Unlike me, my brakes had it.
A question I hear a lot, is what kind of cantilever brakes are good for a cross bike. People want strong, cheap, and effective. I've got news for you - that combination is pretty rare.
Mini-cantilevers, the little thumb-like brakes, are alright if you don't ask to much of them. The bottom line with them is that they are not strong, and no matter how much you gussy them up - I'm lookin' at you, Avid Shorty - you can't make them strong. The geometry is just wrong and doesn't provide enough leverage.
So you need to look at true cantilevers and figure out how to set them up. The alloy TRP (Tektro Racing Products, BTW) Euro-X comes closest to fitting the bill, with a pair coming in around $75 if you shop carefully. But what if that is still too much?
Your choices are between the low end Kore Cantilever Brake, and the Tektro CR 720. I was looking at some Kores a while back and, as a hirsute bike shop owning friend of mine put it, one of his canti-smart employees tried the brakes on his bike, "rode into the parking lot, walked back into the shop, and took them off. Not good."
I decided to try the CR 720's as an upgrade to the Kona Major One. I've had an old set of Tektro Oryx mini-cantis on it, but needed more stopping power for racing. The 720's worked out to around $34 for the pair, through a team shop deal.
Tektro CR 720
Installation was really simple. The brakes mounted easily, and the included cable straddle carrier had two cable stop nuts to help center the brakes. Centering was also made easy by a spring tension adjustment nut at the bottom of each brake; tighten a screw to up spring pressure, and the brake pad moved farther from the rim. For it's part, the straddle carrier came free with the brakeset, and it was identical to the one that Cyclocross World charges $10 for and the same as the one that comes with the alloy EuroX.
Straddle - Tektro, TRP, Cyclocross World: Same/Same
Getting the brakes dialed in was simple. The pads have fittings comparable to Avid's excellent cup & cone washers, allowing the post style brake pads to be toed in properly when the pad retaining screw is tightened into place. The spring tension adjust works in concert with the cable straddle carrier to center the brakes, and you're off.
Those familiar with Canti Fu will wonder what adjustments are available. One of the ancient Chinese secrets is that cantis are very adjustable, and you can make them very bad or very good with some tweaks. Unfortunately you give up a little of that with the 720's, though some of that is offset by ease of installation and a basically good setup. They are not as adjustable as, for instance, TRP EuroX brakes or Pauls, because cantilever can only be installed at roughly 90 degrees to the rim. Angles more than a pinch below 90 degrees are simply not possible, so the super powerful, 10-15 degrees below 90 installation isn't an option. This isn't that much of a setback as it sounds like, however, because 90 degrees offers good power and a short lever throw, and the straddle carrier can be adjusted up and down to change stopping power (and grass/mud clearance). Moreover, because the pads can be toed in really well, you get better pad/rim contact than with a lot of brakes so raw power doesn't matter so much.
So how do they work? Really well, particularly in light of the price. I haven't braked hard enough to really test the 720's effectiveness at the edge, and that a good panic stop will help me figure out just how strong this brake is. It's plenty strong for right now and has led to quick stops in practice and at the one race I've done this year. They are a little weaker than TRP EuroX brakes, and I suspect that Avid's Ultimate Canti dusts them too, at least when it is down in the horizontal position.
But mega stopping power really isn't that important in cross. You need good brakes, but they don't have to be great. These things are way stronger than mini cantis, including more expensive minis, and just a touch weaker than full cantis costing from twice to 20 times the price. Aftermarket Kool Stop or Dura Ace pads would put their stopping power in the same league as the EuroX.
The bottom line is that if you need an inexpensive but reasonably effective canti for your B bike, or if you roll econo and are scraping to put together a high functioning cross bike, you should consider the Tektro CR 720. It will get the job done, and leave you with an extra $40 in your pocket (or more) to upgrade your cowbell and your post race recovery beverages.