59 Triumph Bonneville motorcycle in Cambridge, MA

The 1959 Bonneville's frame is identical to that of the 1959 Tiger T110. Introduced on the 1954 T110, the rear swing arm was poorly supported in the frame and tended to flex, earning it the nickname "Whip Iron", due to its tendency to wobble and weave. This would be remedied in 1960 with the adoption of the new, and much-reviled 'duplex frame', which solved the swing arm issue, but brought with it a whole new set of problems.The footpegs attached direction to the engine mounting plates, between the engine and tranny, with the left one passing through the primary case (not good if you dropped it on that side, eh>). Rear shocks were fully-enclosed Girlings with 100 lb/ft spring tension and adjustable pre-set. The telescopic forks were straight off the 6T/T110 line. The bike sat on a 55-1/4" wheelbase with a 64-1/2 degree steering head angle. The frame was made by sweating or brazing steel tubes into cast lugs, which was standard practice for the day. Welded frames came much later.