I got myself a 2nd hand Shimano FC-M760 crankset for my Rohloff 1x drivetrain.
So far, I felt familiar with Hollowtech II and the 3×2.5mm Spacers required for using the shell in a 68mm BB frame.
However, I came across this strange spacer in the picture (about 6mm wide) that sits right on the spindle. Can be slid over the whole spindle but seems to belong to the right arm somehow.
Only Shimano Document I found listed the crank+BB parts, not including this one.
What is its purpose?
by esotericpragmatist
2 Comments
Without it, the inner chainring would hit the frame, and the inner chainring bolts might hit the bottom bracket. You’ll need to look up the chainline spec of your Rohloff, and use whatever spacers you need to make your chainring the same. So, with your configuration you might not need THAT spacer.
What bike frame do you have? How wide is the bottom bracket shell? What chainline are you trying to reach?
That crankset does not need that spacer to prevent interference between the inner chainring and the bottom bracket. I’m not sure why the other commentator believes such.
What I *suspect* we’re seeing is that the crankset came from a bike with a 68mm bottom bracket shell and, instead of using the bottom bracket spacers, the previous installer of this crankset used a spindle spacer to force most of the extra spindle length to one side, either to address chainline or frame clearance.
You are correct that it’s not a part that shipped with that crankset.
If that wide-spindle crankset is appropriate for your bike, then I’d ignore the fact that spacer came on the used part.