1 inch threadless fork, can I convert my existing fork?
 

I have a beautiful NOS columbus SP fork. It was built for a six foot five guy so it's freaking huge. Can I simply cut the fork to fit my new frame, install star nut and 1 inch threadless headset? If so that'd be awesome. I just want to know if it can be done. The fork is from the 70's. I presume is a 26.4 crown race.

I don't think a threaded fork from the 70's can be used on a modern frame designed with a threadless headset. If the bike was of the older threaded headset design, then I think you could have the fork cut down and re threaded at a smaller height.

why do you presume, cannot you Measure?


Blind Guessing from insuffient information [again]

Is the new to you, frame one previously using a 1" fork?
is the fork so long a steerer , that if you cut off the threaded portion,
there is still sufficient steerer tube to get a good stem clamp around it , above the headset,
at a Height you can tolerate?

Measure everything involved and get back on all that.

when it is cut to length, are there going to be threads left?

The wall thickness is the same in both types of steer tube, so as long as there are no threads left (as asked above) it presumably is okay. Besides double checking the crown race, make sure the forks aren't very different in length.

The fork has over 10.5 inches of steer tube...

A simple question can I cut the tube for it work with threadless headsets? I don't know anybody in my area to thread it for me. I would cut it to fit and then thread it. But I figure I might as well go threadless.

I would be hesitant to do any rethreading unless the person doing it really knows what they're doing. The fork threading dies that most shops have do a poor job cutting fresh ones. Often the metal tears off the steerer's surface. The best method is to single point on a big lathe. I see no reason why the fork couldn't be cut down (clear of the threads) and used with a threadless upper head set stack and stem. Andy.

I forgot to add this. The op's information was lacking, even after the second posting with the steerer's length (10.5"). Without the head tube length, head set used, spacers needed and stem clamp dimension we still don't know how long the steerer will need to be. Andy.

If there is enough unthreaded steerer tube left after removing the threaded portion, I don't see any reason why the OP can't use the fork with a threadless 1" headset and stem. Note I said if.

My thoughts as well.