4

I have a Giant Revolt Advance 1 with SRAM Apex 1. The crank has 40 teeth. Which crankset should I buy if I want 32 teeth?

6
  • Is the crankset also Apex 1? If so, which exact model? You could just replace the chainring to a smaller one, but I can't tell you if there is a 32t chainring for the crankset without knowing the crankset. A picture might be easier.
    – abdnChap
    Jun 10 '20 at 9:32
  • @abdnChap I believe the Apex 1 crank should be something like a 110mm BCD. I don't believe it's physically possible for most such cranks to mount a 32t ring. A 33 is possible. However, I don't know if anyone makes 1x rings in that tooth count and that BCD for road.
    – Weiwen Ng
    Jun 10 '20 at 12:07
  • I know that you can get 34T narrow wide for 110mm BCD 5 bolt chainrings. I don't know if you're 100% fixed on 32T or not.
    – abdnChap
    Jun 10 '20 at 12:48
  • But also, just because they make them for 5 bolt, doesn't mean they will for Apex's 4 bolt
    – abdnChap
    Jun 10 '20 at 12:56
  • It does seem possible that there might be a 34T 110mm BCD 4-bolt chainring, like this one but I can't tell if that would work on Apex.
    – DavidW
    Jun 10 '20 at 13:43
1

SRAM Apex 1x crank supports 44, 43 and 40 tooth rings. To get to 32 teeth you'd need a mountain bike specific crank rather than a gravel groupset crank I think.

Whichever crank you select should have appropriate chainline. Presumably you have a through axle, 142mm spacing rear hub. There are plenty of MTB cranks that provide proper chainline for that.

Apex 1x comes in either GXP for a 68mm wide shell or 68mm BB30/PF30 bottom bracket versions. What you'll need is a MTB crank that fits whichever of those two you have.

I note the SRAM NX crank supports 30 to 36 tooth rings and comes in GXP and BB30/PF30 variants and supports 63 and 73mm shells. If you have the GXP bottom bracket you may have to swap out the bottom bracket for a MTB GXP one that will fit on a 68mm shell with 2x 2.5mm spacers to work with that crank. I'm not sure how compatibility with 68 vs 73mm BB30/PF30 works, perhaps spacers are used on the axle. You can obviously look further into compatibility on the SRAM site.

Another possibility is to use a bottom bracket from Wheels Manufacturing or a similar product to convert from the frame BB standard to a different crank BB standard.

5
  • I wonder if GXP cranks have different BB for mtb vs road. Like Shimano cranks do. Or if it would be a straight swap without needing new BBs
    – abdnChap
    Jun 10 '20 at 12:46
  • As in, the cups themselves are different or not. If the cups are the same, then you might only need the spaces to compensate for the 68 vs 73mm. In the same way, the actual cups themselves are different in shimano road vs mtb.
    – abdnChap
    Jun 10 '20 at 12:58
  • A major difference in Shimano Hollowtech II BBs between road and MTB versions is the length of the plastic tube in the middle that keeps dirt and water out of the bearings. Not sure if the threads are longer to allow spacers and maintain a minimum thread engagement. Jun 10 '20 at 13:23
  • Thanks for all The answers. I still find it difficult. I can’t inlude A photo. Jun 12 '20 at 6:57
  • @erikvanderkooij upload a photo to imgur or anywhere else accessible, put a link in your question and someone will edit it in for you. Jun 12 '20 at 10:50

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

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