I am currently running a 10 speed groupset on a Giant Reign 2 2017 and I am looking to upgrade to a 12 speed DUB groupset. I'm wondering if this is possible with my current bottom bracket or what bottom bracket I would need to do it.

1 Answer 1


Giant uses Shimano's press fit BB standard - BB86 for road bikes, BB92 for MTBs. All you will need is a BB92 press fit BB for DUB spindles (some manufacturers may make BBs for 30mm spindles with a shim). For example, SRAM themselves make one such BB. Some manufacturers skip this combination, but there are a number of 3rd party manufacturers who offer it.

I have no direct experience, but I believe that some people are wary of using 29mm or 30mm spindle cranks in BB86 shells. Remember that Shimano has always stuck to a 24mm spindle, and they designed the shell without consideration of larger spindles. While you can buy a DUB or 30mm BB for that shell, there is less space for the bearings than if you used a 24mm spindle. Where space is constrained, a manufacturer can make the bearings smaller, but this decreases the amount of load the bearing can take and thus it may decrease bearing life. I'm not sure if there's a big penalty in real life.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.