Slight whine from new final drive

[ThunderGuts]

So went out for a ride yesterday, about 30 miles, on my fresh sprockets and chain install; thing is, there's a slight whine audible from around 20mph - 50mph (linked to road speed and pulling the clutch has no effect). Really quite faint but it is noticeable (the bike is pretty quiet otherwise); definitely wasn't there before though. Tried going up to similar gears and revs with the bike on the centre stand but couldn't replicate the noise. Bizarrely the noise is more audible with the visor down than up, which makes me think it's being transmitted through the pegs/frame than me hearing it through the air, which could also explain why I couldn't replicate it on the centre stand. Rode through a tunnel too and no difference to noise volume which reinforces the transmitted noise theory I think too.

So, I've checked the tension and we're good, axle is torqued correctly (and I've removed the wheel numerous times before and reinstalled to the same factory torque settings so I don't see that being the issue), alignment is good (measured it axle centre to swingarm pivot centre, less than 1mm difference side to side), sprockets are installed the right way around and the chain and sprockets are all the right size (520).

Things that have changed; sprockets and chain are not the same make/model (previously Kawasaki front sprocket, unknown rear, DID chain, now JT sprockets and chain), front sprocket used to be a rubber cushioned one, now it's a plain steel one.

Tried googling on this and find all sorts of conflicting information, including suggestions the chain is too tight/loose, that it's normal, that it's down to the sprocket change etc etc

It seems unlikely to me I've suddenly got a failing bearing on my hands, it would be quite a coincidence to happen at the same time as a chain/sprocket change, which makes me home in what's changed.

Does anyone have any ideas?

Cheers
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TG.

[Grubscrew]

I’d go for either of the wheel bearings or even the carrier bearing.
Reason: there may have been different tension on chain through to sprocket through to wheel via bearings.
Strangely you can go for years without touching the running geometry and by having released it , which I might add would have had a different torque value to when it was reassembled through settlement to a greater or lesser degree.
Have a peek, if you’re careful you can infact prize out one side of a bearing seal and inspect the ball bearings within. It’ll go back easily enough, ( a wipe of grease ).
Keep us posted.
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FJR1300/CBR1000F

[ThunderGuts]

[Riejufixing]

[kgm]

The stock sprocket was probably rubber backed for damping which reduces noise. The new one won't be, so it's possible there the only reason.

But check wheel bearings anyway.

[ThunderGuts]

[BusterGonads]

You've confirmed that chain tension and alignment are correct. Given that, the thing that most sticks out is that the front sprocket used to be rubber mounted and the new one isn't. This will certainly cause mechanical noise transmission to change. If it is really a concern for you, try temporarily reinstating the rubber mounted front sprocket to test if that is the cause. You won't need to ride far to test for the issue, so no need to worry about damage to new chain.
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2016 Triumph Street Twin; 2000 Honda CG125; 1997 Honda Nighthawk CB250

[MCN]

Did you clean the old sillycunt lubricunt off the rubber final drive elements and re-lube with fresh sillycunt lubricunt?

It is a maintenance point. And they'll bed-in better coz they wont be so grabby.
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Disclaimer: The comments above may be predicted text and not necessarily the opinion of MCN.

[ThunderGuts]

I think the conclusion is it's sprocket noise . . . I'm happy everything else seems OK, so I don't think (!!) it's going to fall apart on me at 70mph. I'll ride it and see how it goes.

More extensive googling suggests that I'm not the only one to experience this, with some even binning the plain sprocket and buying a cushioned one.
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TG.

[Scythe]