How To Size and Cut a Threadless Bicycle Fork

[Raboa]

 

[AndyBike]

Whatever i come up with for the maximum steerer length, i like to leave about an inch extra above the stem.
It might be the case that later on i want to fit the fork to another frame, and the frame is bigger or the headtube longer.
You're never going to notice it, and it gives you more options.

Once it's cut it's cut.

 

[saneagle]

Some good points in it, but he's working for Park Tools. Most of us don't have them, and as long as you have basic DIY skills of measuring and cutting, you don't need them. The length isn't critical, so if you hack-saw it a bit crooked, you can file it level using spacers as a guide. I've done several, and all I used was a hacksaw and file, laying it on a bench or whatever while I cut (no vice). The cut was never straight enough, but no problem to adjust it with a file.

As he said, you can't leave too much sticking out the top because you could get impaled on it in an accedent, but bear in mind that once you've cut it off, you can't put it back on, so it might be an idea to leave it a couple of inches high for a bit to see how you get on at whatever height you've decided. After a few hundred miles and you're happy, you can always cut a bit more off later, but if you're getting old and starting to get a stiff neck and shoulders, you might want to use those extra couple of inches either immediately or a couple of years later. Think ahead!

I disagree with him about too much length under the stem. It makes no difference. Look at some folding bikes with 2 foot stems, or a bike with high-rise bars, and what about all of us that use stem-risers. Having high bars and a low stem gives the same force on the steering head bearings as straight bars and a high stem.

 

[Kev_w]

There's spacers with 1 1/8 holes in them from the auction site, I've a lathe so make my own and always cut the tube too long, as has been said it's easy enough to clean the cut up with the file.

Your saw should have the teeth facing forwards so you cut as your arm extends, not on the back stroke.

 

[AndyBike]

Your saw should have the teeth facing forwards so you cut as your arm extends, not on the back stroke.

Im a sucker for modern technology, so i use a powered cut off saw.

 

[Kev_w]

Im a sucker for modern technology, so i use a powered cut off saw.

Nice! I'd love a small donkey saw but am short of room, I could set the forks on my milling machine table to square them off but it's not a big machine so more trouble than needs be.

I do have a decent small bandsaw but it's made from cast ali and has an ali table so have kept metalwork away from it.