Hi, the book says around 50mm slack on the chain. This is about double what I normally have on multi cylinder bikes. Happy to leave it at 50mm but I notice the chain is in contact with plastic part on top of swingarm?
Andrew

Hi there, for a start which model bike?

These bikes have quite abit of suspension travel and if you adjust the chain too tight it will knock out the cush drive and bearings, could even snap the chain.........................and yes I do know the hard way!
Keep to the slack stated in the manual, I for one have kept mine even a bit more on the Tenere.

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+1 The slack side or 50mm is best, especially if you take a pillion or load up regularly. A tight chain is bad news for your gearbox in the long run.

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The amount of slack depends on 1) the amount of suspension travel, and 2) the relative positions of the gearbox sprocket centre and the swingarm pivot. In theory, a bike with the swingarm pivot concentric with the sprocket could run with almost no chain slack. But the manufacturers have done the maths and I would go with what they say.

On the XTR it specifies 40-55 mm (from memory)> I set mine to 45 mm and it is fine. The chain rests on the slider when the bike is unloaded, but as soon as there is a load on the suspension it is clear.

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If you really want to be sure you have just the right amount of chain slack then lift the bike off the ground and disconnect the shock from the swing-arm by removing the dog bone links - and then you can easily lift the back wheel all the way through its range. This way you can ensure that at the tightest point of the arc the chain is not pinging tight.

I raised my bike with shorter dog bones, which exacerbates the amount of chain slack when my bike is unweighted - but swinging the rear wheel thru its arc shows that it needs that extra slack!

Its an XTZ, actually when I measured the slack (which seemed excessive) it was only around 35mm so I will try it a little more. Thanks for responses.