I adjusted my chain myself for the first time yesterday. Its a pretty straight forward thing to do but today i realised that somehting wasnt quite right. I adjusted it with the bike on its side stand and on level ground. The book says 30-40mm of slack in the chain which is exactly how i sdjusted it. Problem is that when im on the bike, just sitting on it and taking up some of the suspension travel, the chain is wayyyyy too tight. She wont even budge a few mm. What would cause this? The wheel is tracking straight, according to the indicators on the swingarm. Bike rides fine but am a bit worried about how tight it is when im on the bike. soon as i jump off and check the chain, its back to the right tension again? Any ideas?