This section is designed to give you a guideline to what the rules are trying to say. This hopefuly should make it easier for racers to determine if this is the right series for them, and allow spectators to see why the Thunderbike championship is so competative and interesting.

The whole premis behind the thunderbike class is a power to weight ratio. Newton's 2nd law states that Acceleration = Force ÷ Mass . The force in the case of a motorbike is the force at the rear wheel. The mass is the weight of the bike. So should we be using a torque to weight ratio? Well by definition BHP = torque x revs. So how about a graph to give some idea;

If that doesnt help you find your target weight here is something a little more interactive. Either enter a maximum expected power, or a minumum expected weight, and it will calculate how light, or how powerfull you can be :-

A maximum power of A minimum weight of   bhp  would give a minimum weight  of 181.4Kg

The next big area is designed to weedle out the bikes that would only fit into the above limit by having large weights put on them. The engine specifications, and in some cases the year of manufacture, are used to dictate which bikes are eligable. There are a LOT of interesting bikes out there which effectivly have no where to race at a top level sereis because they do not fit the modern 1000 and 600 fours classes, we hope this series will rectify this.

There is little else in the rules, which means that the engineers can have some fun and create proper race only motorcycles. You have to keep the original intake system (carbs, or injection). However the bore and stroke can be changed so long as it still fits within the rules. The engine mapping can be modyfied and weight can be reduced, wheels changed, fairings ripped appart and painted blue. Anything you want to do.

This is an enineering and ingenuity class for those that want to go that way. As a spectator please be aware most entrants will have put a LOT of effort to be on the grid using their own skills.

Footnote:These are not rules. If you want to see the nitty gritty, please go here. If you are in doubt about any part of the rules, or just want to know more than go to the contacts page here and email one of the thunderbikes team.