Rearend vibration?

[GKG-MO]

Well I got the bike put all the way back together last week and it looks and rides awesome!

BUUUT I have a vibration in the rearend! It comes and goes and has something to do with the drive train. Its not an out of balance wheel or anything like that because I get it takeing off a lot and even at very low speeds. It also seems to happen more in the low end of the gears like when I need to go down a gear and the bike is bogging a little. If I crank on it and open it up it stops. I looked at the chain while it was doing it and its jumping up and down a good bit. It almost feels like the swingarm is jumping up and down a little. It hasent stopped me from riding it but maybe I need to park it till I figure this out.

I hardtailed the rear and did a Harley rear wheel swap so it probably has something to do with that. The wheel seems to be tracking good and turns easily. A local bike shop took a look at it and he seemed to think that the front and rear sprockets weren't on the same plain, so I checked it with a string and a ruler and it looks good. I don't think a little off would cause this bad a vibration anyway.

Anybody got an idea what it might be? Is it something that you just feel when you hardtail? This is the first hardtail I've ever riden so I have nothing to compair it to.

Thanks in advance for your help guys!

[SHADOW 1100T]

What is it, a shaft or chain

[casper48]

Make sure that the bushings for the swing arm are in good condition. Make sure that your chain is not worn out. also it is very important that two sprockets are aligned. using a string is not the best method. use a ruler to make sure of that. make sure that the chain has the right amount of tension.