The importance of crank length to the cyclist.

[FrankDay]

How about you try again without the point scoring? Are you telling us that - in the context of your statement that all riders are pretty much alike - that the heights, inseams, relative femur lengths, hip flexion, relative torso lengths, tibial lengths, muscle compositions, etc, etc of Bradley Wiggans and Thomas Voeckler are "pretty much alike"?

Well, those numbers you list are not pretty much alike but those numbers represent relatively tiny variations compared to the "pretty much alike" that I am talking about, the general anatomy of the human being.

If that were true then there would be one bike frame size with one set of frame angles, a fixed stem/bar combo with no adjustment, non adjustable saddles, etc

Why would we expect that. In fact, now that you brought it up, why is it that there are hundreds of different cyclist heights who also vary in all those other measurements with probably close to a 100% variability in size, maybe 20 different frame sizes available with an approximate 50% variability in size, but readily available and used crank lengths for the vast majority of all those represented above lie between 165 and 180 mm (an approximate 10% range (with the vast majority of those being between 170 and 175, an approximate 3% variation). It is simply non-sensical to think that a 4'10" woman and a 6'6" man can all be optimally fitted to this small range of crank sizes. Yet, that is what the crank manufacturers demand and the cyclists, including the professional bike fitters, seemingly slavishly believe.

We don't - and that is the basis for my comment earlier that even if research shows something has benefit for the 'average' cyclist, you still need to check it out for yourself if it changes your position. its not the same as buying a set of Zipps (and even with deep section rims, what works for the average rider could still put a lightweight climber into a tree due to wind effects)

Aren't I arguing the same thing. In fact, I think it so important I have made it easy for the athlete who also wants to use my product to also experiment with this also. And, I encourage those who don't want to use my product to experiment with this anyhow.

 

[Martin318is]

Well, those numbers you list are not pretty much alike but those numbers represent relatively tiny variations compared to the "pretty much alike" that I am talking about, the general anatomy of the human being.

no you weren't Frank - here is your comment, to remind you of what you meant:

I have a problem with the "some would improve and others would not" since we are all built pretty much the same and all fit pretty much the same on a bicycle

The reality is - as you said - that you and I agree on part of this but as I just pointed out, the differences between two riders can be relatively massive in terms of leverage so it is entirely logical that there would be variation in response to changing a variable.

Why would we expect that. In fact, now that you brought it up, why is it that there are hundreds of different cyclist heights who also vary in all those other measurements with probably close to a 100% variability in size, maybe 20 different frame sizes available with an approximate 50% variability in size, but readily available and used crank lengths for the vast majority of all those represented above lie between 165 and 180 mm (an approximate 10% range (with the vast majority of those being between 170 and 175, an approximate 3% variation). It is simply non-sensical to think that a 4'10" woman and a 6'6" man can all be optimally fitted to this small range of crank sizes. Yet, that is what the crank manufacturers demand and the cyclists, including the professional bike fitters, seemingly slavishly believe.

Wrong. The crank makers don't deman anything - they react. They do this as a response to the economies of scale. It is more cost effective for them to make 172.5mm cranks because they go on the majority of frames sold. They don't make 110mm cranks in bulk for the same reason that female cyclists have trouble finding other components - the cost in making them outweighs the profit made in selling one or two now and then. For the same reason it is easy to get a size 44 or 45 cycling shoe but relatively difficult to get a 38 or lower.

Other than this, I agree with the point. It would be great if you could get any part in any size that you wanted without being stuck with this problem. If only we could ALL afford to get custom frame geometry for instance. It would be awesome.

Aren't I arguing the same thing. In fact, I think it so important I have made it easy for the athlete who also wants to use my product to also experiment with this also. And, I encourage those who don't want to use my product to experiment with this anyhow.

The bit in bold is a good point Frank. I think you have created a list of 'friends' and a list of 'enemies' on this (and other topics) and when you see a post from one of those people you seem to respond to what you think they said rather than the text that is actually there.

For instance, you wrote something and I posted to highlight that what you wrote could have been written better. Instead of sitting back and taking a moment to think about whether I was right and modifying your statement - you responded in a very patronising fashion that very much appeared to be trying to smack me down through portraying the 'appearance' that you are smarter than everyone (accusations regarding comprehension, etc), just because I 'disagreed' with you. As a way of dealing with potential customers, it leaves a little to be desired...

 

[FrankDay]

no you weren't Frank - here is your comment, to remind you of what you meant:


The reality is - as you said - that you and I agree on part of this but as I just pointed out, the differences between two riders can be relatively massive in terms of leverage so it is entirely logical that there would be variation in response to changing a variable.

Oh phooeey. Are you really trying to tell me that if I showed you a silhouette side view of a rider and took away the bicycle, wheels, sex and other clues (we would have to put them all on the same relative crank length to their height), just showing you how the rider fit on the bicycle, that you could tell me whether the rider was big, small, had a long or short femur or anything else from this information? I simply don't believe it.

Wrong. The crank makers don't deman anything - they react. They do this as a response to the economies of scale. It is more cost effective for them to make 172.5mm cranks because they go on the majority of frames sold. They don't make 110mm cranks in bulk for the same reason that female cyclists have trouble finding other components - the cost in making them outweighs the profit made in selling one or two now and then. For the same reason it is easy to get a size 44 or 45 cycling shoe but relatively difficult to get a 38 or lower.

Well, then you are letting these folks determine what is best for you by letting them use as their criteria as to what is best for you, what is best for their bottom line. If you are serious about racing why would you let this happen? And this coming from someone who has no trouble, apparently, spending thousands on unproven items such as a PM, but won't spend $20-50 on some cheap cranks on the internet to do this experimentation.

Other than this, I agree with the point. It would be great if you could get any part in any size that you wanted without being stuck with this problem. If only we could ALL afford to get custom frame geometry for instance. It would be awesome.

My athletes report they can find these things in all sorts of sizes for less than $50. I can hardly think of a cheaper device to get if one would want to experiment with this a bit. My cranks are only expensive because of the PowerCranks part of the device.

The bit in bold is a good point Frank. I think you have created a list of 'friends' and a list of 'enemies' on this (and other topics) and when you see a post from one of those people you seem to respond to what you think they said rather than the text that is actually there.

For instance, you wrote something and I posted to highlight that what you wrote could have been written better. Instead of sitting back and taking a moment to think about whether I was right and modifying your statement - you responded in a very patronising fashion that very much appeared to be trying to smack me down through portraying the 'appearance' that you are smarter than everyone (accusations regarding comprehension, etc), just because I 'disagreed' with you. As a way of dealing with potential customers, it leaves a little to be desired...

I am sorry that you felt my pointing out that I have been encouraging the reader to experiment with this since the very first post in a thread that now has over 800 replies was patronizing towards you.

 

[FrankDay]

For the same reason it is easy to get a size 44 or 45 cycling shoe but relatively difficult to get a 38 or lower.

How many riders who have a size 38 foot do you think go ahead and buy the size 44 shoe because that is what the bike store has in stock and it is just too much trouble to find a shoe that fits? Thick socks and some paper in the toes and they can learn to adapt just fine, I am sure.

My point is, if you are serious about racing why don't you try to make the bike fit what is best for you rather than trying to make you adapt to your bike? We do it with everything else. Why is crank length considered the ugly step sister and pretty much ignored?

 

[Martin318is]

How many riders who have a size 38 foot do you think go ahead and buy the size 44 shoe because that is what the bike store has in stock and it is just too much trouble to find a shoe that fits? Thick socks and some paper in the toes and they can learn to adapt just fine, I am sure.

My point is, if you are serious about racing why don't you try to make the bike fit what is best for you rather than trying to make you adapt to your bike? We do it with everything else. Why is crank length considered the ugly step sister and pretty much ignored?

Dealing with your posts in reverse:

Once again, you go the attack on me where all I did was clarify the reason something was happening and gave no indication that I thought it was a good thing - infact I indicated I agree with you.

You're paranoid Frank.

I am sorry that you felt my pointing out that I have been encouraging the reader to experiment with this since the very first post in a thread that now has over 800 replies was patronizing towards you.

This is just pathetic Frank. I made clear reference to several posts of yours that mocked the comprehension skills of contributors to this thread. Don't try to defend your poor behaviour by twisting my comment and trying to make it apply to the entire thread

Oh phooeey. Are you really trying to tell me that if I showed you a silhouette side view of a rider and took away the bicycle, wheels, sex and other clues (we would have to put them all on the same relative crank length to their height), just showing you how the rider fit on the bicycle, that you could tell me whether the rider was big, small, had a long or short femur or anything else from this information? I simply don't believe it. .

You are kidding right?

You are going to try this approach? I would therefore challenge YOU to look at photos of two riders (Brad and Tommy) and let us all know how you can be silly enough to claim that they are pretty much the same.

 

[Martin318is]

I am sorry that you felt my pointing out that I have been encouraging the reader to experiment with this since the very first post in a thread that now has over 800 replies was patronizing towards you.

This is just pathetic Frank. I made clear reference to several posts of yours that mocked the comprehension skills of contributors to this thread. Don't try to defend your poor behaviour by twisting my comment and trying to make it apply to the entire thread

 

[Martin318is]

Oh phooeey. Are you really trying to tell me that if I showed you a silhouette side view of a rider and took away the bicycle, wheels, sex and other clues (we would have to put them all on the same relative crank length to their height), just showing you how the rider fit on the bicycle, that you could tell me whether the rider was big, small, had a long or short femur or anything else from this information? I simply don't believe it. .

You are kidding right?

You are going to try this approach? I would therefore challenge YOU to look at photos of two riders (Brad and Tommy) and let us all know how you can be silly enough to claim that they are pretty much the same.

 

[Martin318is]

Don't bother replying Frank, I won't be coming back to this thread as it is clearly about you trying to appear more clever than everybody else.

 

[FrankDay]

I would therefore challenge YOU to look at photos of two riders (Brad and Tommy) and let us all know how you can be silly enough to claim that they are pretty much the same.

Putting my physician hat on now, this, in my opinion, is pretty silly. We are humans and we are all pretty much similar. Of course there are differences, but, IMHO, those differences are miniscule compared to say the differences found in a species that has been bred to maximize the potential anatomical variation, dogs for instance comparing a greyhound with a dachshund.

 

[lostintime]

Well Frank ..... any idea that is considered different and out of the realm of what some consider "normal" will meet resistance. . . and that's all much of this thread is. As mentioned numerous times ... anyone can buy a set of 110 BCD cranks from the likes of Sinz for example(down to 115mm) for $50. The greatest resistance comes usually from those that have never tried them in the first place ! ... and use any study they can find and other people's negative opinions to reinforce their resistance. That's okay and all ... it just needs to be seen for what it is.

We don't have to all use 110's .... and even the one's you documented didn't do this is one step... they did it gradually. If someone went straight from 175 to 110, yeah , the jump is so great you'd probably ditch them in a day or two. If you go in maybe 20mm increments or so you can give the body some and mind some time to adapt. When I first tried the 152's and went uphill ..... I thought .... I've lost some power...Oh crap! Well no .. I didn't really .... I've learned over the weeks that I can use my leverage even more effectively that could with longer cranks. Funny how that works. Combined with mid foot pedal position I experience less and less leg fatigue than with long cranks and tradition ball of the foot over the pedal.

You don't have to race or ride competitively to enjoy these benefits of a shorter crank too

 

[FrankDay]

Well Frank ..... any idea that is considered different and out of the realm of what some consider "normal" will meet resistance. . .

except the iphone

and that's all much of this thread is. As mentioned numerous times ... anyone can buy a set of 110 BCD cranks from the likes of Sinz for example(down to 115mm) for $50. The greatest resistance comes usually from those that have never tried them in the first place ! ... and use any study they can find and other people's negative opinions to reinforce their resistance. That's okay and all ... it just needs to be seen for what it is.

We don't have to all use 110's .... and even the one's you documented didn't do this is one step... they did it gradually. If someone went straight from 175 to 110, yeah , the jump is so great you'd probably ditch them in a day or two. If you go in maybe 20mm increments or so you can give the body some and mind some time to adapt. When I first tried the 152's and went uphill ..... I thought .... I've lost some power...Oh crap! Well no .. I didn't really .... I've learned over the weeks that I can use my leverage even more effectively that could with longer cranks. Funny how that works. Combined with mid foot pedal position I experience less and less leg fatigue than with long cranks and tradition ball of the foot over the pedal.

You don't have to race or ride competitively to enjoy these benefits of a shorter crank too

I agree completely. And, your post points out a potential weakness of any study along this line, that being whether the participant has had time to adjust to the new crank length before being tested. Adaption time may be critical to how one tests.

Anyhow, some of us are more "experimental" than others. Here is the latest facebook update from Drew.

58 mile R///DE El Cajon Lakeside Ramona and back. Good to be back in East County and felt incredibly good on the Jamis steel bike today. I am probably the only one on the planet riding 80mm powercranks with arch cleats. Will go down to 60 then return to 110mm probably. Having fun right now.

 

[FrankDay]

Another short crank experience report received today

I've been riding powercranks for a few months now and had them set at 150mm for a while. They felt absolutely fine, I could spin faster more easily and my power was good. But in order to make sure I was getting power numbers I was riding on the trainer exclusively. With the nice weather quickly fading away I wanted to get out on the road and felt I'd spent enough time on the short cranks to be comfortable. I set them to 140mm and took off. My cadence was even higher than at 150mm and I ripped along, easily getting up to 30mph on the flat and holding it there. I thought there might be a bit of a downhill and when I came back the same way I was still doing 27mph, so not much of a downgrade. I did notice that I had a bit of trouble climbing at 140mm, I charge partly to the novelty of that length and maybe to gearing as well. The last stretch on this jaunt was a slight downhill but only just and I was holding 33mph not only on the decline but also maintaining it on the flat until I needed to turn.

Now all of this was interesting and positive but the switch really flipped when I put that bike in the house and took out my road bike to head out on another ride. The bike with powercranks is understandably heavy, heavy wheels, not particularly light frame and heavy cranks. My road bike is an R3 at just over 15lbs with a compact 175mm crankset. The feeling when I first started out was incredible, as though I had to move my legs miles just to get them around the circle. The direct juxtaposition accentuated where the dead spaces were. I've ridden powercranks quite a bit and have had a number of people comment about how smooth my action is but right then I was feeling horribly clumsy and wishing for shorter. Not only was I feeling clumsy, I was feeling slow. On the same flat road I was doing 21 instead of the 24 I had been doing only minutes before on a bike weighing probably five or six pounds more.

 

[CoachFergie]

We had two High Performance Coaching presentations yesterday. One was evidence based and each slide was backed with data and references to where the data came from and how it was measured. There was little discussion and no argument as the basis for the presentation was very sound.

In the second presentation the guy started by saying his was an experience based presentation on strength training in cycling. He "believed" that strength training improved cycling (and is paid rather well to teach cyclists how to perform strength training). No data, no ability to link the strength in the gym to strength on the bike. Every coach there had their own opinions and no real consensus was achieved. Some got quite emotional and shared stories of how little johnnie improved his squat by 20kg and going from u15 to u17 lowered his 500m time by 2 seconds.

So all I see here is just more opinion and very little actual data. People feel that strength training makes them better riders, that nasal strips help them breathe better, that taking large amounts of anti-oxidants helps their adaptation to stressful training and that short cranks make them more powerful when the evidence from some well performed studies shows that these differences don't exist or in some areas are actually harmful.

Science is just a method that provides structure for how we measure data and report that data. Is it perfect, heck no, look at the Swart and Robinson papers on the "equalness" of heart rate monitors and power meters and the "claims" that a power meter should improve performance.

So this thread is 800+ posts and still no evidence of the "importance" of crank length.

Well Frank ..... any idea that is considered different and out of the realm of what some consider "normal" will meet resistance. . . and that's all much of this thread is. As mentioned numerous times ... anyone can buy a set of 110 BCD cranks from the likes of Sinz for example(down to 115mm) for $50. The greatest resistance comes usually from those that have never tried them in the first place ! ... and use any study they can find and other people's negative opinions to reinforce their resistance. That's okay and all ... it just needs to be seen for what it is.

We don't have to all use 110's .... and even the one's you documented didn't do this is one step... they did it gradually. If someone went straight from 175 to 110, yeah , the jump is so great you'd probably ditch them in a day or two. If you go in maybe 20mm increments or so you can give the body some and mind some time to adapt. When I first tried the 152's and went uphill ..... I thought .... I've lost some power...Oh crap! Well no .. I didn't really .... I've learned over the weeks that I can use my leverage even more effectively that could with longer cranks. Funny how that works. Combined with mid foot pedal position I experience less and less leg fatigue than with long cranks and tradition ball of the foot over the pedal.

You don't have to race or ride competitively to enjoy these benefits of a shorter crank too

 

[CoachFergie]

My "news" from Alice whose father brought her a power meter with longer cranks. Last week she won her first New Zealand road title in a road race breaking away with another girl I coach. This weekend she won a stage of the Yunca Tour in the U17 girls grade. After the change to a longer crank she is producing more power and has recently set some very encouraging power PBs.

Is it the change in crank length?
Is it the change in training?
Is it my awesome coaching?
Was it how we were able to get her torso more horizontal and improve aerodynamics?
Is it using a power meter has improved her performance?
Was she wearing "lucky red socks"?

I have several other cyclists who race and train with a power meter who are making real gains in their power who haven't changed their crank length. I can supply real data to support this.

 

[Oldman]

Really! And your evidence for this statement?

12000 miles a year for 25 years in the company of riders using every kind of equipment, position and strength level. Since you don't count that as "data" unless you have witnessed it yourself it holds no value to your argument/product endorsement.

As for a "round" pedal stroke you only need to watch video of any good TT rider at top speed. My definition may be awkward to you but they maximize power throughout the pedalstroke.

 

[Oldman]

The science that has been conducted on pedal forces shows this not to be the case.

Or perhaps I misunderstand what you mean by "round stroke" or what you mean needs better definition.


Just checking (as I'm not sure whether you are saying BMX do or do not run short cranks).

In BMX (professional) it is far more common for cranks used to be longer than a typical roadie uses. 180mm or longer.

Actually on item BMX you are correct, and not. Some old school BMXers I knew favored short cranks and were generally good track sprinters. They did not like longer, tough races. Another liked long cranks and spun them, even in TTs and was phenomenal. I was at a loss to explain his efficiency by looking at him. Most of the real young BMXers like shorter cranks in my neighborhood.
It generally reinforces my opinion that for quick and shorter efforts a shorter crank allows for acceleration. Longer, power based efforts are better served by longer cranks but it does seem to be individual and a product of habit. The constant is that really, really good TTers don't ride short cranks.

 

[FrankDay]

The constant is that really, really good TTers don't ride short cranks.

I don't know is that is true or not. However, even if it is, that is not evidence that they are using the optimum crank length for them.

 

[onetrack]

So this thread is 800+ posts and still no evidence of the "importance" of crank length.

No evidence

perhaps not the evidence you prefer

personal experience is plenty

Tell us again how much personal experience you have with very short cranks.

 

[acoggan]

Tell us again how much personal experience you have with very short cranks.

Well if you're looking for anecdotes (vs. scientific data): I've tested lengths as short as 148 mm (obtained by having a 170 mm crank shorted by this guy: http://bikesmithdesign.com/index.html). In a rather extreme aero position, they allowed my produce an extra 5 W compared to using 170 mm cranks in that same position. However, the reduction in drag wasn't enough to compensate for the loss of power vs. a higher position, so I've gone back to using 170 mm. (Note: I've also tested 165 mm cranks in the same positions.)

 

[onetrack]

Actually on item BMX you are correct, and not. Some old school BMXers I knew favored short cranks and were generally good track sprinters. They did not like longer, tough races. Another liked long cranks and spun them, even in TTs and was phenomenal. I was at a loss to explain his efficiency by looking at him. Most of the real young BMXers like shorter cranks in my neighborhood.
It generally reinforces my opinion that for quick and shorter efforts a shorter crank allows for acceleration. Longer, power based efforts are better served by longer cranks but it does seem to be individual and a product of habit. The constant is that really, really good TTers don't ride short cranks.

I'm not sure how little kids dirt jump racing fits into this conversation. Just so we are on the same page, I'm talking about maximizing the performance of competitive adults on road bikes, and maximizing the comfort and endurance of touring adults on road bikes.

Your statement shows that crank length is not considered a variable at this point

Imagine if people experimented with crank length

what would people find

would the "really really" good time trialers still be on 177.5mm cranks

Why wait for people to beat you before trying this out

It costs less than one tire to try this out. why not

 

[FrankDay]

Well if you're looking for anecdotes (vs. scientific data): I've tested lengths as short as 148 mm (obtained by having a 170 mm crank shorted by this guy: http://bikesmithdesign.com/index.html). In a rather extreme aero position, they allowed my produce an extra 5 W compared to using 170 mm cranks in that same position. However, the reduction in drag wasn't enough to compensate for the loss of power vs. a higher position, so I've gone back to using 170 mm. (Note: I've also tested 165 mm cranks in the same positions.)

You got an "extra" 5 watts from shorter cranks but you thought this didn't compensate from the "extra drag" you got from the "higher position"? Could you explain this higher position and this extra drag? Makes no sense to me. More detail please?

 

[onetrack]

Well if you're looking for anecdotes (vs. scientific data): I've tested lengths as short as 148 mm (obtained by having a 170 mm crank shorted by this guy: http://bikesmithdesign.com/index.html). In a rather extreme aero position, they allowed my produce an extra 5 W compared to using 170 mm cranks in that same position. However, the reduction in drag wasn't enough to compensate for the loss of power vs. a higher position, so I've gone back to using 170 mm. (Note: I've also tested 165 mm cranks in the same positions.)

so, if I'm understanding you correctly. In an aero position you make more power on 148mm cranks. But overall you made the most power in a more upright position. Did you test the shorter cranks in a more upright position?

After the cyclocross season is done, I will be testing my wattage at several lengths to see what length I should be training/road racing with next season. Should be enlightening.

 

[onetrack]

You got an "extra" 5 watts from shorter cranks but you thought this didn't compensate from the "extra drag" you got from the "higher position"? Could you explain this higher position and this extra drag? Makes no sense to me. More detail please?

I think he's saying overall there is a wattage drop going into the " rather extreme aero position" that short cranks can't overcome (though he can squeeze out another 5).

 

[Oldman]

I'm not sure how little kids dirt jump racing fits into this conversation. Just so we are on the same page, I'm talking about maximizing the performance of competitive adults on road bikes, and maximizing the comfort and endurance of touring adults on road bikes.

Your statement shows that crank length is considered a variable at this point

Imagine if people experimented with crank length

what would people find

would the "really really" good time trialers still be on 177.5mm cranks

Why wait for people to beat you before trying this out

It costs less than one tire to try this out. why not

All of these quality riders did experiment with crank length. If you read my posts you'd know that and many have had the benefit of huge research budgets.

They found out the optimum crank for each type of race. Note I said "type" of race; they often use different lengths for different terrain.
Most really good TTers are on 170 to 175mm cranks unless they are well over 6'.

I'll match my results against yours any time. 52:20 40km at 45 years of age and not a pro. 135lbs body weight.

 

[FrankDay]

All of these quality riders did experiment with crank length.

Your evidence for the kind of experimenting they did and the results?