I picked this method up from a fellow racer here in Southern Ontario.
1. Got to Wal-mart & pick up some small split shot sinkers.
2. Cut them in 1/2 with a pair of side cutters.
3. Take a hammer and pound the little "domes" into "pancakes".
4. Secure to wheels by covering them over with a layer of real (foil) duct sealing tape.
The beauty of this method is that you can cut down the little "pancakes" with an exacto blade to get just the right weight.....
Narly1