Clonk and whirr

2 issues in one thread, but not sure if they are related.

1) Whirr. I have noticed over the last couple of months a whirring sound, kind of like a bearing running not so smooth, but not grinding. Checked wheels and they don't wobble about, so don't think wheel bearings. Local mechanic said my brakes were now so gunked up that a clean would not do, a full rebuild required, it was probably them just binding making the noise. I dutifully took all apart, cleaned (horrible state they were in), installed new seals, pads and new rear pistons. Brakes now great, whirr remains.

2) Clonk. gear change on 1st, 2nd 3rd especially seems to have got more clonky recently, no better way to describe it. Had oil change at same time as getting advice on brakes, and it seemed to help a bit. But sometimes neutral to first, or changing down from 3rd or 2nd, it really clonks into gear. Put new clutch cable on a couple of months ago, and adjusted it per the manual.

I am starting to wonder whether something has worn or is out of adjustment in the gearbox, and is making both the whirr and causing the lumpy shifts? Where's a good place to start checking and how? Am I about to experience a complete gear box destruction and I should be looking to trade it in? Any other thoughts?

To finally complicate things, the 'whirr' seems to go away if I ride along one of those long painted arrows. Had new Avon STs in March, surely it can't be tyre roar making the noise? Oh, '99 naked btw.

Cheers.

[yorkie_chris]

Is the whirr road speed matched or engine speed?

Clonk is probably clutch adjustment or chain issue.

Both issues could be connected to chain.

TBH the whirr seems to be pretty constant in pitch, goes below about 5mph, and above about 45 can't hear it for wind noise. Chain recently (and regularly) checked, lubed and adjusted to recommended 20-30mm slack. I had wondered whether it was the noise of the chain rubbing on the plastic swing arm guard, but assume when sat on bike the chain should actually be clear of that? I have not measured the chain for stretch, but when adjusted it only pulls from the rear sprocket by less than 5mm or so, therefore I assume it is probably ok?

Possibly clutch adjustment then. Adjusted at lever per spec, and looks like the angles at the clutch end are as they should be from the manual, but I not experienced enough with the bike to know for sure.

Did you ever suss this as I have exactly the same noise/problem (if it is a problem)

[MJC-DEV]

An over-tight chain can produce a whirr sound - 20-30mm is a little on the low side unless you've confirmed it doesn't tighten up when you sit on it. Started to check mine after the last Mega-Thread and it does indeed tighten up for my weight.

The whirr sounds like the chain. After replacing the OEM front sprocket with one without the rubber cushion I have noticed an increase in chain noise.
Didn't help that my Scottoiler had run out and the chain was starting to run dry.

If the chain is well lubed you may have a tight spot in it.
Rotate your wheel and see if the chain rises at a specific point, if it does you should re-adjust your chain whilst it's on the tight spot.