Chassis.
3in x 1in (75 x 25mm) 16 gauge (1.5mm) ERW steel box.

Wheelbase.
Max 70.8in. (1800mm). Recommended 66in (1676mm) centre of wheel to centre of wheel.

Track Width.
Max 38in. (965mm) Centre of tread to Centre of tread or 39.3in (1000mm) from out side to out side of tyre.

Engine.
Honda GX200 or clone. (6.5hp)  Stock or Stage 1 upgrade.

Transmission.
Kart centrifugal clutch or torque converter.

Front Suspension.
Dropped axles with semi-elliptic springs, straight axles with quarter-elliptic springs or straight axle with a single transverse spring.

Rear Axle.
Live axle (25mm) or Peerless differential axle, ridget mounted.

Wheels.
Honda C90, Honda ANF125 or pit bike . 17in wire spoke.

Body.
Based on pre WW2 cars. Materials: plywood, aluminium or fiberglass.

Full technical specifications can be found here. http://forum.cyclekartsgb.com/index.php?action=ezportal;sa=page;p=2
Builders guide can be found here. https://cyclekartsgb.createaforum.com/tech-forum/a-'potential'-builders-guide/

yea, this is a bit confusing... the numbers here are different to the existing spec rules. max track width of 1000mm not 965mm (although measured from a different place, so they equate to roughly the same), and max wheelbase of 1800mm not 1676mm.

Chris, without your link I was not aware there was a rules section. Not the easiest thing to find, or is that just me ?
Not trying to rewrite the rules just making it easier to find.
Take my post down if needed.