Rules? We don't need no stinking rules!
As a racing class, Buttboard was perfect to become the "Spec Class" for Street Luge, where everyone has equivalent equipment and what is being tested is just the rider's skill. If you are riding for fun you can fudge on the specs below, but why bother?
At the Hot Heels competitions in Austria if too many modifications were made to a competitor's skateboard it was booted into the Street Luge class. The modern rules were codified in 1998 to numerically capture the design limits, so people could easily create Buttboards around the world.
Each racing organization has played with minor tweaks to the text below, but essentially the rules have been stable for a decade.
CLASSIC BOARD SPECIFICATIONS
(Buttboard)
The BASIC PREMISE is that any rider
should be able to put together a competitive board
from skateboard shop supplies for about $200
complete. A rider may spend more on a board if they
wish, however, advancements which require a higher
investment to be competitive, will be banned.
A. DECK: Must be made of wood. The
deck may have molded features such as a kicktail,
but must be one piece. No dropped boards. It may be
any shape within the size limits. Nothing may be
added to the deck except for the following:
1. Foam padding to the top.
2. Non aerodynamic stiffeners to the
bottom.
3. Skateboard-type grip rails
underneath.
B. WEIGHT: The complete board must
not exceed seven kilograms (15 lbs).
C. LENGTH: One hundred twenty-five
centimeters (125cm / 48") maximum.
D. WIDTH: Three hundred five
millimeters (305mm / 12") maximum.
E. TRUCKS: The trucks must be lean
steer activated. They must be commercially
available* skateboard trucks. Trucks may have a
rolling axle. They
must not exceed three hundred five millimeters
(305mm / 12") wide, as measured from the outside
edge of the axles. The board must use exactly two
(2) trucks.
F. GROUND CLEARANCE: No portion of the board may be lower than the top of the wheels (70 mm) plus an additional 10 mm clearance. (Minimal ground clearance is therefore 80 mm or 3 1/8"). This does not apply to the trucks themselves, but does include any portion of the deck, grip rails, stiffeners, etc.
G. BEARINGS: Standard steel 608
skateboard bearings only. No ceramic, Mini-mizers,
9 balls or other high performance or exotic bearing
types.
H. WHEELS: The board must use exactly four (4)
70 mm (or smaller) skateboard wheels
only. They must be commercially
available*.
*Commercially
available means the product must have been
distributed to at least 24 people outside the
company.