cut it in the deserts of Nevada . Feedback from the ISDT team riders suggested the bike was also too cumbersome . To address these shortcomings , Triumph took the lightweight rigid frame from its 3T trials bike , shortened the frame by cutting the front down tube and incorporating the generator inside the front engine mounts and added the 500cc engine , complete with its lightweight alloy top end parts . Launched at the Earls Court Motorcycle show in 1948 , the TR5 Trophy proved to be a winning combination , described in the Triumph literature as a bike “ specially tuned for reliable slow pulling ” while having “ ample power for the highest speeds .” The engine was an overhead valve 498cc parallel twin with 63mm x 80mm bore and stroke . The early versions retained the barrels and heads from the wartime generators and these are identifiable by coarser fins , straight exhaust ports and cast-in lugs where cooling shrouds would have been bolted . In standard trim it ran 6:1 compression , producing 25bhp at 6000rpm – good for over 80mph . In the optional ISDT trim with 7.5:1 pistons , the increase in power enabled the TR5 to reach a shade under 100mph . The carburettor was an Amal 276-type and electrical power came from a BTH or Lucas K2F competition magneto .
48 KIWI RIDER