Road Cycling - 2.5mm Crank Length Differ Help

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JCX
08-19-04, 09:25 AM
I'm buying a 54cm bike online. I'd like to have 172.5mm cranks (based on online fit sites, this would be my 1st road bike), but the bike is spec'd with 170mm cranks and there is no changing that (I already tried). all other parts are fine as spec'd.
A lot would recommend buying 1st bike at shop for fit, but I'd get twice the bike if I buy online for the same price.
I'm looking at a ruler and 2.5mm (or even 5mm) difference is nothing. How much would I be able to tell the difference when riding?

sorebutt
08-19-04, 09:57 AM
if you put a shorter crank on a bike you have ridden for years I would say you may feel a difference. But as this is a new bike, and you would need to get use to it, you should not have any problems with a 2.5mm (less then the height of 2 dimes stack together).. you have many other things to get use to, such as geometry, seat position, gearing, stem/handle bar.. etc. etc. etc... this crank will be a part of the character of you new bike.. :)
Retro Grouch
08-19-04, 10:08 AM
I can't tell any difference. My tandem has 172.5mm cranks. My road bike has 175mm cranks. I don't notice any difference. YMMV.

Gonzo Bob
08-19-04, 11:48 AM
There's very little difference. I ride road bikes with 170mm, 172.5mm, and 175mm cranks. For me, the difference is most noticable in the first few miles of riding the 170's after having not ridden them for a while (a week or more). Otherwise I don't notice it at all.