Drive Chain Slack

Hello Boys and Girls,

I'm just wondering how tight my chain should be?

As Ive noticed that some of the track only bikes dont seem to have as much tension as standard Road bikes?

zx10r manual
Chain Slack/ play
Standard: 30 ∼ 40 mm (1.2 ∼ 1.6 in.)

Cheers
Keith

With you or a mate sitting on the bike so it is weighted go for 20 - 30mm play & rotate the chain to check in a few positions as you will probably have a tight spot in the chain, remember that when you do up the rear axel the chain might tighten a slight bit more so you will have to compensate for this when adjusting.
With race bikes because track surface tends to be smoother than the road you could probably get away with a bit more slack, for 520 conversions the down side is the chain will have to be adjusted more frequently as it will stretch quicker than a heavyweight chain.

I always get harassed for it, but I always run mine quite loose on the tracky in particular. I'm a fat bastard and I'd much rather not risk binding up the chain. If you think chains need to be tight to perform well have a look at a MotoGP bike.

Would say he has about 30mm + slack,
I reckon that under drive a chain tends to look slacker than when standing, as it moves with the suspension ... just an observation & I got a close look last track day watching a whole session with the flaggie at Turn six

Also consider that your bike squats (or should) alot more coming out of corners on the track than on the road as your generally alot harder on the gas (or again should be). Because of this there needs to be more free play than what the manual may say. Also the tighter it is the more resistant it creates which sacrifices HP

dead right Rob - and that is because under power, the top run is fully tight, so *all* the slack is in the bottom run.......whereas when you check the chain slack with the bike sitting on its sidestand, or even when you check it with someone sitting on the bike in the attack position, the top run has a small amount of play in it......its not much, but it is there.