how many of you ride 170 vs 175 mm crank lengths? my new holzfellers are gonna be 170,should i have gotten 175? what is the benefit/difference between the two. obviously the 175 is longer and ur going to have more torque at your peak pedal but really how much difference does it make/feel??
crank lengths 175 vs 170
scottg07
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Guilty as charged, I'm a geek. 
kapusta, why yes, I was doing just that: guessing. That's what heuristics is about. Finding the least wild guess of all conceivable wild guesses. )
But take a look at what TNC just said. Namely, that there are sooo damn many things to consider (and what's worse - their effects differ in every case). I think that it just isn't worth doing that in a methodical way unless you're looking at some unusual crank lengths and unusual sized guy.
Also notice how I didn't outright suggest the 175 mm length but first proceeded to give an example of how such a difference works, as perceived by an average built person.
The question remains, however, just how did the 175 mm became so much of a standard? Even if it is formulated in terms of us being programmed by the industry into the use of 175 mm cranks, it's still a question worth asking.
I think that the answer to this is very much like the answer to many other bike design questions (like, why the spoked wheel, why the chain and cog transmission, why this wheel size for doing that, etc). Enter emergent algorithms... The bicycle as we know it is not a result of planned development. It is an ensemble of parts and practices that just... turn out... to play well together. No discernible authority is there to decide how an entire bike should look and work (even if some modern marketing strategies are trying to pull this off on us ). It's the generations of bikes that just keep proving themselves and selling themselves...
kapusta, why yes, I was doing just that: guessing. That's what heuristics is about. Finding the least wild guess of all conceivable wild guesses. )
But take a look at what TNC just said. Namely, that there are sooo damn many things to consider (and what's worse - their effects differ in every case). I think that it just isn't worth doing that in a methodical way unless you're looking at some unusual crank lengths and unusual sized guy.
Also notice how I didn't outright suggest the 175 mm length but first proceeded to give an example of how such a difference works, as perceived by an average built person.
The question remains, however, just how did the 175 mm became so much of a standard? Even if it is formulated in terms of us being programmed by the industry into the use of 175 mm cranks, it's still a question worth asking.
I think that the answer to this is very much like the answer to many other bike design questions (like, why the spoked wheel, why the chain and cog transmission, why this wheel size for doing that, etc). Enter emergent algorithms... The bicycle as we know it is not a result of planned development. It is an ensemble of parts and practices that just... turn out... to play well together. No discernible authority is there to decide how an entire bike should look and work (even if some modern marketing strategies are trying to pull this off on us
). It's the generations of bikes that just keep proving themselves and selling themselves...
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Have a read of this... http://www.sheldonbrown.com/cranks.html
And for those too lazy to read it all... best quote "I think people really obsess too much about crank length. After all, we all use the same staircases, whether we have long or short legs. Short legged people acclimate their knees to a greater angle of flex to climb stairways, and can also handle proportionally longer cranks than taller people normally use."
And for those too lazy to read it all... best quote "I think people really obsess too much about crank length. After all, we all use the same staircases, whether we have long or short legs. Short legged people acclimate their knees to a greater angle of flex to climb stairways, and can also handle proportionally longer cranks than taller people normally use."
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markw1970,
yes, I have read that some years ago.
But crank length is way more easier to tweak than staircases. ) Besides, whereas long legged people can just step over several small stairs at once, the short legged people are having hard time with tall stairs. That's why stair dimension standards have been emerging in building design throughout 20th century. Older buildings have much weirder and disparate stair sizes. Even older buildings have different height stairs within staircases...
More users, more use cases, more feedback, and voila! Before long the host of opportunities (most of them meaningless) converges into a few viable options (most of them meaningful). Evolutionary development in action...
yes, I have read that some years ago.
But crank length is way more easier to tweak than staircases. ) Besides, whereas long legged people can just step over several small stairs at once, the short legged people are having hard time with tall stairs. That's why stair dimension standards have been emerging in building design throughout 20th century. Older buildings have much weirder and disparate stair sizes. Even older buildings have different height stairs within staircases...
More users, more use cases, more feedback, and voila! Before long the host of opportunities (most of them meaningless) converges into a few viable options (most of them meaningful). Evolutionary development in action...
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I do notice the difference... with the 170 mm, the gears seem a little off (from being used to 175). But that's not anything to worry about. However I think that with say 165 mm it would have been harder to adapt to.
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Who has 172.5 mm cranks?Strafer said:
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so a 3% decrease in torque is insignificant but a 3% decrease in ground clearance is?Aust95 said:
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I used to have really old Deore 170s, then switched to new-ish STX-RCs at 175 and mistook the extra stiffness for better leverage until I recently bought Race Face Turbine LPs at 170 (and we know those stinkers are stiFF) and to be honest the difference in torque really is ~3% ...ie nothing, and the pedal clearance is a welcome + I can spin slightly faster cadences than before.
I feel the same way about 170's. I spin better, my knees are happier, and it's easier shifting weight from one side to the other. I've got 170's on my 2 26" full susser's and 175's on my SS 29er and SS 26er. The 175's are easier to mash up hills.heavyg said:
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A 3% loss in torque can be immediately made up for choosing another gear. If you are mashing up a hill at a race you will use a gear to get you up the hill that gets you up the hill fast. A crank arm won't be the deciding factor. And yes, I just brought back to life this dead thread!
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