Shortening a steel steerer-tube: Why not use a pipe-cutter?
 

I've used a pipe-cutter tool for shortening a steel seatpost. It makes a perfect cut, with minimal effort, and relatively quickly. Why then does every instruction I've read call for using a hacksaw-and-guide when shortening a fork steerer tube? I had my LBS shorten the steerer tube on a new steel fork and they too used the saw-and-guide. It seems to be unanimous. Why is that, when an inexpensive pipe-cutter tool is so much quicker, easier and gives a consistently perfect result?

While we wait for someone who knows the answer, I'll speculate a bit. :)

1. A steel steerer is probably harder than copper pipe, so if you're cutting a bunch of steerers (like a shop or production facility) you're running up tool costs.

2. Ever start to cut a pipe and don't have it lined up quite right? How would you like to do that spiral cut thing with a fork?

I'd go for #1 of what @pdlamb said. Along with the fact that many people probably don't have a pipe cutter and if they do, then it won't cut something the size of a steerer tube. However I have one that will cut over 4" diameter pipe along with 3 or 4 pipe cutters in various smaller sizes.

There's also the mushrooming effect, which anybody who's cut a handlebar then tried to slide the grips on will be familiar with: a pipe cutter tends to push the metal away on both sides of the cut, making the diameter a smidge larger. I solve this with a file after cutting a bar, I don't know how much work that would be on a steerer.

They are technically called roll cutters, or specifically "displacement cutters" and for a reason. When they "cut", the wheel just "smooshes" the material out of the way until it breaks in two leaving a flaired mushroom end on the outside and a huge burr on the inside. Much filing/reaming inside and out required for a close tolerance stem insertion. Really is meant for actual gas pipe, not chromo or high end light weight high strength steel.
I see I was typing way too slow, Joe.:o

+1. Steel steerers require a good file or lots of work and patience with some sandpaper or dremel etc. to take off the flair but can be done Aluminum is a bit easier. Also take your time with the tube cutter doing more gradual tightening for each rotation than you would with softer metal tubes. Had to do this on my current bike. At least it makes a clean, square cut easier than most methods.

If you have a pipe cutter big enough, there is no reason you can’t use it, as long as you file the edges (as someone else mentioned, you get some mushrooming). Its not a big deal to clean up the edges. I doubt I have ever spent more than a minute or two doing it.

Before I got a saw guide, I liked using a pipe cutter because it gave me a straighter cut.

My first rule of good mechanical work is to use the simplest tool for the job.

For cutting bars, stems and seatposts, that would be a hacksaw.

A simple guide can be made with one or two hose clamps.

The case against pipe cutters is simple,it's the wrong tool for the job.

1 in the size range needed it's costlier than a saw.

2 pipe cutters are for soft materials that flow easily. Heat treated steels and aluminum alloys aren't.

3 pipe cutters roll a large burr to the inside, and raise a smaller one on the OD, so there's more clean up work needed.

4 with a modicum of skill, a saw raises a small burr which files off easily.

FWIW pro bike mechanics used hacksaws for a century, but as culture evolved, folks started doing more DIY, and eventually word got out that it was easier to buy a pipe cutter than to learn to cut straight with a saw.

I assume the reason someone would consider using a pipe cutter is because they already had one. If you already have one, it is cheaper than two hose clamps.

The important thing is to pick the method that works best for you, and then be a d!ck about it.

The bigger question is will you have enough threads left when you are done cutting, how ever you do it?

Surely it's a threadless steerer tube.

Or a few seconds with a bench grinder to chamfer the end.

I guess I am way to C&V :50: :beer:

plumbers have been cutting galvanized and black gas steel pipe with pipe cutters forever. mechanics steel brake, fuel, and cooler lines as well.

How many uncut steel threadless steerers can there be? Almost all of them are on cheap complete bikes. And people who buy surly frames never cut the steerer

I'm having a hard time fully interpreting your post, please elaborate.

What?? There are plenty of bike made with threadless steel steerers. I just finished making a bike with one. Left it long to double check the fit set up before I consider cutting it a second time to a final length. I used a hack saw and a bit of masking tape as a visual guide to keep it close to square before I used both a belt sander and a rat tail file to finish it off with. Andy

I have a saw and a park guide and a pipe cutter big enough for steer tubes, I generally use the pipe cutter and a file to cut steerers.

I've cut a couple of steel steerers with a pipecutter.

Lived to tell about it :)

I love how quickly this thread sailed off a cliff. I'm usually in the Folding Bikes section and this one is new to me..so far it's pretty funny!

It takes less than a minute to cut a steel steerer with a $1 hack saw blade. What's to debate?

The only cutting guide you need is the stem you already own and aluminum spacer.

And this thread is pretty mild.

But I'd imagine black steel pipe pipe for plumbing is a lower grade steel that cuts easier than the better grade steel in a steerer tube. And better grade steel probably shortens the life of the cutting wheel, though they are inexpensive and easy to replace on most.

I have cut some better steel tube that was thinner than plumbing iron pipe with a pipe cutter, they didn't mushroom out externally. However they did roll in a pronounced inverted flare toward the inside of the tube that would have been a real pain to remove evenly if I had to put something inside them like a expander plug.

Good catch for the member that ask about threads. I doubt one could easily make a pipe cutter work on a threaded steerer tube.

My strong impression is that most people who stick together steel frames for a living or hobby are doing threaded headsets for aesthetic reasons, or using carbon or MTB forks.

Factory forks come uncut but steel ones are now vastly outnumbered.

So I figure while one guy might do it a lot, most aren't much.

And finally the Surly LHT and Cross Check were long well known for having very long top tubes (10mm longer than the seat tube) that resulted in a stack of spacers topped with a riser stem.

We sell a lot of modern, mass produced bikes at my shop (with Surlys being a mainstay in that category) that have steel forks, and almost all of them have threadless steerer tubes and we cut the steerer tubes on almost all of them. One of the main purposes of threadless steerers is that the manufacturer can produce one steerer tube length for all frame sizes of a certain model bike. So on all but the largest frame sizes, the steerer will need to be cut accordingly, unless a customer has a specific request.