Chain adjuster jammed

MY son bought a VFR as his 1st bike and I've been teaching him how to do maintenance on it.
We just replaced the chain and sprockets and now the chain adjuster cog won't rotate
The bike was moved around in the garage, possibly with the chain adjuster clamp bolt loose
Now, we've tried to move the cog wheel both ways without success.

What went wrong and how do we fix this?

 

Never heard of one seizing ... if it's truly seized, haul out your service manual (get one if you don't have it) and take the mechanism out of the swing arm to see what's going on.

The only cure for anything that is seized is to try and get it apart so you can inspect and lubricate it.

 

Was the pinch bolt backed off? Try a shot of chain lube or even kerosene on the mechanism first before tearing it down. The pin spanner can also be tapped with a hammer. Tapped being the byword.

Gentle use of a drift instead of the pin spanner is good sometimes too.

 

Mine was the same when I got it.I'd bet the hub isn't seized in the swingarm its the caliper bracket seized to the hub.You 've got to strip it all apart starting with the big nut.A tip for you , heat everything that won't budge with a hot air gun and good luck with the giant circlip.You need to beg,borrow,steal the right tool there.Then when it's all cleaned hit it all with the copper grease. 2years on and mines fine still.