I have a Specialized Allez E5 from 2017 with Shimano Claris (8 speed) and I'm looking to replace my crankset.

I believe this is my current crank.

My specific and potentially stupid question - am I right in just looking for replacements that fit my BB or is there anything special I need to consider for the 8 speed? I'm probably going to get a like-for-like replacement in terms of teeth, ring size and so on.


2 Answers 2


is there anything special I need to consider for the 8 speed?

Yes, you specifically need an 8 speed crank.

8, 9, 10 etc speed group sets use progressively narrower chains, and the cranks have narrower chainring spacing to suit.

Many people seem to think you can get away with one speed difference and there are special shims available that adjust chainring spacing but it’s easier to just get a explicitly compatible crank.

Be aware that FSA MegaExo road (68mm shell) is dimensionally the same as Shimano Hollowtech II road, so you can fit a Shimano crank. Personally if I were upgrading to a Shimano crank I’d upgrade the bottom bracket to a Shimano unit also.

  • Thank you very much. I have ordered a Shimano Claris FC-R2000 based upon your response. It seems to have been discussed quite a lot on the Internet before and I am stupid enough to not find that information without assistance. So once again, thank you very much! Commented Aug 26, 2020 at 13:54
  • I thought (not sure why...) that one would be safe in going up slightly-- using a 9-speed crank on an 8-speed bike. Any thoughts on that practice, @Argenti Apparatus? Edit: Here's why I thought that: sheldonbrown.com/speeds.html
    – Andrew
    Commented Aug 26, 2020 at 17:27

You can get any 8-speed crankset that fits your BB, that means not just the spindle diameter, but also the axle length - that means a road one. If it is a road one, you should get the right chainline without much worrying.

You can also get many other 8-speed cranksets, provided you also buy the right BB, they are much cheaper than the cranksets. That mostly depends on the manufacturer, because the newer BB standards are proprietary. Shimano will use Hollowtech II or older Octalink, FSA will use MegaExo and so on. Only cheaper cranks will typically use the universal square taper.

  • Thank you very much Vladimir. Your information, combined with the other response, helped me purchase what I needed. Thanks! Commented Aug 26, 2020 at 13:55

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