Bicycle Mechanics - JIS Quill stem in 1inch ISO threaded headset

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lemniaalsa
05-11-10, 09:02 PM
Hello all,

I was wondering if a 7/8 inch JIS quill stem would fit in a 1 inch threaded ISO headset. I'm not sure what the size of my fork is, but I can find out if it is necessary.

Thanks!

AEO
05-11-10, 09:06 PM
yes, it'll fit.

I'm quite sure the only place where JIS and ISO is different in the headset area is the fork crown race diameter.

http://www.sheldonbrown.com/gloss_ha-i.html#headset
lemniaalsa
05-11-10, 09:08 PM
and that only matters with the steerer size correct?

AEO
05-11-10, 09:32 PM
nope, same steerer size, just different fork crown race diameters.
Dan Burkhart
05-11-10, 09:48 PM
The headtube ID is ever so slightly different as well. ISO is 30.2mm, JIS 30.0. Close enough that they can be made to interchange. You can also buy headsets that fit ISO frame to JIS fork and vice versa.