Chain slack/play while riding.

I have a 1977 KZ650B1 I've been restoring. Had it out for a few road tests. It runs new sprockets (16T front, 42T rear) and a new chain.

I have the chain slack set at approximately 1/2" - 3/4" when the bike is on the center stand. It drives and shifts smoothly, but I've noticed in the late evenings when I can see my shadow beside me on the road there is a noticeable amount of up/down movement of the drive chain while I'm in motion. I don't feel any vibrations or hear bad noises. Is it normal for a chain to run this way?

When I spin the rear tire while the bike is parked on the center stand I can visibly see a bit of up/down play in the chain as it rolls. I have a rear wheel alignment tool so I have checked and everything is lined up as it should be for the chain/sprockets...

Hey barquirt,
Yes that all sounds normal. If your chain was worn it would also be normal for there to be more slack in different sections of the chain. Adjust your chain while it's at the tightest portion.

More slack will be felt as gear lash. A too tight a chain will make a whining sound and will overly stress the whole system.

KZCSI

i read somewhere over the last few days that you should set the chain slack with a friend sitting on the bike to weigh it down, for exactly the reason you mention.

I've heard that too duncan but according to the factory manual, the bike should be on the center stand when adjusting. The slack your allowing in the chain is for the weight of bike and rider.