Bantam v Kwak1300

"Muck pleasures himself with root vegetables"

Doesn't mean it's so.

Well, it might be, I don't know one way or the other.

To my eye, the 125 bantam cylinder is angled forward more, and the shock
on the racer is about 3 times as long as the stock item.

When I've eyeballed road race bantams in the pits I've seen they
generally use D7 crankcases which is one of the 175cc models. Whether
the 125cc cylinder drops straight on or not I'm unsure, but it seems the
rules allow some deviation from what came out of the factory. In fact a
bit of searching the web came up with these rules:

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).

As Tog says. I wouldn't know a Bantam is one rode over my foot. :)

It certainly looks like a Bantam engine to me, though it has obviously
been tuned, so could have anything inside it, the barrels on those were
pretty big, so can be bored out a long way.
The exhaust pipe is the big giveaway as to it being a bantam engine.
The race bikes were quite good in their day, BSA made a pretty good
frame, add decent forks and shocks, and they handled as well as anything
out there.
Alan.