The chassis is a spaceframe fabricated from 35 metres of 12.5mm diameter mild steel tube, all joints are nickel-bronze brazed.

» Weight is approx 12.75 Kg (bare frame without any mounting brackets)

Massive tomes exist to explain spaceframes but briefly:
A spaceframe is a collection of triangles in 3 dimensions, all members are straight and loaded in compression or tension only.
Properly designed spaceframes are extremely light and exhibit superior torsional rigidity, a prime requirement for good handling.
The vehicle has admirably survived much abuse as a paddock basher.

Real world compromises usually manage to insinuate themselves into any design.
Most serious here is the "square" unbraced cockpit opening, others are offset suspension mounting tabs, hand & footbrake mountings and the "bent" (but very rigid) horizontal member at the back of the seat.
(this last design constraint was imposed because the current driver is substantially taller than the original "Mileage Marathon" jockey)

» Wheels are standard Honda postie bike and weigh 5kg front & 7.5kg rear
» Tyres are 2.25x17 front & 2.75x17 rear