Achieving Correct Beltline for Gates Carbon Drive

Question

I’m building up a Soma Wolverine with a Gates Carbon Drive and Alfine 11 internal gear hub. The Gates literature indicates that the beltline should be 43.7 mm +/- 1mm.

I am trying to use an old crankset I have on-hand, a Sugino RD2, which has a 45mm chain line when using a 103mm bottom bracket. Obviously this is slightly out of spec with the Gates belt line requirements

My question is, can I use an adjustable Phil Wood bottom bracket to make up the 0.3-1.3 mm difference in beltline? Would it be better to have the bottom bracket built with an offset spindle, which it sounds like Phil Wood can do? Or best to just buy a crankset from Gates?

michaelmichael · Accepted Answer

I did end up completing this project. I talked to several people, just calling up bike shops that sold or specialized in belt drive bikes and asking for opinions.
I spoke with someone—I think it was a fellow at Ben's Cycle/Milwaukee Bicycle Co.—who had lots of experience fitting belt drives to frames. He had even worked with Gates on building several belt drive-specific bikes. His take was that I was worrying about nothing. A 45 mm belt line was well within what he would expect to work without issue, even if it was specced for 43.7 mm. I even tried to let him talk me into buying a fancy Phil Woods bottom bracket or a Gates crank and BB set. He said it would not be worth it in this instance. 45 mm was close enough to work.
At that point I just went ahead and installed my 103 mm bottom bracket and the Sugino RD2 cranks. I finished the bike and have been riding it pretty much daily since. I don't think I'll go back to chains if I can help it. The Alfine hub shifts super smoothly. The whole setup is quiet and reliable. It's great not worrying about keeping a chain clean and oiled. I highly recommend it.

Achieving Correct Beltline for Gates Carbon Drive

One Answer

Add your own answers!

Ask a Question