I would like to buy a 4iii power meter integrated in a Shimano 105 crank arm.

On my bike I currently have SRAM Apex 1. Will this be possible?

Thank you!

  • 1
    We need more information about your bottom bracket shell. It depends entirely on it. SRAM cranks use the (awful) GXP standard, while Shimano has their own. Ie, it will be easy with a BSA threaded BB. With press fits you have to look at compatibility. Since Shimano offers their BB for many types of BB shells. Looking up the brand, model, and year of your bike will be a good start.
    – gschenk
    Commented Jan 20, 2020 at 23:51
  • Please also add the crank spindle standard of the 4iii crank.
    – gschenk
    Commented Jan 20, 2020 at 23:52

1 Answer 1


Your question is a little ambiguous but I think you are proposing to replace the Apex non-drive side crank arm with a Shimano 105 arm with a 4iii power meter built in. That will not work, the SRAM and Shimano cranks use a completely different attachment method.

4iii do not seem to offer power meters pre-installed in a new SRAM crank arm, but they do seem to offer to install a power meter unit in a arm you send to them, and list some SRAM options. You could contact them and see what SRAM cranks they can install a meter in, perhaps a Force 11 arm (which I think would be compatible) if they can't do an Apex.

Another option would be to look for whole power meter crank that is compatible with your bottom bracket.

  • If you use Look-type clipless pedals, a pedal based powermeter might be another solution. With the added advantage of an easy transfer between bikes.
    – Carel
    Commented Jan 21, 2020 at 12:16
  • Stages has a carbon GXP crankarm ($500), but that's the only pre-installed SRAM-compatible crankarm they have. I suspect options for SRAM are more limited because SRAM owns Quarq, which sells cranksets with spider-based power already. In addition, SRAM's Force and Red AXS cranksets have the option for an integrated spider-based PM. Both are very expensive. I have a feeling that @Carel is right, and the OP may want to think about a pedal-based solution. Alternatively, the OP could change their entire crankset.
    – Weiwen Ng
    Commented Jan 21, 2020 at 16:00
  • For the record, any bike with any Shimano hollowtech II crankset can take a 105 crankarm. Obviously it may look mismatched, but it will fit. That includes the current generation Claris mentioned at the link. Also, you can mix generations, e.g. put an R7k arm on a 5700 crankset, since they're both Hollowtech II. bicycles.stackexchange.com/questions/24798/…
    – Weiwen Ng
    Commented Jan 21, 2020 at 18:10

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