BSA C11 Deluxe 1939 Restoration

The little bikes are quite easy to restore as there is not an inordinate amount of chroming involved, most of the paint work is black including the wheel rims and spokes.

The BSA C11 of 1939 vintage is not a very common beast and some spares are hard to come by, like the slightly upswept exhaust pipe, headlight brackets, toolbox, hand bars, seat fittings, Cush drive and clutch parts. Girder fork parts can be awkward to find as well. As the customer wasn’t too critical about originality, several aftermarket parts were procured by the customers from suppliers purporting that the parts covered the year of 1939.

the engine and gearbox was a piece of piss to restore as they are so mechanically simple and loads of internal parts are interchangeable with so many BSA models of that year and even 20 years later.

The first bugbear was the sprung rider’s seat, I told the customer that he needed to replace the seat cover, and he said the aftermarket cover and the aftermarket spring seat frame were not much more then buying the cover itself to cover the original frame.

After receiving the new part it was found that there were no seat pivot brackets and nothing to fit the seat springs to the seat frame and the main frame. 4 ½ hours later we had it fitted this equates to f140 + VAT for the night mare .I think it would have been prudent to have taken my advice to get a new seat cover.

The original handlebars where manufactured in a totally unorthodox manner. The top yoke had no caps to hold the bars on, the yoke had a hole drilled in both ends necessitating two halves, IE: one has to cut the handlebars in half and cut ends into there respective holes. An area of the cut bars had to be scalloped to clear the pinch bolts, “what a crap idea”.

The clutch corks were impossible to source, I used to buy them by the hundreds in the early 1980s, “not now”. I have the press tools for cutting corks. As we used to manufacture them for Hamrax motors, an old batch was trimmed to fit the C11 clutch plates. The head light brackets from aftermarket suppliers were miles out of tolerance so I sent them back and made some new ones from round tube pressed flat and drilled on each end.

During three house moves the C11 had been dismantled in an attempt to restore her, vital parts that would be costly to replicate were lost this includes the clutch centre and some Cush drive parts. A new clutch centre was supplied by the owner and it was found that the tapered centre was different. The clutch centre was common to several models of BSA of the same year. If you stray from the same year of manufacture you may find that things have been modified or changed throughout the different models. The clutch centre was common to the C10, M20, M21 and the B29 of 1939. The Cush drive parts were all common to the models mentioned above as well as the BSA C12.

When ordering parts make sure that the model is tied up with the year of manufacture. Russel motors would be a good place to start as they have a parts list on there website that employs all the original part numbers.

The back of the primary chain case can suffer from chain wear if chain adjustment and inspection is neglected, the back of this one has been severely worn through by the rear chain. Primary chain cases of this era of BSA C11 is made of pressed steel and are sealed by the outer cover of pressed steel.

The cork gasket that is sandwiched in between the cases should be the correct thickness and quality. Cork gasket material is available from StotfoldEngineering Company. The owner of the BSA C11 bought some footrest rubbers these did not fit as they were of modern BSA style with a square hole moulded into the centre. The footrest bars were of round section so I had to modify the rubbers by drilling with a round hole.

The combined petrol/oil tank with two filler caps is disastrously rotten and is going to be difficult to mend to give long service within the budget price. These tanks are unavailable even in India.

When pricing a restoration job one would expect a tank to be so rotten and difficult to restore to give a long service life. This is really the rotten tooth of the restoration.

The mud guards were really bad with many holes drilled in them, the front guard had broken in half and it needed brazing together. As can be seen in the picture all the holes were brazed. I prefer brazing to steel gas welding due to the lack of distortion. Brass has a lower melting point then steel so the surrounding metal needs less heat to create a bond, less heat, less distortion. Also brass does not rust. the number plate that slots into the front guard was supplied by the owner.

It was purchased from an aftermarket suppler and there was no way it was going to fit so I made a new one as you can see from the picture.