Going from 170 to 172.5 cranks - will I notice the diff...

CptKernow
CptKernow Posts: 467
edited December 2012 in Road general
I think my legs are reasonably short (31ins / 78.5cm - inside) so I've been using a 170 crankset. I'm quite happy with this but I've seen a new 172.5 chainset that I'd like.
Firstly would it make a noticeable difference? And secondly, if I have a 170 on my other bike could this cause any issues.

I'd assume the difference is pretty negligible, but then again...

Comments

  • ToeKnee
    ToeKnee Posts: 376
    Is everyone buying new cranks this Christmas - I thought tablets were de rigueur?

    Crank arm length -How important is it?
    Seneca wrote:
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    Specialized TriCross Sport+Ultegra+Rack&Bag+Guards+Exposure Lights - FCN 7
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  • rrsodl
    rrsodl Posts: 486
    I have 170, 172.5 and 175 and to tell you the truth, I wouldn't know which one is which unless I look. So my guess is that you wouldn't either. My leg length is 33 and a bit inches.

    You will need to lower the saddle a tiny bit and you should be OK. If the angle between ankle, knee and hip, when the pedal is up and crank is vertical to the floor, is 65 degree or more then you are fine.
  • drlodge
    drlodge Posts: 4,826
    CptKernow wrote:
    I think my legs are reasonably short (31ins / 78.5cm - inside) so I've been using a 170 crankset. I'm quite happy with this but I've seen a new 172.5 chainset that I'd like.
    Firstly would it make a noticeable difference? And secondly, if I have a 170 on my other bike could this cause any issues.

    I'd assume the difference is pretty negligible, but then again...

    I just switched from 170 to 172.5mm, and I'm 5' 9" tall, 33" ish inseam. Not much difference, may be a little more power up hill. May be. Feels nice though.
    WyndyMilla Massive Attack | Rourke 953 | Condor Italia 531 Pro | Boardman CX Pro | DT Swiss RR440 Tubeless Wheels
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  • danowat
    danowat Posts: 2,877
    No, you won't
  • Bordersroadie
    Bordersroadie Posts: 1,052
    My inseam is as yours. I went from 170 to 172.5 and noticed no difference. Just remember to lower your saddle by 1.25mm! :wink:
  • cougie
    cougie Posts: 22,512
    No.
  • CptKernow
    CptKernow Posts: 467
    Thanks for the replies.
    Read too much around this subject now. Seems most people say no difference, but at the end of the day I think I'm suited to a shorter crank so I may just have to cough up the extra £20 it'll cost me and have peace of mind

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