| Anybody fancy a go at this..... (Racing)
THUNDERBIKE - Thunderbike machines, except single cylinder machines, are based upon production models, sold by manufacturers and their dealers in the UK for street use. Proof of compliance rests with the competitor entering the motorcycle. Single cylinder machines are exempt from production and street use requirements. Single cylinder
2 stroke GP road race machines are not allowed in this class. All machines must have unaltered VIN numbers.
NOTE: Ducati 748/749 Series machines are excluded from this class.
1. Production machines not sold by manufacturers and their dealers for street use in UK via normal commercial channels may be approved on an individual basis. FORMULA Thunderbike will maintain a list of non-standard approved models and that list will be available at each event from the Race Director/Referee.
2. All machines must meet the equipment standards of Section 5, as well as the following:
A. Frame, cylinder head(s) and engine cases must be from the same production model
motorcycle. Single cylinder motorcycles may use any frame and engine.
B. The frame must be as originally supplied by the manufacturer on the approved
model. Strengthening gussets or tubes may be added. Only brackets or tubes not
supporting suspension, engine, or drive line components may be removed. Swing
arms may be modified or replaced and rear shocks may be replaced or relocated.
Single cylinder motorcycles are excluded from this restriction.
C. Reducing engine size of machines from stock displacement to meet Thunder class
displacement limits is not allowed.
D. Fairings that meet the requirements of Section 5 (Safety regs) may be used.
E. Liquid cooling is not allowed unless original equipment on the model being used.
F. Original type of induction system must be retained. If a machine originally was sold
with fuel injection, then it must remain fuel injected. If the machine originally
came with carburetors, then it must use carburetors, however they need not be the
original type or size.
3- Thunderbike Class displacement limits are absolute and are set as follows:
THUNDERBIKE
Single cylinder, Unlimited displacement
Twin cylinder, air cooled, Unlimited displacement
Twin cylinder, liquid cooled, 3 or less valves per cylinder, Unlimited displacement
Twin cylinder, liquid cooled, 4 valve per cylinder, up to 750cc
Three cylinder, non-fuel injected, up to 1200cc
Four cylinder, air-cooled, up to 1200cc
Four cylinder, liquid cooled, 1990 to 1992 model year, up to 650cc
Four cylinder, liquid cooled (oil or water), pre-1990 model year, up to 860cc
All air-cooled, 2-valve, unlimited displacement  | 
15-Nov-2005, 17:30 
ChrisBushell
skidlids
Linear Mode
