Racing Spool

In days gone by, you could make a racing spool from an empty thread spool, two nails, a bead and a rubber band. Nowadays, most thread spools are made from plastic and not suitable for such purposes. Besides, it really helps to use rubber bands for tread and it can be hard to keep them on the spool.
There are two models here: one a quick adaptation from the knitting spool, the other with modified rims for improved traction (though you'll still want rubber bands for tread).
So pick your driver rubber band, build your racer and go!