I just found this picture of a nice Velo Trials bike, that was built by Dave Lecoq. Dave used the machine for a good few years competing in events such as the Press Trial.
Dave is perhaps more famous for riding Clive Waye’s Drag-Waye dragster. Drag-Waye was a supercharged VW engine machine which completed the 1/4 mile in 9.68 seconds in 1970. In 1971 Dave and Drag-Waye took the world standing kilometre record with a 18.23s and the British 2 litre 1/4 mile record. Dave can still be seen racing Ray Petty’s 500cc racing car.
Going back to the Velo. It uses a very early Viper engine (which had heavier flywheels and an M17/7 cam). Dave chose a Velo engine due to the narrow engine – a theme that he kept to when building it. Dave manufactured a new sub-frame for the bike and also lengthened the Velo forks. The Velo wheels were replaced with much lighter items. Dave also made the oil tank, exhaust system and modified the petrol tank on the bike.