Bicycle Mechanics - How do you cut the steer tube?

What type of saw would I use?

Should I cut the steer tube to be the same height as the stem or a little bit shorter?

Thx!

This is for a threadless setup, right, and has a metal steer tube (not carbon)? First of all, remember that it's better to cut it rather long and use a bunch of spacers, than to cut it at a length that you end up regretting later. Are you positive how high you want your stem?

That said, I install the headset, assemble the fork/headset/frame together, add my spacer stack, then plunk my Park Tool threadless-fork saw guide (http://www.parktool.com/tools/SG_6.shtml) on in place of the stem, put some cutting oil on my hacksaw blade (fine-toothed bimetal blades are good) and cut it. A little deburring with a file, smack the star nut in place with the proper tool... ta-da! :)

There should be a slight gap between the top of the steer tube and the top of the stem, because if there isn't, then the top cap of the headset will bottom out on the end of the steer tube and then it can't take the slack out of the headset bearings. Two to three millimeters would be good.

If you aren't positive you're ready to tackle this task, it might be smart to take it to a trustworthy LBS and have them handle it. The right tools make for an even cut and a well-positioned star nut. Hope that helps :)

If this is a threadless column, you are setting the max height available to you. You can cut with a hacksaw. Make sure the blade is good. See Fork Sizing (http://www.parktool.com/repair_help/howfix_forksize.shtml)

Some people do use a pipe cutter, which can work. In either case, you should finish the cut with a file, removing any sharp edge.

me an my frein julio used a sawzall.

if you're going to use a hacksaw you need to make sure that you have a guide for the steer tube. regardless you'll probably have some burs to file off.

Using a pipe cutter is soooooooooooooooooooooo much easier and gives you a clean square cut!!!!!!!!!! .......provided you're not cutting on the threads, if you're talking threaded steerer tube.

Using a pipe cutter on Aluminum steerer tubes might flair the tube.

i've never heard that before Kevin. Have you experienced this?

Originally posted by Crack'n'fail
i've never heard that before Kevin. Have you experienced this?

I have seen a few come into shops I have worked. People come and say "Hey this is a new fork, I put everything on it measured it, cut it with a pipe cutter, went to put everything back on and it is really hard/impossible to get the spacers/stem/headset parts on." So we pulled out the calipers and measure and sure enough the the end is flaired. If they had left it a little long no problem we would hacksaw the flaired part off. If they had cut it to the smallest length possible they were out of luck.

I have also heard other mechanics I have worked with say the same thing.


Also if you use barends or ODI lock on grips you shouldn't use a pipe cutter to cut bars either.

Thx guys. This is for a threadless fork.

I used a tubing cutter on mine but you have increase the pressure on the cutter in very, very small increments and make a lot of turns. Or as Kevin said you'll flair the tube.