Can the crankset rings be swapped for smaller ones?

malahouse
malahouse Posts: 16
edited September 2018 in Workshop
Hello everyone.

I have looking at a Kona bike with 50/32 compact cranket and a Shimano 8 speed 11-32 cassette, with Claris shifters.

Is it possible to change the crankset to give me a lower gearing? For example, could I fit a 44/28 or 46/30 whilst remaining the same cassette? I am fine with 32 ring for everyday use, but I would fancy something lower for touring.

An ideal setup for me would be to change the crankset to a 46/30 and replace the 8 speed 11-32 with a 11-34. Would this product be feasible? https://www.spacycles.co.uk/m2b0s109p33 ... cral-Rings

Thank you.

Comments

  • cooldad
    cooldad Posts: 32,599
    Probably, but a bit of info helps.

    If your current crank has removable rings, you can probably just get a new chainring.

    Assuming you have a square taper BB already you may need to change it as axle length required depends on the crank.
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  • Mad_Malx
    Mad_Malx Posts: 5,174
    50-32 is a big jump already (more usually 50-34, i.e. 16 tooth difference), so you will likely need to change both rings if you go down this route. You may not get a smaller inner with a matching bolt circle diameter (BCD)

    Your spa cycles option crank swap is probably more sensible.

    Just reducing the front inner by 2 teeth isn't going to make a massive difference (probably less than one of your current rear shifts). A 44-28 might be a better combo, at present I suspect you never need the 50 front -11 rear.
  • Mad_Malx wrote:
    50-32 is a big jump already (more usually 50-34, i.e. 16 tooth difference), so you will likely need to change both rings if you go down this route. You may not get a smaller inner with a matching bolt circle diameter (BCD)

    Your spa cycles option crank swap is probably more sensible.

    Just reducing the front inner by 2 teeth isn't going to make a massive difference (probably less than one of your current rear shifts). A 44-28 might be a better combo, at present I suspect you never need the 50 front -11 rear.

    Thank you. Indeed it was a 50-34 (not 50-32). Basically I am trying to make the bike more touring friendly, without having to shell too much money. At present, the bike has a 50-34 with a 11-32t 7 speed. As you say I won`t be using the 50/11 gear. In practice, in every day cycling, a 50 chain ring will more a pain than anything else, in my case.

    It would more practical to swap the crankset with a 44-28 as you suggest. This would allow me to go fast if I need to, climb up without too much struggle, and shift less when cycling in the city.

    The current crainset is a FSA Temp Adventure 50-34T. This the bike http://www.wiggle.co.uk/kona-rove-2018-road-bike/

    Would you be able to suggest which brand/model of 44-28 crankset could I fit in there? As long as the whole replacement does not cost more than £100 it would still make sense for me.

    Thank you!
  • mercia_man
    mercia_man Posts: 1,431
    It appears that your current chainset - an FSA Tempo Adventure - uses a square taper cartridge bottom bracket. FSA does make a super compact version of this in 46/30 but it doesn't appear to be in stock anywhere that I can find. Its rings are 110 BCD outer and an unusual 80 BCD which don't appear to be made by the usual people like Stronglight and TA so replacing rings on your existing chainset will be a problem. If you can find this chainset in the super compact 46/30, I guess it would be a straight replacement onto your existing bottom bracket.

    So I reckon your best bet is a £69 Spa Cycles super compact chainset with a big choice of ring combinations (including 46/30 and 44/28) and crank length. It may fit direct onto your bottom bracket. If not, Spa Cycles' recommended 116mm bottom bracket is only £8 extra.
  • Why not go for an MTB crank? I believe that the pull is the same. You will probably require a matching FD too. You can move to HT2 at the same time.
  • Mad_Malx
    Mad_Malx Posts: 5,174
    I’d go with Mercia.
    Fallen’s suggestion prob ok too.