The importance of crank length to the cyclist.

[FrankDay]

I think I'm understanding you correctly, Frank. But I have a question. If you are already riding comfortably with a flat back on long (175) crank arms, then wouldn't raising the saddle (for the shorter arms) effectively make one less aero?

Can you direct me to that video you are referring to? I an't seem to find it.
Thanks.

For that rider "already riding comfortably with a flat back on long (175) crank arms", unless the head is already below the highest point of the back/**** it is pretty unlikely that raising the seat and **** will increase the frontal area and make one less aero. The frontal area is not going to increase unless the **** is moved out of the wind shadow of the trunk/shoulders. The number of people for whom this condition currently exists is, I would estimate, approximately zero but I would give you that it is theoretically possible. I guess that is why one needs to try it and see if it works for you or not.

Here is the link to the video i made: http://www.youtube.com/watch?v=HFxBg7BnFlQ

Frank

 

[Boeing]

Because of the interest we have seen in short cranks and because of the number of PC'ers who have decided to race on shorter PC's this year we have decided to come up with a short PC for racing. These are available from sizes ranging from 142.5. to 75 mm. Pictured is my own 105 mm cranks mounted on my bicycle with compact 50/34 chain rings. Within the next month or so I will have available shorter cranks of the "regular crank" variety for those who don't give a whoot(sp?) about pedaling in the PC fashion but see an advantage to shorter cranks. While short cranks are available though other sources, the shown crankarm itself weighs about 140 gm but we expect our fixed crank arms should weigh about 100 gms (depending upon the length) for the weight weenies, when available. Also note the picture shows the spider being made out of a soon to be available composite material in the final stages of testing for further weight reduction. Enjoy.

this must be that custom bike built for the actor who plays Tyrione Lannister

 

[Maxiton]

So what did we decide about crank length?

 

[CoachFergie]

Varying definitions of importance.

 

[simo1733]

Because of the interest we have seen in short cranks and because of the number of PC'ers who have decided to race on shorter PC's this year we have decided to come up with a short PC for racing. These are available from sizes ranging from 142.5. to 75 mm. Pictured is my own 105 mm cranks mounted on my bicycle with compact 50/34 chain rings. Within the next month or so I will have available shorter cranks of the "regular crank" variety for those who don't give a whoot(sp?) about pedaling in the PC fashion but see an advantage to shorter cranks. While short cranks are available though other sources, the shown crankarm itself weighs about 140 gm but we expect our fixed crank arms should weigh about 100 gms (depending upon the length) for the weight weenies, when available. Also note the picture shows the spider being made out of a soon to be available composite material in the final stages of testing for further weight reduction. Enjoy.
https://fbcdn-sphotos-a.akamaihd.net/hphotos-ak-ash4/p480x480/431614_10150688725135126_619090125_11812337_9655569
58_n.jpg

Do you have difficulty putting your foot down when you unclip?

 

[FrankDay]

Do you have difficulty putting your foot down when you unclip?

No. I do have to come off the saddle but it has never been something I even thought about.

Edit: I have been told that there is one Italian frame maker who is now making frames with lower BB's specifically for shorter cranks.

 

[coapman]

Because of the interest we have seen in short cranks and because of the number of PC'ers who have decided to race on shorter PC's this year we have decided to come up with a short PC for racing. These are available from sizes ranging from 142.5. to 75 mm. Pictured is my own 105 mm cranks mounted on my bicycle with compact 50/34 chain rings. Within the next month or so I will have available shorter cranks of the "regular crank" variety for those who don't give a whoot(sp?) about pedaling in the PC fashion but see an advantage to shorter cranks. While short cranks are available though other sources, the shown crankarm itself weighs about 140 gm but we expect our fixed crank arms should weigh about 100 gms (depending upon the length) for the weight weenies, when available. Also note the picture shows the spider being made out of a soon to be available composite material in the final stages of testing for further weight reduction. Enjoy.

Latest research from Australia confirms PC's do not increase power output.

 

[FrankDay]

Latest research from Australia confirms PC's do not increase power output.

First, your post is off topic.

Second, because you brought it up. Do you have a link to something new or only to the same old inadequate studies of the past?

 

[CoachFergie]

They are very good studies published in better journals. Pity the marketer of the product in question doesn't like the outcomes.

To bring this back on topic; any real data of the "importance" of crank length? Just for those who want more than meaningless stories!

 

[fasthill]

Short cranks save whales.

 

[Boeing]

Because of the interest we have seen in short cranks and because of the number of PC'ers who have decided to race on shorter PC's this year we have decided to come up with a short PC for racing. These are available from sizes ranging from 142.5. to 75 mm. Pictured is my own 105 mm cranks mounted on my bicycle with compact 50/34 chain rings. Within the next month or so I will have available shorter cranks of the "regular crank" variety for those who don't give a whoot(sp?) about pedaling in the PC fashion but see an advantage to shorter cranks. While short cranks are available though other sources, the shown crankarm itself weighs about 140 gm but we expect our fixed crank arms should weigh about 100 gms (depending upon the length) for the weight weenies, when available. Also note the picture shows the spider being made out of a soon to be available composite material in the final stages of testing for further weight reduction. Enjoy.

Frank

I am not sure this image helps your argument much. the frame and wheels set look to be a hybrid comfort bike. What are those tyres like 42mm? Unless this is an argument for comfort

 

[BroDeal]

So what did we decide about crank length?

We decided that this entire thread was created by Day to promote his upcoming short crank product by posting a combination of anecdotes and mumbo jumbo that would not pass muster in a kindergarten science hour. Instead of buying ads on CN, he decided that the cheap way to get publicity is to spam forums by finding someone he can bicker with endlessly. In his mind, standing behind outrageous and often flat out fraudulent claims for benefits of his product, so outrageous that people laugh when they read them, is a smart way advertise. It is why he and his snake oil product has become the butt of jokes on pretty much every cycling and triathlon forum on the net.

Open your wallet and buy some ads, Day.

 

[blutto]

We decided that this entire thread was created by Day to promote his upcoming short crank product by posting a combination of anecdotes and mumbo jumbo that would not pass muster in a kindergarten science hour. Instead of buying ads on CN, he decided that the cheap way to get publicity is to spam forums by finding someone he can bicker with endlessly. In his mind, standing behind outrageous and often flat out fraudulent claims for benefits of his product, so outrageous that people laugh when they read them, is a smart way advertise. It is why he has been banned on pretty much every cycling and triathlon forum on the net.

Open your wallet and buy some ads, Day.

....what a sad tale of woe made only worse by the fact the most esteemed and decorated CoachFergie has been used as a hapless dupe ( or as doctrinaire Marxists would say, a useful idiot ....not of course to imply that the injured party is an idiot in the colloquial sense...or for that matter, in any way useful ...outside of Frank's very slick marketing scheme...)...

....so Frank was not only slogging his wears but concurrently slagging his mortal enemy who unfortunately for us fans happens to be an honoured member of this forum..sad, very sad...though I suppose in the strictest of terms, as defined by The Magic of The Marketplace Handbook, that was a mighty fine bit of multi-tasking....

Cheers

blutto

 

[BroDeal]

 

[Boeing]

They are very good studies published in better journals. Pity the marketer of the product in question doesn't like the outcomes.

To bring this back on topic; any real data of the "importance" of crank length? Just for those who want more than meaningless stories!

on topic I dont disagree with you here.

however this is like the hub calling the rim round.

I support fallacy free threads

 

[Martin318is]

I'm just laughing at the fact this thread is still running. There are roughly 3 salient points on each side of the discussion, after which this entire discussion is about powercranks.

Frank (and Fergie, et al) how about discussing ONLY the crank length and leaving the product placement out of it? Clearly, if a particular crank length IS important to a cyclist, the brand of crank that gets them there is irrelevant.

 

[FrankDay]

I'm just laughing at the fact this thread is still running. There are roughly 3 salient points on each side of the discussion, after which this entire discussion is about powercranks.

Frank (and Fergie, et al) how about discussing ONLY the crank length and leaving the product placement out of it? Clearly, if a particular crank length IS important to a cyclist, the brand of crank that gets them there is irrelevant.

If the entire discussion beyond the three salient points has been entirely about PowerCranks it has not been of my doing. I am convinced that everyone can benefit from going to shorter cranks regardless of whether they use or train with PowerCranks or not.

PowerCranks may come into this discussion peripherally though. Martin, in his study, found power maximized at crank length of 145 mm. The people who are reporting testing results to me are finding power maximizing somewhere between 100 and 120 mm crank length. (I just got another report from someone doing testing on 145 cranks but I am withholding it because he intends to repeat the testing twice more, a week apart, on 125 and 105 cranks, and I would like to present the complete results.) This is substantially shorter than the results reported by Martin. But, all of these people reporting to me are doing their testing on PowerCranks so it may be that how short one can go before losing power may depend upon their pedaling technique. Or, of course, there might be another explanation. We simply don't have enough data to know.

What boggles my mind though is how Martin could look at his data and determine that crank length doesn't make any difference when it was clear his data tended to say something different but his cohort was too small to reach statistical significance, and many of you blindly accept his proclamation as fact and come here and accuse me, because I raise the point, of doing so solely to sell product. There are lots of sources for short cranks. No one is going to buy mine unless they are also interested in the PowerCranks concept.

Why so many of you are afraid of a discussion about a topic that is outside of your own personal experience is another mystery. Loosen up.

 

[Boeing]

For what it is worth I sized down from a 177.5 to a 175

 

[BroDeal]

For what it is worth I sized down from a 177.5 to a 175

Bro, you should have lopped a hundred millimeters off of that, not 2.5. Your power would have increased by 40% or whatever number Frank is pulling out of his butt today. How much you can trust power numbers from a man who was once caught using a doctored power file to argue his case on Slowtwitch I don't know, but if you get even half of the phony numbers that Day reports for his snake oil products then you'll be killing it.

 

[42x16ss]

If the entire discussion beyond the three salient points has been entirely about PowerCranks it has not been of my doing. I am convinced that everyone can benefit from going to shorter cranks regardless of whether they use or train with PowerCranks or not.

PowerCranks may come into this discussion peripherally though. Martin, in his study, found power maximized at crank length of 145 mm. The people who are reporting testing results to me are finding power maximizing somewhere between 100 and 120 mm crank length. (I just got another report from someone doing testing on 145 cranks but I am withholding it because he intends to repeat the testing twice more, a week apart, on 125 and 105 cranks, and I would like to present the complete results.) This is substantially shorter than the results reported by Martin. But, all of these people reporting to me are doing their testing on PowerCranks so it may be that how short one can go before losing power may depend upon their pedaling technique. Or, of course, there might be another explanation. We simply don't have enough data to know.

What boggles my mind though is how Martin could look at his data and determine that crank length doesn't make any difference when it was clear his data tended to say something different but his cohort was too small to reach statistical significance, and many of you blindly accept his proclamation as fact and come here and accuse me, because I raise the point, of doing so solely to sell product. There are lots of sources for short cranks. No one is going to buy mine unless they are also interested in the PowerCranks concept.

Why so many of you are afraid of a discussion about a topic that is outside of your own personal experience is another mystery. Loosen up.

But I thought that power measurements and analysis was only for people trying to justify their jobs.....

 

[42x16ss]

Bro, you should have lopped a hundred millimeteres off of that, not 2.5. Your power would have increased by 40% or whatever number Frank is pulling out of his butt today. How much you can trust power numbers from a man who was once caught using a doctored power file to argue his case on Slowtwitch I don't know, but if you get even half of the phony numbers that Day reports for his snake oil products then you'll be killing it.

Really??? That's hilarious coming from someone who refuses to even consider using a PM (Frank not you)

 

[Boeing]

Bro, you should have lopped a hundred millimeteres off of that, not 2.5. Your power would have increased by 40% or whatever number Frank is pulling out of his butt today. How much you can trust power numbers from a man who was once caught using a doctored power file to argue his case on Slowtwitch I don't know, but if you get even half of the phony numbers that Day reports for his snake oil products then you'll be killing it.

well I can say that before the switch I was farsighted but after about 300 miles I am back to 20/20 vision. 2.5mm helped I might be able to see through walls if only coachfargo was here in cali shouting through a bull horn to go faster

 

[Tapeworm]

...What boggles my mind though is how Martin could look at his data and determine that crank length doesn't make any difference when it was clear his data tended to say something different but his cohort was too small to reach statistical significance, and many of you blindly accept his proclamation as fact and come here and accuse me, because I raise the point, of doing so solely to sell product...

Maybe because Martin IS a scientist and not a salesman and understood very clearly the data he had obtained. And he is NOT in the business of selling cranks, Power or otherwise? Thankfully you can interpret this for us Frank.

 

[Martin318is]

If the entire discussion beyond the three salient points has been entirely about PowerCranks it has not been of my doing. I am convinced that everyone can benefit from going to shorter cranks regardless of whether they use or train with PowerCranks or not.

PowerCranks may come into this discussion peripherally though. Martin, in his study, found power maximized at crank length of 145 mm. The people who are reporting testing results to me are finding power maximizing somewhere between 100 and 120 mm crank length. (I just got another report from someone doing testing on 145 cranks but I am withholding it because he intends to repeat the testing twice more, a week apart, on 125 and 105 cranks, and I would like to present the complete results.) This is substantially shorter than the results reported by Martin. But, all of these people reporting to me are doing their testing on PowerCranks so it may be that how short one can go before losing power may depend upon their pedaling technique. Or, of course, there might be another explanation. We simply don't have enough data to know.

What boggles my mind though is how Martin could look at his data and determine that crank length doesn't make any difference when it was clear his data tended to say something different but his cohort was too small to reach statistical significance, and many of you blindly accept his proclamation as fact and come here and accuse me, because I raise the point, of doing so solely to sell product. There are lots of sources for short cranks. No one is going to buy mine unless they are also interested in the PowerCranks concept.

Why so many of you are afraid of a discussion about a topic that is outside of your own personal experience is another mystery. Loosen up.

and once again around the drain we go. My point was very simple and clear Frank, IF there are indeed benefits to riding a particular length of crank, by definition, that benefit must be independant of the brand of the crank - otherwise what you are saying is that length X MYBRAND cranks work better than standard length normal cranks.

Which is a different question

 

[Martin318is]

Why so many of you are afraid of a discussion about a topic that is outside of your own personal experience is another mystery. Loosen up.

Nobody is afraid of discussing the topic Frank. Everything useful there was to say on the topic came out inside the first 100 posts. After that, it has been stuck in a rather boring and sad loop.

It is blatantly obvious that neither yourself nor several others will ever change your positions on the topic, therefore making this not so much a discussion, more a shouting match of paliamentary proportions.

Come up with a new angle or just let the thread die the death it has been begging for.

Albert Einstein
Insanity: doing the same thing over and over again and expecting different results.