If you tighten that big bolt it would tighten the crank. Some have a dust cap, which that may be with the crank bolt underneath which would need an appropriately sized socket.

More than likely you will need a crank puller to remove the crank.

http://www.parktool.com/repair/byreg...ageField2.y=14

Park tools knows what's up. Figure out what kind of crank/BB interface you have.

It sounds to me, however, like your chain is getting a bit loose if it only happens when your trackstanding. Do you feel a little hitch if you go from pedalling to skid/brake with your legs? Try pulling your wheel back in the dropouts to tighten your chain up a bit and see how it feels.