Pinewood Derby Stories and Photos from Maximum Velocity
I have been spending a lot of time lately looking at BSA wheels (how boring you say). Yes, a bit, and also hard on the eyes. But I am finding some interesting information.
The BSA wheels are made from 16 different molds - numbered from 1 to 18, skipping 6 and 7. Each mold imparts its own characteristics into the wheels it forms. For example, mold 17 creates an extra wide serration; mold 13 creates a flaw on the tread side of the wheel bore; and molds 8 and 11 create undersized wheel bores.
But most importantly, some of the molds produce better wheels from a 'roundness' and symmetrical viewpoint. If given the opportunity I recommend using wheel numbers 2, 3, 5, 12, or 17. These wheels are the most round and most true, so they should produce the best results on the track.