172.5mm vs 175mm MTB cranks

Tomas91

Hi!

I got a little problem here - accidentally bought a 172.5mm MTB cranks instead of 175, do you think I will notice any difference?
Riding MTB marathons, rather strength oriented rider.
I´m 172cm (5´8 1/2") tall, my inseam length is 32"

I know that the length difference is minimal, but I´m little bit concerned since I completed a 130 miles MTB race on my previous setup (175mm crank length) with no pain but legs pain, so I feel like I shouldn´t change anything.

What do you think, should I give them a go, or get 175, that I´m used to?

cooldad

Doubt you'll notice.

Giraffoto

Tomas91 wrote:

. . .accidentally bought a 172.5mm MTB cranks instead of 175 . . .

Who did you accidentally buy them from, and do they have a good returns policy? Swap them if you can, because you'll always be wondering otherwise. Although it won't make that much difference.

If you can't, try holding the tips of your thumb and index finger 2.5mm apart, look closely at the resulting small gap, and ask yourself how much difference it will really make . . .

thelonegroover

If you are a strong rider, as indicated in your original post. I doubt you'll notice 1/8", may even help. Having less leg movement.

njee20

Road cranks are traditionally 172.5mm as 'the norm', I certainly don't notice when I swap, there's plenty of people who think shorter is a better idea.

bernie1973

According to my calculations - which may be wrong as they are based upon 1990 maths exams - the effect of the reduced crank distance on climbing effort would be about the same as turning a 24x35.5 gear instead of 24x36 gear. Obviously I realise that you cannot turn a half toothed gear (even with a SRAM XX1 drivetrain) but I think the point is that the difference is minimal. Will wait for the first physics professor to challenge my maths!

thelonegroover

Should also give slightly better pedal/ground clearence.

Tomas91

Giraffoto wrote:

Tomas91 wrote:

. . .accidentally bought a 172.5mm MTB cranks instead of 175 . . .

Who did you accidentally buy them from, and do they have a good returns policy? Swap them if you can, because you'll always be wondering otherwise. Although it won't make that much difference.

If you can't, try holding the tips of your thumb and index finger 2.5mm apart, look closely at the resulting small gap, and ask yourself how much difference it will really make . . .

That´s the problem - they are second hand cranks bought from a guy who doesn´t accept returns. If he did, they would have already been returned.

But anyway, it looks like I don´t have many options. Should give them a try and if it was too bad all I can do is sell them further on E-Bay...

supersonic

You won't notice.

The Rookie

I really doubt you will notice at all.....