thanks for the suggestion as i didn't look in chpt 1. i found the following (from
https://s3.amazonaws.com/USACWeb/for...k-Chapter1.pdf)
1I. Bicycles
1I1. Bicycles used in competition must be propelled solely by
the rider's legs and shall have the following characteristics:
(a) Dimensions. Bicycles may be no more than 2 meters
long and 75 cm wide, except that tandems may be up to 3
meters long
(b) There may be no protective shield, fairing, or other
device on any part of the bicycle, which has the effect of
reducing air resistance except that spoke covers may be
used.
(c) Wheels may be made with spokes or solid construction.
No wheel may contain special mechanisms to store and
release energy
Except it doesn't say if this would apply to mass start bikes as well