I got my kid a used MCS Holeshot for racing. It looks to be in decent shape, but there's something I don't understand going on with the rear wheel/freewheel.
When it's in a bike stand and coasting/freewheeling I notice the chain "moves," it basically gets tighter and looser. I don't understand how that's possible if everything is perfectly round, but it's obviously happening. I looked at another, older bike and I see it doing the same thing, but not quite as much.
Is there a word to describe this? Is it more common on lower-end bikes or do all bikes do it? Is it anything to worry about?
The rear hub doesn't sound great when it's coasting on the stand, it sounds kind of crunchy, but it spins pretty smoothly.
Thanks for any tips you can send my way.
-Mike