note that the pins themselves have r.h. threads for the sprocket nuts but l.h. threads into the cush drive hub.
I'm sure you would be onto that, but it doesn't hurt to make sure.

edit ... nope, the comment about the bearing is complete cobblers.
I leave it for your amusement though.
If I was thinking at all, it was about the very little RELATIVE movement between the cushdrive hub and the main hub.
But of course the bearing works just as hard as the other two.

[Albie]

only the need to powder coat in my case

Same here. Told had no need to after by powder coated.

[Flip]

Thanks for that everyone, I didn't think much could wear other than the rubbers but obviously it is a slightly different arrangement to a 'normal' cush drive where there are V shaped tangs on the hub that fit into V slots in the rubber cushion.

Before I take out the back wheel to see what's what can somebody please see if their bike is similar.

If you take hold of the rear sprocket and rock it back and forth in the line of drive and let me know if it makes a noise- if there is free play of course.

Thanks!!

[utopia]

Well, with the wheel out of the bike, cushdrive assembled but no wheel spindle fitted, there is a slight knocking as you try and turn the sprocket back and forth.
There clearly is a minimal amount of movement (between the pins and the inner steel bushes of the rubber doodads) but its virtually impossible to put a figure on it or even see any actual movement of the sprocket at all.
This is a unit that has done 19000m, mostly by myself and without abuse (all on the original chain).

ps. spotted the old spindle on top of the microwave so tried it with that fitted ... no change.

[Mr Gazza]

Cleaning the back wheel the other day with the bike on the rear paddock stand.
I noticed a noise when turning the wheel.
It was a stange noise, not metallic in any way but a sort of groan or creak in one particular spot on the rotation...This is exactly how I discovered that my rear disc was warped, but pulling the pads back confirmed that it was not the disc again.

It seemed to be coming from one of the cush drives...I could actually feel the vibration on a particular sprocket nut when I put my finger gently on it while turning the wheel through the arc that made the noise.
I removed the nut and tried it again...still the same...replaced the nut...Still the same.

I wiggled the sprocket around and in and out, but found no play in any direction.

I sprayed silicone into the cush rubber as best I could, but wasn't sure if I had got any into anything that would make any difference...It didn't.

Decided to keep an eye on it and went for a ride.

Remembered it a little while after the ride and checked it.....All gone??????????:scratch:

[Flip]

Just had another little look and the movement is actually a lot less than the noise suggested so I think it is amplified by travelling up the hollow spokes and into the air space of the tyre as when I put my ear to the hub it doesn't seem anywhere near as loud.

Funny the things you notice while doing other bits eh?

[Dukedesmo]

I changed the cush drives in mine because of powdercoating the wheel (they looked OK otherwise) and the new ones are fairly tight on the sprocket carrier, certainly no play. In fact I reassembled with some copper grease in them as there was a small amount of corrosion and I want it to come out easily next time...