Mix and match

In the motorcycle world there are any number of reasons to create a special with components from various sources. These reasons range from ‘couldn’t afford a catalogued machine’ to ‘the standard offerings weren’t right’ and often include ‘had a load of bits’ and ‘sheer bloody-mindedness’, to give just four examples. Some such specials or ‘bitzas’ are more common in one sphere of the sporting world than others, for instance the combination of Triumph engine in a Norton frame is evocative of the café racer scene, while slipping a Triumph engine into a BSA frame is much more common in the scrambles world. The resulting TriBSA was and is arguably a better clubman machine than the BSA Gold Star that often donated the rolling chassis.

Now before the Gold Star Owners’ Club gangs up on me, I have to say the Goldie is a superb machine – but in order for it to produce the best it can do, a comprehensive maintenance schedule has to be followed, as it is pretty much a race engine. The problem was, not all club-level riders could afford the maintenance and parts that had to be replaced or rebuilt after a certain number of hours. There was a tendency to think ‘we’ll get another meeting out of it…’ and all of a sudden there’s an engine-shaped hole where the engine used to be.

Luckily Triumph’s versatile twin engine was relatively cheap and much more easily maintained by the enthusiast watching the pennies, and it wasn’t difficult to fit into the BSA frame. Those who had the Gold Star chassis got quite a high spec, but there was no real need to go that far as even the B31/B33 and the later swinging arm A7/A10 chassis was an all-welded one to the same dimensions as the Goldie. Okay, so it had a few more brackets and whatnot, but hacksaws and files sorted that out and the twin frame didn’t have the oil pump kink in the lower frame rail – but with a Triumph engine, it didn’t need it.

Read more in the Winter issue (No.49) of CDB – out now!