Crank Size

According to Peter White your crank length should be 18.5% of the length of your leg measuring from the top of your femur to the floor.

 

It is usually stamped on the inside of one of the crank arms.

 

Look on the inside of the crank arms. It should be stamped such as 170, 175, etc.

 

^^ No, that will not work at all...

 

Whoops didnt even read your response before i posted. Hopefully that will actually work

 

Have you looked on the inside of your crank arm? It's usually stamped on there

 

Apparently, I may have misread the op's post. Anyway, if the length is not stamped into the crankarm, simply grab a ruler and measure it. Crankarm length is measured in millimeters from the center of the pedal shaft to the center of the bb spindle. If your ruler doesn't have metric graduations, the conversion factor for inches to mm's is 25.4.

 

the OP did not say he wanted to know where it is located, but how to determine what it should be?

 

That's what I thought at first, but after reading the post a second time, I'm not sure because of the wording. Either way, I think all the bases have been covered.

 

@hophead

Thanks a lot for the picture, I've just found this thread through search and I found the answer thanks to you.

 

Glad it helped!

-Scott