1969 BMW R75/5
With an experienced team and a lot of data.
The Japanese manufacturers presented a major challenge in the 1960s, but BMW responded in 1969 with the Slash Five series of bikes that were significantly different than their predecessors. They could even be had in colors other than black and white. The initial sign of change had been in the 1964 ISDT bikes, which gained the long-travel telescopic front forks that signaled the end of the Earles fork days. A new frame was developed along the lines of the Norton featherbed.
The new Slash Five bikes were introduced at the 1969 Cologne Motor Show and were presented in 500 cc, 600 cc and 750 cc forms. The R50, R60 and R75 shared an updated bottom end with different cylinders and pistons. Electric start was an option on the R50 but the R60 and R75 had electric and kick starts. Both the R50 and R60 had Bing slide carburetors while the R75 had new constant velocity carburetors.
The camshaft was relocated to under the crank, which improved oiling and made for a smoother overall appearance. The frame was now a welded up front unit with a large diameter oval lightweight spine tube, and a bolt-on rear swing-arm. Alloy wheels were 19 inches in front 18 inches at the rear. Instruments included a tachometer and warning lights, and a complete toolkit could be found under the seat.
Early complaints about high speed wobbles were resolved by lengthening the swing arm in 1972, while rear seal leaks were eventually defeated through the simple expedient of much harder running-in, which stopped the piston rings from glazing over. When that happened, if new bikes were babied, exhaust gasses passed the rings and pressurized the crankcase – especially since both pistons reached TDC together.
The Slash Fives were very well received, though the shiny “toaster” sides on the gas tanks were not to everyone’s taste. Few problems have been noted, though the wiring harness could use fuses. Engines can have top end rattle, which may just mean that the valves need adjusting. Rocker arms can be upgraded with needle bearings instead of the original plain bushings. Expect front springs to be soft, and watch out for center stand wear. When it’s down, both wheels should be off the ground. Sudden clutch take-up means the shaft is dry and if the twist grip feels rachety, it’s worn.
The Slash Fives proved very popular, with 7,865 R50/5, 22,721 R60 and a whopping 38,370 R75 models sold over a five year production run. Good original examples can be found, and brighter colors will cost more if they are correct.