Milling a stem is the best solution?
 

I have a bike with a short headtube (Affinity Lopro) and my stem (150mm tall, Nitto Pearl 9) going to the absolute bottom of the headtube is still too far out, like 20mm too far.

I imagined milling the fork but soon learned it was a bad idea because it could compromise the integrity of the fork. Then some local riders suggested that I mill the bottom of the stem but I don't know if it is a good idea.

Is milling the bottom of the stem something that is usually done? Will it compromise the integrity of the stem (removing 20mm from 150mm)? Any other advice (besides getting another stem)?

get another stem - they make all sorts and they are many cheap ones and you won't end up smashing all your teeth out.

I've never done it but I'd imagine if you match the angle pretty close and cut with hacksaw then you'd be in business. I've never measured but I'd guess quill stems have a 45° angle. Grab a mitre box to get that 45° if stems are in fact 45 degrees.

Hmmm, if you've a very long stem might be tough to fit into a mitre box, though....

Un disclosed data... ? this a 1" threaded fork?
yes the butting reduces the ID at the bottom.

I would consider a quill to threadless adapter, they are not very deep insertion
and clamp a threadless stem onto it. you can pick from a much wider array of stems, then .


Someone will buy the nice Nitto stem as it is..

You could cut the stem shorter as mentioned above. Just make sure you scribe a new minimum insertion line so someone down the road doesn't raise it too much. The other option is buying one the correct length and saving the long one for someone that needs more height.

The only problem I can think of with cutting the stem shorter is if the stem tub is not uniform in thickness (i.e., if it has a tapered inside diameter to accommodate the forcing cone used to hold the stem inside the steering tube). If that's the case, don't even think about cutting it down.

this. Do not mill!

^What he said. Do not cut. Look inside after removing wedge and bolt. Base is thicker where wedge pushes against base of stem.
Buy a shorter stem.