They don't actually stop all that well. The short arms and pivot point of that design allow for a lot of mud clearance but aren't ever going to stop all that well. I think it's primarily an arm length issue. I have some old Diacompes of the same design but longer arms and they work much better.
Make sure the pivot points and cable ends are in the same plane (eg run the brakes kind of wide). Set up the brake pad arms appropriately. Use Kool Stop Salmon pads. Straddle cable height is immaterial (although theoretically lower is better) so don't sweat that too much.
I just set up some Euro X (magnesium) and i'm pleased with them - great feel, good modulation, *lots* of pad clearance and easy to adjust/fine-tune. i agree that stopping power is just adequate . .. but it's certainly enough to scrub speed in a hurry and lock up a wheel if you need to.
first, if you're using carbon rims, get different pads than the carbon specific ones supplied, which i found to be absolutely worthless. not sure about the other stock pads, but i'd second the recommendation for some kool stops as those have always been tops in my experience.
I ended up with the straddle cable carrier about 1.25 inches (approx. 2 fingers) above the tire both front and rear and the length of my straddle cable is set so that the pivots/cable stops are in the same plane as Chris notes. keep the barrel adjuster cable stop threaded almost the whole way so you can make quick adjustments after the cables stretch/pads wear - or set up the adjusters so that you account for differences when/if you swap wheelsets that have different rim widths (you'd probably have to tinker with pad placement too, but sometimes you get lucky!). also, if you are an extreme weight weenie, only one grub screw is needed to keep that straddle cable in place.
pad adjustment is pretty straightforward - just takes a bit of patience and don't fully torque everything until the whole set-up is ready to go - i.e., carrier where you want it, straddle cable at the right length, and the brakes are balanced. - because you'll most likely have to do some fine tuning with pad placement after you're done playing with the other stuff. if you keep it just tight enough, you'll be able to do that fine tuning with your fingers, then you can torque it to spec.
from the TRP site:
In the old days Cyclocross brakes were notorious for their mediocre performance. It was just expected that you'd have no power, too much noise, and terrible performance in most conditions. Fortunately TRP set out to do Cyclocross brakes differently. Our driving mission is always to create the lightest brake possible while retaining (or in this case inventing) optimal performance characteristics. Now that you are rolling the finest CX brakes on the market, here are a few insider secrets to help you optimize your set up:
Thanks for all the help. I am on my way to a dialed in brake setup. I found out that TRP Euro X Alloy differ from the Mag's and Carbon. They have Forged alloy brake carriers. Not the nicer machined ones with readings of toe in/out that the Carbon & Mags come equipped with. Got those on order.