I wanted a “medium” touring bike, so I got an A Homer Hilsen frame. I was also impressed with how the 24mm, eternal bearing, Hollowtech II drive system felt. It was, to my feet, noticeably stiffer than the square taper BBs I had been using for years.
So, loath to screw up a Rivendell frame, I bought an ’82 Team Fuji from Craigslist, and used the rebuild of that to determine how to pull a square taper BB and put on the Hollowtech BBR60. I also put on a few other goodies (Sora 3030 system,105 brakes, Velocity Road rear hub, re-laced the wheels) to learn how it all worked. I learned that those spacers we’ve been referring to are fragile and don’t want to be between two moving parts. Also that you put the drive side external cup on, then run the crank through, then screw on the non-drive side cup instead of trying to push the crank through a fully assembled BB (my LBS taught me that). Also that putting on the crank, then measuring the chainline, then pulling off the crank to change the drive side spacers was an iterative process. Then I built up the Homer with the MT800 BB and the Shimano FC-M590 triple crank. It only took one iteration of spacers to get the chainline. The MT800 worked perfectly on the 68mm BB shell. I also - wanting to see if this stuff was interchangeable - pulled it all off at one point and tried a Token TK878EX BB. The Token was cheaper then, and came in AHH Blue. It also worked perfectly. The Homer was not my longed-for perfect tourer, so I passed it on for a Soma Saga. But I kept the drive and BB. The Saga also has a 68mm BB shell and 135mm rear spacing. Only one iteration to get the spacers/chainline right, and they are a different config from the Homer, but it works great. Other lessons learned - the 24mm bottom bracket is more fragile than a sealed square-taper BB (also more fragile than the good old 1/4 inch ball bearings in an un-sealed square-taper setup). I ruined one 24mm BB before I asked my LBS and got a lesson in installation. I also got told that the 24mm BB has to be replaced more often just from use. I haven’t killed one yet, but if your crank starts making a hissing sound, check the BB first. Going back to Keith’s original post, a little asymmetry is the price paid for a correct chainline when your crank shaft is fixed length. Spacers and assembly iterations are the price paid for a 24mm BB that is supposed to fit both 73mm and 68mm shells - it must be built for the bigger size. Max, the MTN should work fine, for a few grams extra weight, and might last longer. And, finally, if you hit a snag ask your LBS. They've had to deal with this stuff for years. -- You received this message because you are subscribed to the Google Groups "RBW Owners Bunch" group. To unsubscribe from this group and stop receiving emails from it, send an email to rbw-owners-bunch+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/rbw-owners-bunch/2dd0308e-278b-4cbf-bdc4-955ad2ca80e2n%40googlegroups.com.
