Again

I have run "search" for "cut steerer", but found nothing. I am sure there is some discussion of it somewhere in here, but I never find much with "search".
So, what do YOU use to get a clean, square cut?

Stealthammer

Abrasive wheel chop saw.

.....or an angle grinder in a pinch.

HillRider

Fine tooth hacksaw (32tpi or more), a cutting guide and very light pressure. I happen to have a steerer cutting guide (Performance's "Spin Doctor" version) but a stainless steel hose clamp tightened around the steerer with one edge right on the cut line can be an effective saw guide too. Put a layer of masking tape spanning the cut to prevent any splintering and, again, very light saw pressure.

DO NOT use a pipe or tubing cutter.

cbchess

a dremel with cut off wheel will work too. go slow . Don't breath the carbon fiber dust.

FBinNY 

+1, a plain, boring, old tech hacksaw is the correct tool for this job. use a fresh fine tooth blade, and long (full blade) strokes at moderate pressure for a fast clean cut. When finished clean up the cut with sandpaper on a block. I then seal the cut with clear nail polish.

BTW- a perfectly square cut isn't necessary. The tube ends in space, and a gap is needed under the top cap. It doesn't matter if the gap is perfectly square.

sloar 

Hacksaw here, worked great maybe cause I used my $40 park saw and not my $10 hardware saw with the same blade. Gift from my wife, she try's

gizzsdad

I did some research and found that a bi-metal hacksaw blade was recommended. Found these at Lowes:

https://tinyurl.com/6u86qcz

Was able later to use cutting a titanium seat post as well.

FBinNY 

A bi-metal balde doesn't improve the cut, it just makes the saw stay sharp longer. Most decent blades these days are bi-metal -- hard (brittle) steel where the teeth are, hi-tensile spring steel for the rest of the blade. It isn't a new idea, the Japanese have been using the principle to make Samurai swords for decades. Bi-metal construction allows them to retain that "5-body" razor edge yet be tough enough not to snap when struck.

BCRider

Because of the dust and smell involved using a Dremel would be my absolute last ditch option. It's simply one of the jobs where a Dremel is the least desireable method going. Despite what the ads say a small high speed rotary tool is a specialty tool and not a general purpose "does everything" tool like they'd have us believe.

FB', you're right that the cut doesn't NEED to be totally square. But let's face facts...... anyone OCD enough to get a fork with a carbon steerer is OCD enough to want the cut to be straight across to within less than half a degree.....

While I've avoided any carbon bikes I do use some carbon tubing and rod products in my model airplanes from time to time. The best way to deal with it is again a fine tooth saw blade. So far I've made do with using Zona razor saws. Bu I've found that the carbon is quite abrasive to the steel so next time and in the future I'll stick with a cheap fine tooth hacksaw rather than ruin a nice razor trimming saw which SHOULD last for many years of balsa, spruce and thin plywoods.

IthaDan 

24 or more tpi hacksaw and a hose clamp (or a wrap of masking tape) to keep square. Clamp the fork lightly in a sacrificial fluffy bath towel if needed.

noglider 

In addition to the other advice, I recommend screwing a nut on, below the point where you will cut. After cutting, removing the nut will help clean the threads up.

fietsbob

you could make a square miter box of wood, best with a v in the base,
thus have the saw blade at 90 degrees..
and rotate the steerer tube, as you cut, and the cut will be more lathe like.

of course having a lathe, you just chuck up the steerer
and hold the hacksaw and the work rotates under it

Are you REALLY sure the height is precisely what you need?

bobotech

Why should one not use a pipe or tubing cutter? I'm assuming since that they are designed for soft materials unlike CF. What could happen if you try to use a pipe cutter?

I'm just wondering out loud.

fietsbob

Tubing cutters just shove soft metals out of the way pushing a harder wheel
continuing to be forced into the metal..
they actually do not cut out metal. ..

crushing your composite steerer is not a good thing..

Again

Thanks, guys, I appreciate your input!
Went to Lowe's for a 32tpi hacksaw and hose clamp and did the cleanest steerer cut ever!
And it seems to be reflected in the tightest headset installation to date! Apparently the damage done in the past by using a tube cutter made tight installation difficult.
Thanks again, this makes building much more fun!

FBinNY 

Tom, go brew yourself a cup,of coffee.

The OP asked about carbon steerers, which don't exist in threaded versions.

cheers

IthaDan 

I had this as well, and I too thoug it was the cut, turns out I had the expansion nut tight and that expanded the steered just enough that the headset had trouble sliding over. Keep the nut loose until you have it all assembled and it's time to preload the bearings.

IthaDan 

Point pressure= point stress = cf cracks = bad bad news.

Camilo

Just to pipe in after the discussion is over 8-)

Yes, a nice new and/or sharp high TPI hacksaw blade is all you need.

perfectly square is indeed not needed. If it just is too off square, you can pretty easily use a good stout flat file and touch it up, holding the end of the steer tupe against a carpenter's square and up to a light to identify the parts that need to be squared up. You can really get it right on w/ just a few minutes of easy, careful filing. But it's not essential to be perfect.

A miter box type jig really doesn't work well with a hack saw. The simple box-type are really meant to work with a back saw which is a very stiff saw with a very stiff spine. A hacksaw blade is too floppy to really be held square by the miter box, in my experience. The other, more "professional" type of rigs really are made to hold the saw's stiff spine, and the ones I tried really didn't work well with the spine on a hacksaw.

Maybe it could be made to work, or get one that's specifically made for a hacksaw blade, or get a back saw with really fine hacksaw-like teeth, but using the ones I have in my shop, my cuts were no better than if I'd just scribed a square line around the steer tube and then just cut carefully by hand (which is what I did and then touched up w/ a flat file).

The usual addages apply: measure twice cut once, do a practice cut before the final cut, etc. It's really not a difficult thing to do, but the consequences of an error are expensive!

Dan Burkhart 

Ha! I was just going to ask him where he finds threaded carbon steer tubes.

Kimmo

Lolwut? There's such a thing as a threaded carbon steerer?

jolly_ross

So the best way to cut a threaded carbon steerer is to use a samurai sword?

dbg

But it is a good idea for threaded cuts and is now firmly in my future plans.