I wrote about cutting carbon steerers a little while back, and up 'til this point I've held the view that I ought to write to a fairly low common denominator as regards the issue of tools and their probable use among Slowtwitch readers. Then I thought, "Why not let the readers know about some of the tools available."

I've turned over a new leaf. We don't write down to readers anywhere else on Slowtwitch, why do it when it comes to bike maintenance?

Let's get right into that with a discussion of steer tube cutting. What does a pro mechanic do when he has all the tools he needs, and he wants to mitre a steerer, regardless of material? He uses a special -- made for bikes only -- mitre block.

The one above left is for threadless steerers. It is made by Park Tool, as are a lot of my tools, the design of which is especially elegant. I've had a couple of different mitre blocks, but this one rocks on the others. Because if its unique ovalish shape it takes either 1" or 1 1/8" steerers without having to stick in an insert to reduce the inside diameter of the block for 1" steerers.

It's part of a set which will allow you to mitre a threaded or threadless steerer. What's the difference between the two steerer types? A threaded steerer (like the one below) is the old-style, which uses the sort of stem that is shaped like a "7" (or, in the mountain bike tradition, it might have a right angle, or even an angle where the extension points upward). This kind of stem is called a "quill" stem, and the quill is the thing that goes down inside the fork's steer column.

The newer technology is threadless, and almost any new bike you buy today will have this sort of stem. With this technology the stem clamps onto the steer column.

With a threadless steerer you just put the fork's steer column into the hole, clamp it down, lay the sawblade in the guide, and voila, you're cross-cutting the steerer perfectly square. You've got to make sure you measure the steerer length correctly, of course, and that is covered elsewhere. Also, remember that you can't cut a carbon steerer with a standard toothed hacksaw blade.

If you're going to mitre a carbon steerer with this sort of mitre block, make sure you're careful not to clamp down on the steerer too hard.

The threaded mitre block is much simpler. You don't have a clamp mechanism, because the steerer is held in pace by virtue of its threads. The block is made by bolting a pair of 3/16" plates back to back, with a small space inbetween them (just large enough for your hacksaw blade to fit). Both of these plates have a 1" (or 1 1'8", whatever) hole through them, and the hole in one of the plates is threaded. Two such mitering blocks of different steerer sizes are pictured above left.

You just thread the steerer into the mitre block until you get to where you want to saw. My set has three different mitre blocks for threaded, depending on the size of steerer. Will I ever use them all? Heck no. Then why do I have them? So that I can have obscure tools that others don't have.