The Way It Was
The Way It Was
While Managing Editor Matthew Miles thinks about the question of whether or not a privately entered AMA Pro Racing American Superbike can be competitive, I think of my own experience in 1974, when Yamaha first released the four-cylinder TZ750A. Our dealer, John Jacobson of Boston Cycles, ordered one in a completely routine way—for $3500. Its crankshafts and many of its other parts were based upon the same production module as the TZ350 and TA250 Twins, which,
in turn, were based on the R5 production bike. Therefore, it was no problem for me to change the main bearings before first start-up, per a service bulletin and supplied bearing kit. I also did not like the look of the production flat-sided exhaust pipes (I had seen such pipes fracture in the past), so I made a pair of round 2-into-1 pipes to replace them. Otherwise, I just went through the machine to be sure it was correctly assembled.
Our rider, Jim Evans, had no prior 750 experience, having ridden the conservatively built Twins of Mel Dinesen. We had a chain failure at Daytona and broke a second gear at Loudon. Then at Talladega, Jim was very fast and his bike went straight. Others did not— Dave Smith, after a 160-mph high-speed weave, sat white-faced and clearly shaking in his lawn chair. I saw Don Castro’s feet flung off the pegs of his factory bike as it hit violent weave past start/finish. The problem? A little groove for a wire circlip in the fork dampers needed to be 0.005-inch deeper. When the fixing bolt at the bottom of each fork leg was tightened at the factory, the circlip popped out, making the dampers inoperative.
Jim was third on Sunday, behind two factory bikes. He was third again at Ontario Motor Speedway, after briefly leading one of the two legs. Ahead of him? Two factory Yamahas. At the teardown, we saw the fourth-place bike, leaned against the wall in a hallway. It was Barry Sheene’s factory Suzuki. Jim Evans had distinguished himself. Not bad for a 750 beginner, on a bike bought for cash, in a world free of “A-kits,” special chips (“Chip? What’s a chip?”) and GPS-linked control electronics.
Kevin Cameron
