awryt guys quick question should my nc24 sprocket holder have any fore and aft play . also im getting a grinding and jumping feeling when riding at slow speeds any ideas. cheers

NO!

Get it apart and check out the bearings. Probably cheaper to get a decent used item in the marketplace.

If it seizes you're in trouble, be careful.

You mean the cush drive? Then yes it should, theres rubber blocks inside to take up the lash from the chain.

You can turn it left and right a little with the chain off.

It shouldn't move in an out.

Take the chain off to test but if you hold it at 3 and 9 oclock you shouldn't be able to pivot it, same with 12/6 o clock.

But you can rotate due to cush drive.

Grinding noise sounds like knackered / badly ajdusted chain

Shouldn't have freeplay. Should be able to move it, but it should take a bit of force to do so. Maybe the bearing is dead, maybe the rubbers want packing out. If the rubbers wear out, it'll let the bearing die in double time.