FORK GETS THE KNIFE
After seeing my efforts with the Blackburne ‘Scarlet Runner’ project in recent months, Gus Mcintosh wondered if I could advise him on some problems with his Triumph Model H project. It, too, has seen service as a farm power plant and the girder forks have been sawn up. Made from tapered tubing, he’s not certain how best to carry out a repair and wonders whether tubing from some cycle forks could be salvaged or if he’d be better turning the taper on a piece of solid bar and using that.
Well, tapered tubing is difficult to find; originally swaged down in a rolling mill – a bit like rolling plasticene – it’s a specialist process that was probably quite affordable for Triumph, making thousands of Model Hs for the Great War, but that won’t help now. It’s worth contacting fork/frame repair specialists in case they’ve had any specially made up for jobs, but if not I wouldn’t recommend cycle tubing as an alternative. Weight’s critical on bicycles, so they’re made from as light material as possible; carrier cycles (grocer’s bikes) and early tandems are a possible exception – their parts were used for pioneer motorcycles, but generally cycle forks are adequate to carry the weight of a cycle and rider and no more. Double the weight and speed and they will be found lacking.
Making tubular parts from solid bar may raise an eyebrow, but I had a missing frame section made for my first flat-tank BSA by an engineer/blacksmith and he made it from solid. It was heavy but gave no problems, so I think in the absence of any other solution that may be the answer.
‘I DON’T RECOMMEND CYCLE TUBING AS AN ALTERNATIVE’