Changing SRAM Chainrings - compact and super compact options.....

Mike_Mac
Mike_Mac Posts: 46
edited September 2022 in Workshop
2 questions : 1 I think is obvious, the other maybe less.

I have bought a new bike with SRAM Force AXS etap with 48/35T (and a 10-33 cassette).

Q1: I can simply fit 46 & 33 SRAM force chainrings with the same BCD (in this case 107) onto the existing cranks and expect everything to work smoothly? (I'll also change the cassette to a 10 -36)

Q2: I've read here ("hack 3") that its possible to go super-compact 43/30 by using a spider Has anyone had any experience doing this method ? I may want to goto a min of 30 /36 when I'm touring - this "hack" seems too good to be true. EDIT - I know that Q2 is possible with buying wide crankset and wide derailleur (but that's expensive and possibly then restricting me to super compact)

Any help, really appreciated, especially on Q1 as that's likely going to be my first setup.

Mike

Comments

  • gethinceri
    gethinceri Posts: 1,575
    If the rear derailleur will manage it, why not stick a cassette with a 42 sprocket on?
  • It wont unfortunately , the Force derailleur has a max of 36T.
  • whyamihere
    whyamihere Posts: 7,708
    Q1 will definitely work. You will need to lower the front derailleur a bit and potentially need to resize the chain, though you may get away with that. Depending on how long it's all been running, a new chain sized correctly would probably be a good idea anyway. Q2 I don't know about, but 3T are generally pretty reliable with this information, so if they say it can be done it would probably be fine.
  • Mike_Mac
    Mike_Mac Posts: 46
    edited September 2022
    Thanks whyamihere!

    I understand why you say to get a new chain - I'll likely ride it a couple of times before changing over - around 200 km's should not affect the wear on the new cassette would it?

    It may of course just not physically work, then I've no option.....


  • whyamihere
    whyamihere Posts: 7,708
    200km shouldn't wear the chain/cassette sufficiently to worry about, assuming it's 200km on road and not 200km of sandy Belgian cyclocross. The main factor would be the chain length - You may need to add a link as 46-36 requires a slightly longer chain than 48-33, you might get away with it though.
  • Thank you!
  • For anyone looking to fit 43 / 30 chainrings ( 00.6218.015.005 & 00.6218.015.004) to their road / gravel bike without moving to a wider crank, I got confirmation from SRAM that its should certainly work.

    As explained in the 3T post - the 43/30t spider uses a smaller 94 BCD, so you would need to swap that out for our part number 11.6118.062.001.

    Amazing service at SRAM.


  • whyamihere
    whyamihere Posts: 7,708
    One point on the 43/30 - If you have a braze-on FD mount, you'll need to check you can get the FD low enough. The rings are designed to work with the wide FD, it's possible that also has a slightly different design to sit lower. If you have a band on FD this probably won't be an issue.
  • Thanks for the thought. It will be mounted on a Ti frame..

    Originally I had considered getting the whole wide setup crank set and FD. Costs and the wider Q factor put me off.

    Now that I know it's possible, I'm figuring out of I really need to go that low (!) and if I can live with 43 / 10 being my biggest ratio.

    It's all part of the fun!

    Mike