This Story Originally Ran In The April 1964 Issue Of Hot Rod Magazine
Kicking off our trail bike review is a real volume package by one of the oldest motorcycle manufacturing firms in the business: Birmingham Small Arms of England. Their newly announced "Trail Bronc" is big news on at least two special counts: this tried and proven 174cc (10 1/2 cubic inch) two-stroke single is over twice the capacity of the average 50 to 80cc trail bike with only a negligible 25 pounds or so additional overall weight (about 200 pounds fueled), and the price is right (within $20 of some of the smaller-engined jobs) at $395.
In order to give the buyer a healthy eight horsepower at this price, BSA has ignored the frills: No chrome (I take it back-the gas cap), no speedometer, front fender, or lights-their original assumption being that such items were costly, heavy, and unnecessary in this critter's natural habitat. Ignition is by a flywheel generator, however (no battery), and if lights are desired, lighting coils are in place for simple attachment to any sort of 6-volt accessory lamps.
Engine and integral 3-speed gearbox are genuine motorcycle components, this design having been refined through nearly a decade of highway and competition use-no guesswork here. The carburetor, too, is the reliable Amal brand with 7/8-inch venturi. Utter simplicity is the keyword of engine layout; two-stroke construction with 61.5mm bore, 58mm stroke, and 7:4 compression. With its huge 80-tooth rear wheel sprocket, this happy little powerplant is a veritable stump-puller at just above idle, even when the going gets deep and sticky, or it can buzz down the road at a neck-snappin' 40 mph. With the 1 3/4-gallon tank topped up with 20:1 gas-oil mix, it should provide all but the most "eager beavers" with a full day in the woods.
Apart from very minor and remediable points of criticism, we found the BSA Trail Bronc most functional and much fun. The frame is simple and very sturdy, being fitted with tube shockspring swinging arm rear suspension and a very basic type of telescopic front fork (coil springs, but without oil damping) that is suitable for the intended speed. The bike is a two-place job with comfortable, davenport-type seat and passenger foot pegs (all foot pegs are made to fold up on impact).
Vital statistics include an overall length of 79 1/2 inches, handlebar width of 27 3/4 inches, height of 40 1/2 inches, wheelbase 51 inches, and 7-inch ground clearance with a 200-pound rider.
True, the gas tank cap should seal a bit better, the side stand should be on the left side so not to invite gas cap seepage when the machine is parked, the kick-starter pedal should fold in out of the way, and a front fender would have helped save face the day we went plowing through the snow, but as we said, these are pretty small points when you've got equipment that's this good.
If you want a lot of engine for the money and can do without the bric-a-brac and the flash of chrome, then the Trail Bronc will make an ideal backwoods companion.