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Does somene produce cranks that are 180mm (or more) at price level below DA/Record?
It seems that in Shimano and Campy groups only top-level have 180mm option. And what with other manufacturers?
 

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al0 said:
Does somene produce cranks that are 180mm (or more) at price level below DA/Record?
It seems that in Shimano and Campy groups only top-level have 180mm option. And what with other manufacturers?
Campy Record is not really that expensive, especially when compared to their new carbon cranks, which really occupy Campy's "top-level". All told, with a Chorus BB, you're looking at about $250. I just bought - new from an eBay store - some 180 mm Record for $195. Add that to a new Record BB for $31, also from eBay, and you're talking about half the price of DA, and way less than some goofy Lennard Zinn specials. Not quite the price of Centaur, but still a pretty good price. The store I bought my 180s from still has a new set of 177.5 mm. Let me know if you want me to find the link.

AEBike has Campy Record cranks for about $180, but QBP is sold out of both 177.5 and 180 until mid-February.

Profile makes BMX three-piece cro-mo cranks in any length from 135 to 210, for what it's worth. They'll weight more than your frame, but...
 

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gastarbeiter
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have you emailed the seller to check if they'd make an exception? it's worked for me in the past.

al0 said:
Thank you. But delivery only within US and I'm outside:(
 

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al0 said:
Does somene produce cranks that are 180mm (or more) at price level below DA/Record?
It seems that in Shimano and Campy groups only top-level have 180mm option. And what with other manufacturers?
How tall are you?

You must be over 7'!
 

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ultimobici said:
You must be over 7'!
Are you retarded?

Measure your inseam very carefully and go find the crank-length-finder-ratio. According to Lennard Zinn, the number is .216 x inseam in mm. (That's your EXACT inseam. Not the one you use at the Gap.) It's somewhat arbitrary, but you'll be surprised to find that the 170-175mm range only fits a small portion of most people. (Chances are, it doesn't fit you!)

Also, take note of how many singlespeeders - most or all shorter than seven feet - use 180 mm cranks for a bit of extra leverage.

In fact, just go read this:

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

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SDizzle said:
Are you retarded?

Measure your inseam very carefully and go find the crank-length-finder-ratio. According to Lennard Zinn, the number is .216 x inseam in mm. (That's your EXACT inseam. Not the one you use at the Gap.) It's somewhat arbitrary, but you'll be surprised to find that the 170-175mm range only fits a small portion of most people. (Chances are, it doesn't fit you!)

Also, take note of how many singlespeeders - most or all shorter than seven feet - use 180 mm cranks for a bit of extra leverage.

In fact, just go read this:

http://www.zinncycles.com/cranks.aspx
Thanks I've just checked it out and I should be on 180mm cranks.

I'm 5'10" with a 830mm inseam. My thigh length is long for my leg length. The Hinault method suggested I could use 175mm, but they gave me sore knees, so I stayed on 172.5mm.

Well I have been using the 200mm cranks now for a few weeks and I love them…I saw immediate improvements in power on the flat and especially in climbing…On my old 180mm cranks I used the traditional 39 / 53 chain-ring combo but I have now changed to 44 / 56 and find that where I used to ride comfortably in the 39 x 15 on my easy days, I now feel like I am using the same effort (and the same cadence) in the 44 x 15…but obviously riding measurably faster…I have not needed bigger than the 21t where I frequently need to bail out to the 25t on steep pitches…as far as power is concerned, on the same hill where I used to struggle to hold 320 watts for 30 mins (3.2 watts/ kilo) I can now hold 410 (4.1 watts / kilo), this is probably the most significant measure of success here…
If Zinn is right, why is it no Professional is using bigger than 180mm? I know there are sponsor constraints, but I suspect if Jan Ullrich wanted 180mm+ he'd get them.
 

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ultimobici said:
If Zinn is right, why is it no Professional is using bigger than 180mm? I know there are sponsor constraints, but I suspect if Jan Ullrich wanted 180mm+ he'd get them.
I agree. I think crank length is one of the cycling industry's great oversights.

I read an article on CN not too long ago that had a close-up of Ullirich's 180mm DA crank, and the caption read something akin to, "maybe he'd be able to keep his cadence up if he ran shorter cranks..."
 

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Retardation

The "logic" of "crank length should be proportional to leg measurements" has been around for a LONG time, and lots of people have turned that "logic" into a formula for determining crank length. Only one problem: the research doesn't support it. Don't you just hate it when the data doesn't support the theory? One key feature that is often ignored in these discussions is the duration of muscle contraction that is controlled by cadence. It just may be that there is an optimum here, which is why there is a fairly narrow range of cadence for optimum performance. Longer cranks mean lower cadence, moving you out of that optimum range. Crank length has been a point of debate since the introduction of the "safety" bicycle in the late 1800s, and there have been all sorts of fads in that regard. Do you think that we have standardized on this narrow range because of some sort of global conspiracy, or because well over 100 years of experience (and testing the limits) have repeated shown that the 170-180 mm is really what works for human beings?

There is no reliable formula for predicting crank length. There ARE lots of formulas out there, but they are just figments of the imagination of their purveyors. No one has ever done a study that shows how crank length should relate to anything. Probably the best work done on this VERY difficult to research topic was by Lennard Zinn. He unintentionally showed how our adaptability was more important than our size or riding style. He's sure that the results of his study are wrong, but he just can't seem to find any data to support his pre-conceptions.

You will find no high quality data to support any particular crank length as being better than any other. This is true whether or not you correct for leg length, femur length, etc. On the other hand, you will find lots of anecdotal or low quality data to support all kinds of conclusions, and more theories than you can shake a stick at. A rider's response to changes in crank length is 1) highly individual, 2) dependent on riding style and the event (TT, climbing, crits, track racing, etc.), and 3) most important, highly adaptive. This is why it is so hard to study the effect of crank length.

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Fred Matheny Summary: There have been studies of crankarm length, but the results aren't consistent. Some show that longer cranks provide greater leverage for turning big gears. Some show that shorter cranks foster greater speed via a faster cadence. And some show that crank length is completely individual.

So, longer crankarms aren't a panacea for time trialing. In fact, there are dangers associated with them. The added length makes your knees bend more at the top of pedal strokes and extend more at the bottom -- both of which can lead to biomechanical injuries if you jump from 170 mm to, say, 180 mm.

Also, longer cranks reduce cadence -- and a brisk cadence is the key to good time trialing.

All this said, many time trialists use crankarms 2.5 mm longer than those on their normal road bike. Because 2.5 mm (one-tenth of an inch) isn't much, it rarely causes an injury. But the jury is still out on whether that bit of extra length actually improves performance.
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n00bsauce
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There's lots of mountain bike SS riders that use 180mm crank arms but they also usually stand when climbing. This makes using 180 arms much easier on the knees. For road riding I'd be very hesitant to use 180's because so much more of the grinding is done in the saddle and knee problems are much more likely.
 

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That's sort of what this says, I guess. At least, humans can adapt to different lengths with similar results.

This study exploited the alterations in pedal speed and joints kinematics elicited by changing crank length (CL) to test how altered task mechanics during cycling will modulate the muscle activation characteristics in human rectus femoris (RF), biceps femoris long head (BF), soleus (SOL) and tibialis anterior (TA). Kinetic (torque), kinematic (joint angle) and muscle activity (EMG) data were recorded simultaneously from both legs of 10 healthy adults (aged 20–38 years) during steady-state cycling at ~60 rpm and 90–100 W with three symmetrical CLs (155 mm, 175 mm and 195 mm). The CL elongation (ΔCL) resulted in similar increases in the knee joint angles and angular velocities during extension and flexion, whilst the ankle joint kinematics was significantly influenced only during extension. ΔCL resulted in significantly reduced amplitude and prolonged duration of BF EMG, increased mean SOL and TA EMG amplitudes, and shortened SOL activity time. RF activation parameters and TA activity duration were not significantly affected by ΔCL. Thus total SOL and RF EMG activities were similar with different CLs, presumably enabling steady power output during extension. Higher pedal speeds demand an increased total TA EMG activity and decreased total BF activity to propel the leg through flexion into extension with a greater degree of control over joint stability. We concluded that the proprioceptive information about the changes in the cycling kinematics is used by central neural structures to adapt the activation parameters of the individual muscles to the kinetic demands of the ongoing movement, depending on their biomechanical function.

But there is a dearth of research. (EBSCO returned three hits, and one concerned asymetrical left-to-right cranks.) I still don't understand why a size range of about 7% of total length fits a human population whose legs vary in length by much more than that.

There are some fundamental laws that provide for the increased leverage of longer cranks, and longer-legged riders - whose legs, because they are longer, are less succeptible to the potential injuries associated with the more accute angles at the top of their strokes - should be able to benefit from this. Still, the change in leverage is proportional to the change in crank length...which only varies across a small range (7%-ish). And that, because it doesn't take cadence into account, only governs power in one-half pedal stroke.
 
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