These are the rules for Racing your Bantam.

Bantams are raced as a subsection of the Vintage Motorcycle Club racing section currently there are about 20 racing, tracks raced at Mallory, Lydden, Cadwell, Snetterton, Darley Moor, Anglesey, pasted in below are last years rules some very minor wording changes have been made to these for 2002, they are still good enough to use to build one.

I have a tuning manual that I print to order so it has all current changes I am in the process of trying to make it web based.

125 Formula Bantam
1. CAPACITY: All machines will be of 125cc (+ oversize pistons to 2mm), maximum.
2. ENGINE: Modifications to engine or gearbox are allowed, provided that conditions (a) to (e) below are met: -
(a) Bantam crankcases must be used.
(b) Disc valve induction is prohibited.
(c) Pressurised fuel injection is prohibited.
(d) Only BSA close ratio and BSA normal ratios gears or exact copies
(e.g. AA Snell ) to be used. Maximum number of gears: Three.
(e) Only standard cylinder barrel to be used, but may be modified.
(Alloy Todd and BTW copies deemed to be standard but to remain external unchanged )

3. FRAME: Must retain Bantam main loop, but may be modified.
4. WHEELS: Must retain wire-spoked wheels.
5. FORKS: No restrictions
6. BRAKES: No restrictions
7. TANK: Must be mounted in normal position on machine.
8. FUEL: Petrol only.
ACU standing regulations for road racing machines apply (where applicable).


175 Bantam Formula
1. CAPACITY: All machines will be of 190cc capacity maximum
2. ENGINE: Modifications to engine or gearbox are allowed, provided that conditions (a) to (j) below are met: -
(a) Bantam crankcases must be used, and remain externally unchanged
(b) Disc valve induction is prohibited.
(c) Pressurised fuel injection is prohibited.
(d) Only BSA close ratio and BSA normal ratios gears or exact copies
(e.g. AA Snell ) to be used. Maximum number of gears: three if close ratio, and four if normal road ratios
(e) Only standard cylinder barrel to be used, but may be modified.
(Alloy Todd and BTW copies deemed to be standard but to remain external unchanged )
(f) Stroke to remain standard (58mm)
(g) Standard Bantam port layout is mandatory, i.e. one exhaust port, two transfers and one inlet
(h) Exhaust power valves prohibited.
(I) Water-cooling prohibited
(j) Ignition to be fixed timing. (i.e. not advancing or retarding type)
3. FRAME: Must retain Bantam main loop, but may be modified.
4. WHEELS: Must retain wire-spoked wheels.
5. FORKS: No restrictions
6. BRAKES: Front Brake: No restrictions Rear Brake: Must retain Bantam hub (may be modified)
7. ???
8. TANK: Must be mounted in normal position on machine.
9. FUEL: Petrol only.
10. CARBURETTOR: Size: 38mm maximum, circular bore only.
11. ACU standing regulations for road racing machines apply (where applicable).

Any "125" rider winning the Bantam Championship must change 'up' to a 175 engine thereafter.