I ordered a Nimbus 36H ISIS hub from UDC for a wheel that I’m building.
Finished up the wheel this morning and I was getting ready to install the cranks when I noticed that the spacers that came with the hub are two different thicknesses: one is 5 mm and the other is 6 mm.
I assume this is a mistake? I see no difference between left and right crank arms.
I’m putting on a pair of Venture cranks. Does anyone know what the correct spacer size should be? I was thinking that if it’s 5 mm, I could sand down the 6 mm one to match.
Maybe the perfect size is 5.5 mm and you have a 5 and a 6. Think how small a millimetre is, and how many variables there must be in manufacturing the hub, the cranks, the frame, etc. If it all fits together without any obvious forcing or rattling, I really wouldn’t assume it’s a problem unless you can see a problem.
You can ride without any with no real issue (maybe crank wear over time) if they aare torqued up tightly
1 mm is a reasonably large amount when it comes to the ISIS interface as the taper is only a few degrees.
I have several nimbus hubs and I think they come with 6mm (the UDC website says that is the size for venture cranks) so you may find the crank on the 5mm spacer sides binds up on the taper rather than being torques against the spacer
I would whack them on and see how they go and order some more spacers (or ask UDC to send a 6mm one to you which I am sure they will do)
I have a fair few spacers of different sizes in my bits box to tailor different crank and hub combos, at £1 a set it is worth getting a few sizes ans things stretch/wear over time etc
As long as you get resistance in the bolt before your crank bottoms out on the spacer there should not be an issue. You won’t notice one crank being 1mm further out.
If you need to make them smaller you can sand them down or cut some new ones. (a KH 27.2 seat post happens to be the right ID and OD)
As long as it’s not the adjustable OPC (oval inner diameter there).
P.S.: Was just searching for threads about spacers as i wasn’t sure if spacers are included when ordering a hub and how to find out which size i will need, etc.
Just to follow up on this, I contacted Unicycle.com after I realized that I had received two mismatched spacers with my hub and within 3 days I had a package in the mail from them: a bag of assorted spacers.
As always, first class customer service from UDC!