Wrong Crank Length Set

So, I forgot to set the crank length correctly for my assioma duo power pedals when taking a ramp test. The pedals were set to 172.5mm cranks, but I was riding 175mm cranks.

What effect will this have had on my power - inflated? deflated? insignificant?

Thanks brains trust!

Kinda related:

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Thanks @mcneese.chad. I saw that one, but couldn’t quite work out which direction it would skew in my particular case. Do you know the maths to help me work it out?

Is it: (172.5/175)xFTP? Ie, power meter reading low
(172.5/175)/FTP? Ie, power meter reading high


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Your actual power was a bit higher than reported, but pretty close to insignificant.


Yeah I think it comes to +1.5% higher than recorded. I made the opposite mistake earlier this year after getting a new bike and not realizing it had 172.5 crank arms vs 175 on my other bike.


Thanks for the responses all. Makes sense that actual power would be higher than reported power, given the distance covered is greater than the pedals are calculating it to be. FTP result was 337, so (assuming no error anywhere ever hah) actually FTP would be 337/(172.5/175) = 342?

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