About those Magura's, how well do they work in the cold? And how reliable are they? What kind of clearance do they have? And do they really provide more stopping power even with css rims?
And what sort of pads should be used with them? Magura brand? I see they have some for ceramic rims, I guess that applies to carbide rims too?
The Magure rim brakes are hydraulic; they work as well as disc brakc hydraulics in the cold. I've only ridden in really low temperatures a few times, in sub-zero probably only a handful of times, and never noticed any degradation in performance. Nor have I heard of any problems.
Magure hydraulic rim brakes are the most reliable brakes there are. They come as a closed, fully assembled, no bleed system and require no service, ever. They are truly fit and forget. Mine have done about 6500km on the same set of blocks, hardly worn. I wasted the money I spent laying in three sets of spare blocks, besides the spare set the builders of my bike included in the welcome pack, when I bought the bike five years ago. (I ride out in the country mostly. I don't brake all the time, but when I do brake at junctions, I usually brake hard.) I've adjusted the blocks once, when I fitted a rim of a different width; I've never adjusted them for wear; they're essentially self-adjusting.
You run Magura brake blocks at the same 2mm or so spacing as any other rim block.
It may be possible that Maguras could provide more grip on CSS rims than mechanical systems. but I think, just on general principles, that it would be marginal. It's the CSS rims that are the problem, not the gripping power in any kind of good bicycle brake available today. The point of the Maguras is that they work under all conditions, and they work the same every time, very consistently, and they are very progressive, which you can't say for disc brakes.
There are several kinds of colour coded Magura blocks available, and aftermarket blocks as well, that some swear by for greater stopping power at the cost of longevity. A few years ago I followed a thread on a technical conference and the experience there was that the common black block gave the most stopping power with the CSS rims though it wore faster than the grey or the green or whatever the special CSS block was. It was still a longlived block though, by any standards.
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If you really want a brake that works under all conditions and keeps working without any clearance worries in icy and snowy conditions, you should consider Shimano's roller brake at the front; there is unfortunately not a version for the Rohloff. You'd have the same problem, that Thorn won't put disc tabs on a steel fork, and the roller brake has a torque arm that bolts to disc tabs. But on the other hand, it is a fully enclosed brake, it is extremely powerful, its service consists of squeezing in special grease from a clean-handling tube at long intervals through a small port. I've had the limp IM-40 series, long obsolete, and on a bike for the Euro-elite
http://coolmainpress.com/BICYCLINGsmover.html I had the very powerful IM75 series roller brakes (check out those cooling fins -- it needs them!), which killed the Magura Louise discs I had on another similar bike at the same time -- and the Magura Louise were then as now said by their fans, of whom I was one too, to be the best disc brakes (a lot of) money could buy. My not so humble opinion: The best modern roller brakes are an overlooked sporting proposition, unfairly relegated to city bike use.
On the downside, the IM75, and possibly all powerful roller brakes, are damned sudden if you ride them on the edge; if you don't want a face-plant, you better pay attention to how you handle that lever; they're like discs set up with miniscule tolerances and the booster turned up. I found the Magura rim hydraulics, of which my bike maker especially chose the weakest one (largest chamber, lowest pressure) to suit my careless riding style, a relief after the demands of the IM75 rollers.
Andre Jute
