KH crank lengths and Q-factor


I noticed that when you look at them side on my 125mm cranks are the same length as my friends 140mm KH/onza cranks. It seems that the q-factor is included in the crank length.

So, does more Q give you more torque? Will 125mm kh/onza cranks be the same lenght as 110 or 115 strait cranks? Is the q-factor included in the crank lenght in all cranks or just kh/onza?



Thats not right, the 25mm Q factor on KH cranks would make a difference of <3mm on crank length (straight as opposed to angled). Have you tried measuring the actual crank length with a tape measure? It might be that the KH’s are quoted from hub interface hole center to pedal interface hole center, and your friends is quoted as the length of the body, or vice versa.


EDIT: Just measured mine, it seems the KH values are straight line values taken from the axes of the pedal screw and hub interface holes. So a KH/Onza 125mm crank is actually slightly longer than that physically, but the pedal is as far away from the hubs rotational axis as a non-Q’d 125mm crank.

Loosemoose, I’m not very smart and i didn’t understand that.

This is what i meen.

You can see my awsome paint skills. :stuck_out_tongue:

untitled.bmp (696 KB)

I think that’s what loosemoose was talking about.

If the distance is still 125 mm from hub to pedal in a straight line, it won’t affect torque, except to make your wheel more wobbly.

I understand what you’re saying, but the Q-factor doesn’t introduce that much of a length difference! I hope these pictures will help explain what I mean. I think the koxx cranks are measured differently to the KH ones, but I don’t know because I haven’t got a koxx crank lying around that I can measure:

This is probably wrong (from your explanation it seems the koxx cranks are a lot longer than the quoted length, not shorter as this picture shows).

This pic should help explain the difference between actual crank length and distance from the hub perpendicular to it:

With a Q-factor of 1 inch (as stated on the KH website), it only adds 2.5mm of length to the crank (Pythagoras’ Theorem), and is a long way from the 15mm needed to make a 125mm crank 140mm in actual length!


Crank Differences.jpg

Crank Pythag.jpg