http://www.bikeforums.net/showthread...ightened-chain

As discussed there, you should have the chain literally .25mm away from having ANY tension.

Try this: index fingers on the axle nuts, thumbs on the track ends. Press together and spin the nuts tight keeping the thumbs on the track end. Make sure the axle doesn't move. Tighten the drive side first. Align wheel and tighten the non drive side. Done.

Ride.