You need 220's at least.

who makes a longer crank? who sells them?

hey bud.. got the email..
i thought you were on 177.5's.. i'd look into 180's minimum.. (i think thats the largest "normal" lenght crank out there)
-dave

Here ya go!

http://www.zinncycles.com/cranks.aspx

http://www.machinehead-software.co.uk/...anks/crank_calc.html

I'm 6'9" and switched to Zinn cranks last year on my custom Litespeed. 210's, major difference. I will NEVER go back to shorter cranks. However, keep in mind, on a custom bike you can ask the builder to raise the bottom bracket height so that when the pedal is in the 6 o'clock position it's the same height off the ground as a normal setup. If you go with cranks too long on a standard bike you run the risk of scraping your pedal in a turn.

Like somebody mentioned, zinncycles.com, Lennard has a pretty lengthy article explaining why and how to get a ballpark figure for your ideal crank length.

He's also in the process of changing the design on his cranks from a square taper bottom bracket design to an integrated spindle design with outboard bearings which will make the cranks more stiff.

They worked for me, I was in the top 5% of bike splits in every triathlon I raced last season (about 9 sprint and olympic distance events), and I'm 100% Clydesdale.

high sierra cycle center also sells a longer crankarm that look suspiciously like the zinn cranks. I have a pair that work great on my mountain bike.

http://www.hscycle.com/.../customcrankset.html

Crank arm length is largely irrelevant with adaptation.

-SD

...I know I'm getting flamed with this one.

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https://www.kickstarter.com/...bike-for-the-new-era

[reply]Crank arm length is largely irrelevant with adaptation.

-SD

...I know I'm getting flamed with this one.[/reply]

Agreed, 100%!!! I rode a bike with 170 on one side and 175 on the other for a year and had no idea!

you aren't supposed to agree, my chances are shot as well as your credibility as a D.A.

-SD

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https://www.kickstarter.com/...bike-for-the-new-era

[reply]you aren't supposed to agree, my chances are shot as well as your credibility as a D.A.

-SD[/reply]

As you can imagine, my response would be: like I could give a rat's ass ;-)

5 mm isn't that relevant, but 25 mm is very relevant.

I would agree that 5mm either way is probably irrelevant, but 20mm is significant. My guess is, the people who say crankarm length is irrelevant probably fall in that 80 percent of the population for which a 170mm to 175mm crankarm is largely sufficient to do the job. Component companies make arm lengths to suit that group and thus is born the idea that it doesn't really matter much.

I would be interested to know the range of crankarm lengths with which you have experimented that gives credence to your statement.

Chad

subjects tested at the OTC from 145mm to 190mm, less than 4% variance in peak and sustained power output, results also uncovered a greater relationship to q factor variance than crank length

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https://www.kickstarter.com/...bike-for-the-new-era

"Agreed, 100%!!! I rode a bike with 170 on one side and 175 on the other for a year and had no idea!"

How could you not feel a difference???

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�The greater danger for most of us is not that our aim is too high and we miss it, but that it is too low and we reach it.� -Michelangelo

MoodBoost Drink : Mood Support + Energy.

[reply]"Agreed, 100%!!! I rode a bike with 170 on one side and 175 on the other for a year and had no idea!"

How could you not feel a difference???[/reply]

I can't explain why I couldn't, just that I didn't know until the following winter when my mechanic pointed it out!

subjects tested at the OTC from 145mm to 190mm, less than 4% variance in peak and sustained power output, results also uncovered a greater relationship to q factor variance than crank length

And that is what you based your statement on? I love how someone comes up with a study and then other people treat it as gospel.

Did the study address the possibility that different size people will do better with different size crankarms? Did the study allow the subjects to become adapted to riding with each of the different length crankarms? Just those two items demonstrate that any type of exhaustive study on the issue is nearly impossible.

Leonard Zinn probably knows as much as anyone on the subject and he said this:

I published some crank-length tests in VeloNews in 1995 and 1996. These tests were either inconclusive or seemed to indicate that all riders, regardless of size, put out more maximum power with super-long (220mm) cranks, and that all riders had lower heart rates at low power outputs with super-short cranks (100 to 130mm). My experimental method in these tests was lacking in those tests, but I was simply not willing to stop there, since I knew from personal experience that increasing crank length for a tall rider like myself (6’6”) makes a difference. It also made sense to me that there must be a limitation dependent on rider size for how long you can go. Since then, I have continued to experiment, beginning by using the range of cranks that Bruce Boone built for those 1996 tests (eight cranks, evenly spaced between 100mm and 220mm) and of these eight, I found that I was most happy with 202.3mm cranks. For at least three years now, I have been riding 200mm and find that I not only like them, but that I am considerably faster on the nearby, approximately half-hour climb up Flasgstaff mountain west of Boulder that I do frequently with a stopwatch.

Thus encouraged, I have conducted other crank studies ever since. However, in understanding what went wrong in those 1995 and 1996 tests, I developed higher standards for what constitutes a publishable test, and my subsequent tests still have not met that standard, mostly due to having too few subjects (often just me and a couple of other riders). Too bad, because I have put a lot of time and effort into a number of them! It is one thing if you are a physiology researcher trained and funded to do these sorts of studies. It is not easy to do a test in which you eliminate all other variables besides crank length. It requires lots of time, planning, willing (read, paid) subjects and equipment. It’s hardly the type of thing that is realistic to undertake with no budget in order to write one article for a cycling magazine that still expects an article from me on something else every two weeks as well. Anyway, I have conducted all of these recent tests on the road with tall riders (6’5” and over) because it was simpler and cheaper to use my personal stable of bikes than to always be switching cranks on other people’s bikes. By being willing to take my custom crank recommendations, my tall custom frame customers have also have graciously acted as test subjects. Besides having data showing people going faster and generating more power on my own personal bikes, it is hard to deny it when you have many people raving about how much more comfortable, natural and powerful they feel on cranks proportional to their leg length. On mountain bikes, tall customers report being able to smoothly power over obstacles they could not have before. They also report liking the longer, more stable stance when coasting downhill over technical obstacles. And the higher bottom bracket I build into the frame makes hitting the chainrings on logs and the like almost impossible (especially with 29-inch wheels), yet the rider’s center of gravity is no higher (since the bottom foot is still the same height above the ground due to the longer crank).

The results indicate clearly enough to me that crank length must be proportional to rider size in some way. Whether you decide it is proportional to leg length, thigh length, overall height or something else is a minor point. The same goes for what you think the constant of proportionality should be. It could be something different from 0.21 or 0.216, but whatever it is, it will indicate for a lot of people that they should be using a vastly different length than they are. That is the part that is hard to accept for a lot of people. No matter our size, we are by and large all stuck on cranks of the same length. The 3% difference between a 170mm and a 175mm hardly constitutes a length choice, and the 180mm you can find in only top-end component groups still does not broaden the range much. Accepting that cranks should be scaled up or down with rider size opens up a whole can of worms that a lot of riders, bikes-shop personnel and component companies would just as soon stayed closed. Obviously, economies of scale of producing cranks go out the window if you have to supply a range from say, 140mm to 220mm, and a bike shop’s inventory costs go way up to stock a lot more lengths as well. The same goes for bike frames; if a manufacturer increases the bottom bracket height with every increase in frame size in order to accommodate crank arms proportional to the size of the rider, its costs and complexity of frame jigs goes up, and the staff training and inventory costs for bike shops goes up as well.

There are obvious practical reasons to stick with the status quo. Those may have to do with what is best for the pocketbooks of consumers, bike shops, and manufacturers, but not what is best for the rider’s performance and comfort.

no, that is not the only evidence I based my statement on. I've spoken to Zinn on the subject. I've got my own experience and that of others, and I simply choose to believe that for the most part; with adaptation, it is irrelevant.

Distance from your navel to the ground, while barefoot and flatfooted, and of course while standing as upright as you possibly know how.

Take that dimension and divide it by pi (3.14159...)

Now take that and divide by 2.

Simplicity.