Knocking at speed

[Revilo]

Hi all,

Got a 2005 Tiger 955i with 40k miles on the clock. I've not had it long and love it but I've noticed a noise from *down below*!

The noise is a sort of rumbling knocking vibration that begins around 45mph and worsens till 55mph when it either levels off or drops a bit (I can't tell as wind and road noise also drowns it out over 60mph).

It seems to be coming from the left hand side, maybe the chain drive sprocket area.

I wondered at first if it was my luggage knocking (I usually have a fly fishing rod in a tube strapped to that side) as that what it sounds like: a rather random knocking noise. But it's still there with the flapping baggage gone.

The only thing that worries me is that I accidentally over-tightened the chain (did it while off the bike and forgot to factor in any slack for my 285lbs weight and suspension travel :-( ). I ride it for a couple of days like that with a v tight chain and hope I haven't done any damage.

The noise is speed not revs related and is worrying me.

Any ideas? Or is this normal? Performance, handing, fuel use etc all seem unaffected and its riding fine. But I know knocking noises can be bad news -- and expensive

Thanks

[SteveFord]

Retorque the countershaft sprocket nut and see if that does it.

[Revilo]

I think I'll get a new chain and two new sprockets

Thanks!

[metalguru]

Check the rubbing strip fitted to the front of the swing arm, it is possibly worn out at that miles.
When fitting the new chain/sprockets, if you can tie up the swing arm so it is straight and not sloping down from the engine sprocket end. This can be acheived with a ratchet strap or similar, then set chain slack and check for any tight spots. This is safest way to get adjustment correct as it is critical on these bikes.