PRO Class

Car Body ( the wooden/material structure that holds the weight, axles and other add ons)/ Total Car Dimensions

Wheel Base : Any as long as wheels do not exceed the 7″ total length requirement
Total Car Height : Not to exceed 3″ inches…
Total Car Length : Not to exceed 7″ inches…
Total Car Width : Not to exceed 2-3/4″ inches…
Total Car Weight : Not to exceed 5.0 ounces (+.04) or 143 grams even measured on 1/10th digital scale

Additional materials maybe added as long as they meet the rules

4 Axles & Wheels must be installed to the side of the car body directly across from one another / No more than a 45 degree angle. Rear wheels cannot be reversed.

Track Center Rail Height : 1/4″ inch ( 7mm ) *
Track Center Rail Width : 1 5/8″ inches (4.2 cm) *

* Wheels must clear the outside to outside center rail width measurement

Axles

a. Minimum diameter .084
b. Axles must have a nail head

Wheels (No bearings)

BSA, Maximum Velocity, Awana, Pinecar

a. May be CnCed, lathed, polished and/or sanded to true the edge of tread, surface and circumference
b. The tread / contact surface must remain flat and parallel to the bore as humanly possible
c. No Angling, Reshaping, Canting, Round Crowning, Tapering, H-ing, V-ing, Dishing, the outside of the wheels and/or tread surface
d. Lettering must remain visible on the inside and outside of the wheel. In the case of a wheel that has no lettering on the outside the original shape must remain.  A wheel cannot be machined flat on the outside sidewall.
e. Wheel covers may be used only if entire wheel is visible
f. 7.50mm Minimum Tread Width
g. Wheels have no weight restriction as long as they meet the above requirements.