What’s my correct crank length

[novetan]

I bought my bike quite a few months back but without realizing the crank length is 172.5mm until one day I saw the marking when I overturn the bike for a wash. I’d have thought the standard stock length is 170mm. I wish to get it right. I’m 5’ 5” (1.66m) and inseam is 29.5” (0.75m). I tried several web computation and got different results (varies from 165 to 170mm). Is there a preferred crank length for certain type of rides (such as sprint or endurance) or its strictly governed by ht and inseam. My rides are mostly endurance and with some climbs. Anyway, being not so technically inclined, I wonder whether that minute 2.5mm does make any difference.

 

[CAMPYBOB]

Whatever feels good and works...works. It's all personal preference and what the power meter spits out, if you're into racing.

That said, 170 to 172.5 meets the pro standards (for whatever they're worth) of today. You'll find some guys 5' 6" using 175's.

How have your 172.5's felt? You didn't notice the change until you read the sticker on them...any change from what you had been riding (170's?)? Power change or RPM change?

 

[alienator]

There is no reliable formula or method for determining what crank length is appropriate for you. The best way is to try some different lengths and use what feels best, but alas, that's an expensive method. Do you feel anything is wrong with the 172.5mm cranks you're using right now? If not, don't worry about it.

 

[novetan]

Thks guys for all the replies. This my first road bike and there isn’t anything for me to compare. But the riding seems ok so far. Guess it’s a kind of psycological thing.

I reckon it’s similar to golf club. I recalled yrs ago Freddy Coupled (I think) was testing some golf club and he hit very well in one particularly club. When the grip was removed revealing the length of shaft, it was actually 5mm longer than his usual club length. Then after the hitting was terrible.

 

[ambal]

Save your money, 2.5mm isn't going to make a noticeable difference to most riders.

 

[ambal]

A set of these might do the trick; http://www.powercranks.com/ they're pretty good value at about a thousand dollars a set.