Odd noise

[Nell]

Wheeling my XBR out of the garage before a run - quiet - no noises.
Wheeling it back into the garage after a run - a loud regular clack-clack-clack noise from the gearbox / transmission area.
Any ideas why?
The  bike runs well and the noise only occurs while pushing it in neutral when the engine and transmission is hot. It has done this for some time and I have just ignored it.
Now I am curious.

[Andy M]

Could be all sorts. Pull the clutch in and try pushing, turn the engine over on the kicker and repeat, apply each brake in turn and repeat. If one or the other makes it better or worse it'll be easier to trace.

Andy

[pigafetta]

Worn front sprocket clacking about on the shaft maybe?

Dave B

[johnr]

id say worn front sprocket too!

[tommy]

yeah i would check the gearbox sprocket too....tommy

[Nell]

Thanks for all the response. I will be off on a run tomorrow and check out your suggestions.

[johnr]

just a thought. do you have a chain oiler fitted? its just that my old dr big had a scottoiler and the delivery tube touched the sprocket as it should have done. but wheeling the bike backwards made the tube move slightly out of line and it caught on every link of the chain. result, forward, no noise, backwards, 'click click click'

[Nell]

Same problem again today, no noise when cold, loud clack when hot. After checking all suggestions and finding nothing untoward (G/box sprocket splines are tight on shaft and no chain oiler fitted) the noise seems to be internal from the gearbox area. I ran the bike on the centrestand with rear wheel clear of the ground in first gear. Smooth for a second or two then sharp snatch through the chain accompanied with the loud noise. Smooth again for a couple of seconds then same again, Same result in second and third gears. The chain is fine as is the tension. Strange as the bike runs smooth and well but I will be worried something might seize up or let go.
I have a spare engine so that will go in and then I'll take a look see.
Thanks again for the replies.

[Dick Scratcher]

Are you sure that the bike's 'cleanly' in neutral ?, If you put it in gear, pull the lever in and push it does it still make the noise ?...........................Dick.

[themoudie]

Are you sure that the bike's 'cleanly' in neutral ?, If you put it in gear, pull the lever in and push it does it still make the noise ?...........................Dick.

My thoughts as well Dick, bit o' wear on the selectors!

Bill.

[Nell]

The gear selection seems to be OK as it still makes the same clacking noise with the clutch lever pulled in. All is positive when changing gear and also selecting neutral when stopped.

[Dick Scratcher]

If you can do so, remove the chain from the front sprocket and turn by hand and feel for any roughness and see if the clicking persists. This noise still does sound like a particularly sloppy sprocket on the gearbox output shaft.

[johnr]

have you overtightened your chain in the past? and whilst on about the chain, its not got any tight links in it i assume?

[Nell]

Problem solved. I popped in to my local friendly motorcycle shop and their diagnosis was that the noise was indeed coming from the sprocket / gearbox shaft but was caused by some wear in the rear hub cush drive rubbers transmitting the play to the gearbox output shaft. They had come across this problem before.
The rubbers were changed and all is well. Sorry for any red herrings in the thread but thanks for the interest.

[Dick Scratcher]

To give that problem the rubbers must have been well jiggered (for want of another word), anyway, pleased you've got it sorted and hopefully not too expensive. If the wear in the front sprocket and not on the gearbox output shaft really is excessive it might be worth investing in a new one as they don't cost a fortune. Too much backlash can knacker the shaft and replacing it means an engine re-build, cheap if you can do it yourself, expensive to pay some-one else.
                                                                   Regards................Dick.