Chain loose, wheel nut seized tight

[Scotty]

Turns out the sprocket carrier bearing was shot and the seal gone.....

As a matter of interest, was there a spacer inside the sprocket hub, between the carrier bearing and the wheel bearing on that side? If that spacer had been omitted when they refitted your wheel, the carrier bearing would be destroyed in next to no time.... :-?

[b_m1957]

Scotty, do you mean part # 12 on this diagram?

Sprocket carrier bearing (and wheel bearing) now replaced and all seems well at the back end.

There's definitely something wrong at the front end now; once first gear is engaged (on paddock stand), the chain starts jumping around and seems to snag, making the whole bike seem to jump.

I don't think any teeth are buggered, I'm more inclined to blame the drive shaft bearing. Hope to get my hands on a decent allen key at the weekend to try to get the crank case cover off and have a look.

Any thoughts on what's most likely/anything I've not thought of???

Cheers

[alanTDM]

Chain might be knackered with some stiff links that will cause a jumping sensation as its not going round the gear box sprocket correctly so its jumping
Put the bike on the paddock stand and turn the wheel with the sprocket cover off ,if its stiff links you will see them.

[b_m1957]

Chain might be knackered with some stiff links that will cause a jumping sensation as its not going round the gear box sprocket correctly so its jumping
Put the bike on the paddock stand and turn the wheel with the sprocket cover off ,if its stiff links you will see them.

I've had the sprocket cover off... nothing obvious in there and chain seems fine.

Could a loose sprocket cause the 'jumping'? It seems to be coming from the transmission, so it looks like I could be learning the hard way how to take an engine apart :'(

[alanTDM]

The sprocket is on splines there should be no fore and aft freeplay I know some bikes eg some Fazers and TDM's the front sprocket nut comes slightly loose but there should be a locking washer holding the nut.A new sprocket nut usally cures that with loctite and new locking washer.
To find out if it is your gearbox take the chain off the sprocket and run the engine in the gears if you still got the noise then its a gearbox problem if not its chain related.

[alanTDM]

If sprocket is starting to look hooked like this then its fooked.That will give a knocking noise and normally only in the 1st or 2nd gears at certain low rpm eg pulling away from juctions

[b_m1957]

I'm pretty sure the sprocket itself looks ok

[alanTDM]

Seems to look ok to me

[Rossio]

Mine done the same, apparently a tight spot in the chain can make it do it, I'm changing my chain sprockets anyway as the cheap option first il let you know if it cures it.

[b_m1957]

Chain off the front sprocket and still making horrible noises :-[

Not as bad but I guess that's to be expected with no turning resistance.

Haynes manual and some basic tools bought - I guess I'll be learning how to take an engine apart ;D