Pro's and cons of shorter crank arms?

2

Comments

  • amrushton wrote:
    Your feet are turning smaller circles using smaller cranks (pi x d) so in effect a smaller lever, higher cadence but your seat height goes up. Both Wiggins and Cavendish use 170mm cranks and those 2 are a few inches different in height.

    Wiggins has taken to using shorter cranks to emulate his track setup - though it does help to show that it doesn't matter that much in power output terms.
  • It's less about power output and more about comfort in the long term. And indeed someone who is fit and supple might be able to use any length effectively but if you're not fit and supple or have long term injuries it may be more of a concern.
  • I've just noticed after a layoff from road cycling, due to hip pain, that my cranks are 180mm on my road bike.
    My mtb does not exacerbate the pain (175mm cranks, wider q-factor).
    I'm 5'8" and just ordered 165mm compacts for the roadie after doing some research on the subject.
  • StillGoing
    StillGoing Posts: 5,211
    ravey1981 wrote:
    I call BS on anyone who says they can tell the difference between a 170 and a 172.5 etc. Its 2.5mm, If I came and raised your seat by 2.5mm without you knowing you would never, ever know. If they only made two lengths with about 15mm difference, one for shorties and one for the longer legged person then I could understand it. I've got different lengths on all my bikes pretty much because either they were cheap at the time or its what the bike came with.

    You can't judge every one else by your own inabilities. I can tell and that is all that matters to me. You can't so bad luck.
    I ride a bike. Doesn't make me green or a tree hugger. I drive a car too.
  • try this video on crank length, much better than the one on GCN https://www.youtube.com/watch?v=Yl90KFqDW-Y
  • 5mm across axles. Does anyone know the best time of day for a bike fitting session? I was told the spine from morning to night varies in length and it can throw off the stem measurement. I generally ride evenings throughout the week and then a couple of mornings over the weekend.. Given I ride more during the week I kind of thought a bike fit around 4pm would give best results, but I do prefer the weekend rides and think it might be best to have the exact riding position for those rides, so a morning session.. or I guess a fitting around midday would average better? such a dilemma.
  • DKay
    DKay Posts: 1,652
    ravey1981 wrote:
    I call BS on anyone who says they can tell the difference between a 170 and a 172.5 etc. Its 2.5mm, If I came and raised your seat by 2.5mm without you knowing you would never, ever know.

    I can tell you with 100% confidence that I'd be able to tell a 2.5mm difference in saddle height, up or down from my normal setting.
  • Anonymous
    Anonymous Posts: 79,667
    DKay wrote:
    ravey1981 wrote:
    I call BS on anyone who says they can tell the difference between a 170 and a 172.5 etc. Its 2.5mm, If I came and raised your seat by 2.5mm without you knowing you would never, ever know.

    I can tell you with 100% confidence that I'd be able to tell a 2.5mm difference in saddle height, up or down from my normal setting.

    So could you notice the difference in the thickness of the padding in your bib shorts? After time I am pretty sure they would change in thickness of a few mm. Or do you adjust your saddle to compensate?
  • DKay
    DKay Posts: 1,652
    So could you notice the difference in the thickness of the padding in your bib shorts? After time I am pretty sure they would change in thickness of a few mm.

    Do you know this for sure? No you don't. Even if it were true, it would occur over such a long, graduated period that any difference, would indeed be very hard to notice.

    However, if I were to adjust my saddle height 2.5mm either way from one ride to the next, the difference would be very obvious to me. You're insensitive to small saddle height changes, I'm not. Why is that so hard for you to accept?
  • DKay
    DKay Posts: 1,652
    So could you notice the difference in the thickness of the padding in your bib shorts? After time I am pretty sure they would change in thickness of a few mm.

    Do you know this for sure? No you don't. Even if it were true, it would occur over such a long, graduated period that any difference, would indeed be very hard to notice.

    However, if I were to adjust my saddle height 2.5mm either way from one ride to the next, the difference would be very obvious to me. You're insensitive to small saddle height changes, I'm not. Some people have much more sensitive hearing, eyesight, sense of taste, etc, etc. This is a fact, which for some strange reason you seem to find hard to accept.
  • Anonymous
    Anonymous Posts: 79,667
    DKay wrote:
    So could you notice the difference in the thickness of the padding in your bib shorts? After time I am pretty sure they would change in thickness of a few mm.
    Some people have much more sensitive hearing, eyesight, sense of taste, etc, etc.

    And you have a super sensitive @ss!!

    Who knew?
  • DKay
    DKay Posts: 1,652
    edited September 2016
    DKay wrote:
    So could you notice the difference in the thickness of the padding in your bib shorts? After time I am pretty sure they would change in thickness of a few mm.
    Some people have much more sensitive hearing, eyesight, sense of taste, etc, etc.

    And you have a super sensitive @ss!!

    Who knew?

    You're coming across as an idiot. You notice changes in saddle height due to the changes in the amount of extension of your legs and the change in the amount of knee lift. :roll:
  • Anonymous
    Anonymous Posts: 79,667
    DKay wrote:
    DKay wrote:
    So could you notice the difference in the thickness of the padding in your bib shorts? After time I am pretty sure they would change in thickness of a few mm.
    Some people have much more sensitive hearing, eyesight, sense of taste, etc, etc.

    And you have a super sensitive @ss!!

    Who knew?

    You notice changes in saddle height with either the greater extension of your legs or the higher knee lift. :roll:

    2.5mm is minute. Most people shift about forward or backward more than that on an average ride. Or does your super sensitive ass know exactly what part of the saddle to be on at all times?
  • DKay
    DKay Posts: 1,652
    2.5mm is minute. Most people shift about forward or backward more than that on an average ride. Or does your super sensitive ass know exactly what part of the saddle to be on at all times?

    What a silly comment. Any change in saddle height will affect your pedalling stroke no matter where you sit on the saddle. If I were to change my saddle height by 2.5mm, then riding on the nose will feel different to me than if I were riding on the nose at my normal height. Climbing while seated at the rear of the saddle will feel different than if I were climbing while seated to the rear at my normal height. Do you understand this?

    At the end of the day, I feel a difference through my legs (not my ass, as you seem to ignorantly keep saying) you don't. That's fine. If you are happy to believe that you are correct and that everyone who notices small saddle height differences is a fraud, then that's also fine. I've wasted enough of my time here already.
  • Anonymous
    Anonymous Posts: 79,667
    DKay wrote:
    2.5mm is minute. Most people shift about forward or backward more than that on an average ride. Or does your super sensitive ass know exactly what part of the saddle to be on at all times?

    What a silly comment. Any change in saddle height will affect your pedalling stroke no matter where you sit on the saddle. If I were to change my saddle height by 2.5mm, then riding on the nose will feel different to me than if I were riding on the nose at my normal height. Climbing while seated at the rear of the saddle will feel different than if I were climbing while seated to the rear at my normal height. Do you understand this?

    At the end of the day, I feel a difference through my legs (not my ass, as you seem to ignorantly keep saying) you don't. That's fine. If you are happy to believe that you are correct and that everyone who notices small saddle height differences is a fraud, then that's also fine. I've wasted enough of my time here already.

    You obviously don't know when you are being wound up cos you keep biting.
  • DKay
    DKay Posts: 1,652
    You obviously don't know when you are being wound up cos you keep biting.

    Mental note made for future reference that you're a knob.
  • Anonymous
    Anonymous Posts: 79,667
    DKay wrote:
    You obviously don't know when you are being wound up cos you keep biting.

    Mental note made for future reference that you're a knob.


    Wow I was right. You are a super sensitive ass. Stop dripping like a f*cked tap.
  • StillGoing
    StillGoing Posts: 5,211
    DKay wrote:
    DKay wrote:
    So could you notice the difference in the thickness of the padding in your bib shorts? After time I am pretty sure they would change in thickness of a few mm.
    Some people have much more sensitive hearing, eyesight, sense of taste, etc, etc.

    And you have a super sensitive @ss!!

    Who knew?

    You notice changes in saddle height with either the greater extension of your legs or the higher knee lift. :roll:

    2.5mm is minute. Most people shift about forward or backward more than that on an average ride. Or does your super sensitive ass know exactly what part of the saddle to be on at all times?

    It isn't 2.5mm. Whilst 2.5mm might be the difference in the length of the crank arm, the overall difference is 5mm. The shorter crank arm at the bottom of the stroke means the seat is raised by 2.5mm, but, the clearance at the top of the stroke is now 5mm giving that amount of additional clearance and allowing the rider to get onto the power stroke easier.

    You reckon you're on a wind up, but I doubt it by reading all of your contributions to this thread. You're just being dismissive of something that you refuse to acknowledge others benefit from and are now trying to back track by claiming you're simply being a troll. :roll:
    I ride a bike. Doesn't make me green or a tree hugger. I drive a car too.
  • pblakeney
    pblakeney Posts: 27,083
    The downside (pun intended) is that you also have 2.5mm less leverage.
    Therefore getting on the power earlier but less power output. Worthwhile?
    The above may be fact, or fiction, I may be serious, I may be jesting.
    I am not sure. You have no chance.
    Veronese68 wrote:
    PB is the most sensible person on here.
  • StillGoing
    StillGoing Posts: 5,211
    PBlakeney wrote:
    The downside (pun intended) is that you also have 2.5mm less leverage.
    Therefore getting on the power earlier but less power output. Worthwhile?

    The longer lever makes it easier to move a given mass, but does it necessarily have an effect on your watts per kilo?

    figure3.png
    I ride a bike. Doesn't make me green or a tree hugger. I drive a car too.
  • Anonymous
    Anonymous Posts: 79,667
    philthy3 wrote:
    DKay wrote:
    DKay wrote:
    So could you notice the difference in the thickness of the padding in your bib shorts? After time I am pretty sure they would change in thickness of a few mm.
    Some people have much more sensitive hearing, eyesight, sense of taste, etc, etc.

    And you have a super sensitive @ss!!

    Who knew?

    You notice changes in saddle height with either the greater extension of your legs or the higher knee lift. :roll:

    2.5mm is minute. Most people shift about forward or backward more than that on an average ride. Or does your super sensitive ass know exactly what part of the saddle to be on at all times?

    It isn't 2.5mm. Whilst 2.5mm might be the difference in the length of the crank arm, the overall difference is 5mm. The shorter crank arm at the bottom of the stroke means the seat is raised by 2.5mm, but, the clearance at the top of the stroke is now 5mm giving that amount of additional clearance and allowing the rider to get onto the power stroke easier.

    You reckon you're on a wind up, but I doubt it by reading all of your contributions to this thread. You're just being dismissive of something that you refuse to acknowledge others benefit from and are now trying to back track by claiming you're simply being a troll. :roll:

    I originally said I noticed zero performance change from 165mm to 170mm. That is 5mm. I also said becsuse of that the difference to 172.5 from 170 woild so so insignificant you would not notice. I am not just a guy who rides every sunday to the shops. I have raced plenty over the last decade or so. I am not new to this. Plenty dismiss is. I was taking the piss out of the fact he was saying he can tell the difference in 2.5mm . That i doubt. And it would only be 2.5mm not 5mm as its the measurement from pedal to saddle.

    So. Philthy. If you are going to jump into a thread to stirr up hatred and call people trolls you better et your facts straight.
  • DKay
    DKay Posts: 1,652
    philthy3 wrote:
    You reckon you're on a wind up, but I doubt it by reading all of your contributions to this thread. You're just being dismissive of something that you refuse to acknowledge others benefit from and are now trying to back track by claiming you're simply being a troll. :roll:

    These were my thoughts too. As in my possible naiveity, I refuse(d) to believe that somebody could be so ignorant to think that their own experience must automatically be the same as everyone elses and therefore resort to taking the mick out of anyone, who's experience differs from theirs.

    In this instance, it would seem that I was completely wrong.
  • DKay
    DKay Posts: 1,652
    I am not just a guy who rides every sunday to the shops. I have raced plenty over the last decade or so. I am not new to this.

    What's your point? If you're insensitive to small saddle height changes, it doesn't matter if you've only been riding for a few weeks or multiple decades, you're still not going to feel it. Only in this particular case, you somehow seem to think that everyone else is physiologically the same as you. :roll: Having experience at something, doesn't preclude you from being a troll.
  • pinno
    pinno Posts: 52,161
    Yay! Popcorn time.

    How about this:

    https://www.youtube.com/watch?v=eMAxH_Ud8YE
    seanoconn - gruagach craic!
  • Anonymous
    Anonymous Posts: 79,667
    Pinno wrote:
    Yay! Popcorn time.

    How about this:

    https://www.youtube.com/watch?v=eMAxH_Ud8YE

    At least you have a SOH Pinno. Unlike some who take everything so personal and literal. Its an open forum. No place for the faint hearted.
  • DKay
    DKay Posts: 1,652
    Pinno wrote:
    Yay! Popcorn time.

    How about this:

    https://www.youtube.com/watch?v=eMAxH_Ud8YE

    At least you have a SOH Pinno. Unlike some who take everything so personal and literal. Its an open forum. No place for the faint hearted.

    For a sense of humour to appear, something has to be funny in the first place or clearly meant in jest. You failed on both counts.
  • Anonymous
    Anonymous Posts: 79,667
    DKay wrote:
    Pinno wrote:
    Yay! Popcorn time.

    How about this:

    https://www.youtube.com/watch?v=eMAxH_Ud8YE

    At least you have a SOH Pinno. Unlike some who take everything so personal and literal. Its an open forum. No place for the faint hearted.

    For a sense of humour to appear, somiething has to be funny in the first place or clearly meant in jest. You failed on both counts.

    Why do you keep biting? Are you that sad thatyou can't let anything go. You call me all you want. IDGAF. But you leave yourself open to anyone else to wind you up in future.
  • DKay
    DKay Posts: 1,652
    You are clearly mistaking 'biting' as 'pointing out your complete ignorance'.

    You're only saying I'm 'biting' as that's all you've got left. That's what's really sad my friend.

    Finally, for somebody who DGAF, you're contradicting yourself spectacularly with your multiple replies. :lol:
  • pinno
    pinno Posts: 52,161
    duty_calls.png
    seanoconn - gruagach craic!
  • diamonddog
    diamonddog Posts: 3,426
    Pinno wrote:
    duty_calls.png
    :lol::lol::lol: