Road Cycling - Crank Length Sizing

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fore0121
02-05-04, 01:03 PM
Could someone please tell me something about Crank Lengths. I'm wondering:

1. What is the 'Standard' crank length (172.5 or 175)
2. How do you calculate the correct lentgh for you (5'9", 32" inseam)
3. How do they measure it? (centre of crank to end of arm or to centre of pedal axle?) I'd like to know what I'm riding now.

As usual, any and all input is appreciated.

f

Brillig
02-05-04, 02:42 PM
http://www.sheldonbrown.com/cranks.html
sch
02-05-04, 02:53 PM
Road standard is 170mm, ATB generally 175mm,
track bike 165mm. Expensive/large framed road
bikes sometimes have optional 175 or 180mm
cranks. Shorter cranks are easier to spin. A 5mm
difference is noticeable. There is no algorithm for
crank length versus body/leg length. Measure is center to center, (axle to axle). Steve

Laggard
02-05-04, 03:45 PM
http://www.velonews.com/tech/report/articles/5257.0.html

Mine are 172.5.

Indurain reportedly used 190s during his hour attempt.
khuon
02-05-04, 03:48 PM
Could someone please tell me something about Crank Lengths. I'm wondering:

3. How do they measure it? (centre of crank to end of arm or to centre of pedal axle?) I'd like to know what I'm riding now.

You can usually find the size stamped on the inside-facing portion of the crankarms.
Avalanche325
02-05-04, 04:46 PM
Make sure that the inseam measurement that you are using is your crotch to the floor in bare feet. Not the inseam of your Levis.
Feltup
02-05-04, 07:33 PM
You will be good with a 170.
BlastRadius
02-05-04, 08:41 PM
Kinda of off-topic but I'm 5'5" with a 75cm inseam and the calculations recommend a 160mm length crank.
Question is, has anyone around my height actually tried 160mm or even 165mm cranks and noticed a difference in spinning or power?
Henry
Bruco
02-06-04, 03:05 AM
[url]Indurain reportedly used 190s during his hour attempt.

:eek: Big Mig sure knew how to grind...
MichaelW
02-06-04, 03:16 AM
The standard crank length is like the standard shoe size. For any size leg there is normal, long and short, but my short may be your long.
There is a good guide to fitting at Peter White cycles.
For average male riders, around 5'10" tall, 170 is generally used as normal size, with 175 for longer applications such as MTB, and 165 used for track riding.