World Superbike Racer
Join Date: Jul 2005
Location: Austin, TX y'all
Thanked 188 Times in 154 Posts
Feedback Score: 12 reviews
Yes, your chain will move around a good bit. You don't want it on the tight side either as you'll destroy it. I would set it on the loose side of the oem specs.
Also chains don't stretch. They are steel. Steel doesn't stretch and if you think it does go buy 1" of steel and tie one end to something that won't move and the other end to a 4 wheeler, bike, etc and try and stretch it. When a chain "stretches" as people say what actually happens is the plates dig into the pins and wear it out thus giving you slop. It's not stretching but the parts are digging into each other and creating slop. You're wearing out your chain and destroying it, not stretching it.
As your suspension in the rear compresses and raises the slack in the chain will change thus making it look like it's flopping up and down. If you tighten your chain too much your suspension can't work as it compresses and tightens the chain you'll be pulling on the front sprocket very hard. You don't want a chain too loose, but if you have to be on the loose side or the tight side, you would rather is be on the loose side then the tight side.
Set it on the loose side of the specs and you'll be fine.