Why We Picked It:
Even Honda has made a few bikes it wishes it hadn't, but in the 1970s, with the relative success of the CB450T sport model, the suits in the boardroom at HQ wanted to capitalize. So they sent down an order to modify the 450 engine to a 500cc model, and, oh, to do it as "cost efficiently" as possible.
The truth about the CB450T was that it had a lot of sympathetic vibrations through the frame, but it was just, just below the annoying or uncomfortable level. Because the Honda engineers weren't allowed to make an all new 500cc engine, they took the 450cc unit, stroked it out, replaced the roller bearings with big ball bearings to "extend" the life of the engine, and didn't even modify the head unit, using it bone stock from the 450.
Because of that, they had to drop the compression from 9:1 to 8.5:1, mostly to allow it to use the cheapest gas possible, as the oil crisis was just kicking into high gear in 1975. Oh, and there was no real need to change out the 32mm carburetors, they should be just fine.
Add to that the rubber bushings, rubber handlebars, and rubber seat mounts were all of the cheapest, nastiest grade rubber possible. As a result, the CB500T vibrated like it had 17 cups of coffee and was trying to make its molecules separate at the speed of light. Even a short ride on the bike was so uncomfortable, shaking so violently, that if you had any fillings, they'd have been knocked loose.
Because the boardroom dictated the engineers make the bike, but then tied both hands behind their back and made the design it with their feet, the bike failed. Miserably. All the bike needed to succeed was something that already existed, and with more freedom, the engineers could have installed it: A counter balancer on the crank.