I have posted some questions here regarding my search for a crank for my 76 90S. The bike is one I restored a couple of years ago, but was never happy with the level of vibration in the foot pegs. One of the things I like about the 90 motors is they are almost as smooth as a 75, but this one vibrated as much or more than the 100s I've ridden. So finally this winter I tore it back apart to find the crank was out of spec. So the search began for a replacement. I looked at five that for one reason or more felt weren't suitable. One of the most disappointing was from regular seller on IBMW, who turned out to be not only incompetent, but also dishonest. So finally I just started emailing people I had had contact with, who might have a lead on one. One such email went to our own Robert the Wirewerker. He said he had one but he would need to take it out and measure it. Measure it? This was something I had not heard from a seller before. So a couple of days later I hear back that it checks out to be very good. By this time I felt like UH HUH, we'll see. But a few days later Robert had the crank at my door and to my pleasant surprise I found the rod throws at the upper end of the spec, the mains fell into one of the color codes and they were all very round. Yesterday I took the bike out for a test run and found it to be a very smoooth running R90S. Up until then my 74 90S was the smoothest airhead I have ridden, now I'm not so sure. Oh, and many thanks to BMW Wrench for all the fitment clearance tips.