[Closed] Steerer Tube Cutting - tips and advice?

Have you got an old stem kicking about? They make for a cheap cutting guide..
And "measure 2 or 3 times, cut once" 😉

If you're not confident, buy a guide and use it with a hacksaw, a new blade preferably.

A half round file is best, means you can tidy up the inside as well.

Depth of SFN is dependant on how long your bolt is, usually 10mm is about there, as long as the bolt goes a thread or so through the bottom of SFN.

Do you have an old stem? Use that as a guide. The cut doesn't have to be perfect.

Buy a star nut fitting tool. They're cheap, quick and get the height right.

Any old half-round file will do.

Remember that the cut is made [b]above [/b] the new stem. I know someone who made a simple mistake.....

I can't recommend [url= http://www.chainreactioncycles.com/x-tools-saw-guide/rp-prod10222 ]one of these[/url] highly enough; at £15 it's a bit of a bargain (you don't need to pay silly money for a Park) and should be in everyone's tool box. They're also great for cutting bars (off or on the bike).

[img] http://media.chainreactioncycles.com/is/image/ChainReactionCycles/template_sample?$detail$&$id=prod10222_Black%20-%20Silver_NE_01&$offerhide=1&$promohide=1&locale=en [/img]

The only time I used a pipe cutter to cut a steerer it mushroomed the end enough to make it difficult to actually slide the stem and spacers on!

Measure many times maybe allow a bit extra for fine-tuning you can always cut it off later. Fine toothed hacksaw goes through the steerer easily. The cut doesn't need to be particularly level the spacer below the top cap takes care of any irregularities.

The top cap bolt has to reach the star nut

I am led to believe that it is easier to cut more off than to stick it back on.
Deep breath and go for it. Hacksaw and old stem, or wrap with tape and go carefully if you have a steady hand.

I use a jubilee clip tightened around the steerer tube & a fine toothed hacksaw.

Do you have an old stem? Use that as a guide

I use a jubilee clip tightened around the steerer tube

Have you got an old stem kicking about? They make for a cheap cutting guide..

Two old stems FTW. Clamp them either side of where you want to cut and you have a good guide that won't slip. If you're cutting carbon you need some spare blades and a dust mask.

What's the minimum you can cut off using that x tools guide? Guessing cutting off an extra mm or two is not easy?

You can cut a bit off , but you can't cut a bit on.

Get proper pissed and go for it

I've done a good few over the years, have tried using a stem as a cutting guide but I get better results just going freestyle and trying to keep a steady hand.

Doesn't matter if it's a little bit on the piss, you should have a decent gap from top of steerer to top of stem anyway.

I used a b&q pipe cutter. Worked a treat. First time I'd done it and it was fine.

Just go for it.. what could possibly go wrong
http://singletrackworld.com/forum/topic/arrrrrrgh-ive-cut-my-steerer-too-short-help-please
😳
Yes that was me

Nightmare! What gap can I get away with? I read the steerer should be 2-3mm lower? Any harm if it's around 4-5mm? If yes I need to reduce it by a mm or 2 to use a smaller spacer!

What kind of file do you need to smooth off the cut?

A pipe deburrer works well, better than a file I've found..

[img] [/img]

It's really not hyper important to get the cut perfectly square, I've never used a guide.

Star nuts on the other hand are pretty much screwed if you don't tap them in straight, so save yourself the agro and use a star nut installer. X-tools one does the job.

It's a steering column not a brain. Just chop the bloody thing off. Use an old spacer as a guide if you must but as nothing should actually touch the very top a tiny wobble is irrelevant.
Or buy guides etc if you are a sucker for gadgets.
Bars the same. Just cut them straight. A wobble does matter here either.

PJay - Member
I can't recommend one of these highly enough; at £15 it's a bit of a bargain (you don't need to pay silly money for a Park) and should be in everyone's tool box. They're also great for cutting bars (off or on the bike).

edit before i got one used a few wraps of tape - doesn't have to be dead square after all

as recently said be wary on the star fangled nut - use a tool or bodge something like a stack of washers on a bolt inside the stem so the star fangled stays at correct angle

I'd recommend a pipe cutter, as i seem incapable of getting a straight cut, i msnaged to saw into the guide when i used one, so still got a wonky cut. The downside is a slight widening of the end which does make it tight getting stuff over the end but not a major hassle and a nice clean cut.

Edit: most people arent as inept with a blade as me, we buy sliced bread

have a practice cut half an inch from the top. Mathematically, you will then be infinitely more your experienced at cutting steerer tubes than when you'd never done it. You could even do 2 practice cuts if you've got the space, and double your experience. Also means you get to find out if your hacksaw blade is slightly off line.

and this:

Buy a star nut fitting tool.

I resisted for a while, but eventually bought one and wish I'd caved earlier. None of this tappy, tappy, squinty, quinty nonsense: spin on the SFN, place, one big whack with a hammer, and you're done. Tappy, tappy, squinty, squinty method is also very hard/impossible if you've not got a square cut.

Just get an axe and give it a good swing, she'll be right.

Seriously, just measure twice, measure again, and cut with a hacksaw. It's not a precision cut, it just needs to be good enough. In an ideal world you should have a spacer above the stem anyway so that everything is fully supported, especially if you have an aluminium steerer and especially if the topmost stem clamp bolt is near the top edge of the stem. File off any burrs with a half-round and you're done.

I've always hated star fangled nuts. Never had a problem bashing them in with a hammer (keep an old bolt for the bashing-in duties, as you may need to whack it sideways in order to fine-tune the alignment once the nut's in), I just object to the idea of a component that goes in like that and can't be removed without an abomination of a process. (And yes, I know they don't generally need to be removed. It just makes me go 'ugh', ok?)

So I've recently started using [url= http://www.wiggle.co.uk/lifeline-compression-plug-with-alloy-cap/ ]these[/url] instead, which have the added bonus of allowing you to build everything up before you cut the steerer (you'll be wanting a pile of spare [url= http://www.wiggle.co.uk/lifeline-silver-alloy-headset-spacer-kit-6-pack/ ]spacers[/url]) so you can actually go and ride to make sure you've got the setup right before you cut.

What gap can I get away with? I read the steerer should be 2-3mm lower? Any harm if it's around 4-5mm? If yes I need to reduce it by a mm or 2 to use a smaller spacer!

You need to be sure that the top of the steerer (when pre-loaded) is above the shaft of the top bolt on the stem.

Nightmare! What gap can I get away with? I read the steerer should be 2-3mm lower? Any harm if it's around 4-5mm? If yes I need to reduce it by a mm or 2 to use a smaller spacer!

The total stack of stem and spacers should extend 2~3mm above the steerer. What's required is for your top cap to avoid contacting the steerer once the headset is preloaded, and top caps are normally bevelled with about 1mm extending below the rim that contacts the outer stack.

The topmost part of that outer stack can either be the stem itself or a spacer, but ideally you want it to be a spacer: it's generally advisable to have a ~5mm spacer between the stem and the headset to reduce the peak stress in that area, and another between the stem and the top cap to prevent deformation of the steerer and maximise the grip of the stem. Though, broadly speaking, steel steerers should be less fussy about this than aluminium or carbon.

When I started mucking about with bike maintenance (I'm still pretty ham fisted) I bought a nice thick book (Zinn) but don't forget that in this day and age You Tube is full of handy videos; the [url= http://www.parktool.com/blog/repair-help?query=&sort=featured+desc%2C+postDate+desc ]Park Tool website[/url] is also a hand resource.

I use a stem with a sacrificial spacer on top. Been fine for alloy, steel and carbon. Measure three times, mark and space to the right height. It needs to be reasonably square on a carbon steerer for the expander to sit neatly, but hand cutting is fine. Star nuts aren't used in carbon steerers.

If you really aren't sure, it's a £10 job at your LBS.

Personally, I'd buy a guide.

You don't have to pay much and once you have it, you have it. I've made a point of buying stuff like cutting guides, star fangled nut installers, headset press etc. The Cyclus, X Tools etc stuff is perfectly good for using at home.

Having spent years bodging stuff, it's nice to be able to do a quick and good job.

Considering that star nut does not sit on top of the alloy steer tube unlike it carbon cousin, do we still cut the alloy steer tube 3mm less that the scribed or measured line? This also assumes that the star nut was driven or pushed deep enough for the stem cap bolt to reach. I am cutting mine the first time. Thanks

...do we still cut the alloy steer tube 3mm less...

I just use tap around the tube and an old spacer. For carbon, a square cut helps because of want the expander plug to fit flush. It's not a big issue.