They were extremely quiet and their muted usage was a major highlight, as I really enjoyed not having a set of brakes squealing while I was riding down a trail. I didn’t hear the usual wispy chatter that the Storm SL rotor cutouts can make on some of the other Magura brakes, which was a welcome change; it was there, but was very subdued, and you really had to listen for it. Sometimes if they were wet and cold, had dirty pads or rotors, they might make some noise, but after a few good stabs with the lever, they were silent again. Even when getting them extremely hot on long steep downhill’s, they were fade free and resisted heat buildup, and made no scraping or overheating noises, and their performance and lack of noise were outstanding. “Silent but deadly!” A lot of the quietness is due to a couple of features and design aspects of the caliper system, that all work in synergy to keep them silent. The Duroplastic pistons, which absorb less heat than metal, have a special coating, which prevents them from sticking in the cylinder, and reduces friction and stichion. The caliper itself, runs significantly cooler by the combination of using organic pads, the composite pistons and the double arch, which acted as cooling fins.
I never felt any pad rubbing nor drag from the caliper and rotors, and they always flowed freely, regardless of how heavily they were being used. Due to the offset pistons giving toe-in as the lever is applied, the pads realign themselves with the rotor, so their spacing seems to remain proper, regardless of pad and rotor wear, rotor warping and heating, etc. When it comes time to replace or clean the pads, the top-loading pads are simple to remove, and don’t require a wheel removal. Simply remove the retaining screw, grab the tabs on the pads and pull them out, insert a new pair, letting the magnets on the caliper’s piston hold them in place, and then replace the screw. After pad replacement, they aligned in just fine, and if they were installed a bit cockeyed, a good jab from the lever set them in properly.
It’s nice that all the bolts (except for the bleed port) use a T25 Torx head, so only one tool was required for the brakes and rotors. I didn’t have any issue with stripping the alloy Torx heads, especially the large caliper ones, but you do need to be cautious, especially on the clamp, and a light hand tightening and finishing off with the torque wrench is the best approach. I never experienced any slippage in the lever clamp, but I could see where they might happen on some bars, though clamping with the proper torque seemed to alleviate any problems for me. The entire clamp system is an oddity, and perhaps not the most robust or carefully thought out, in my opinion. It uses a double-ended bolt or hanger bolt (machine threads on one end and wood threads on the other), in which one end attaches into the reservoir body (wood threads), and the other end (machine threads) accepts a Torx headed aluminum barrel nut or sex bolt, which is what actually snug’s the clamp down. The alloy barrel nut is fragile, and you need to use caution when tightening it down, else the head can get stripped or sheared off, although I never experienced that problem.
- Front (cut 32″ ) – 178.6 grams
- Rear (cut 57″) – 191.1 grams
- Bolts (alloy) – 2 @ 3.9 grams
- Storm SL 203mm – 147.6 grams
- Storm SL 180mm – 114.2 grams
- Storm SL 160mm – 92 grams
- QM7 (6″ PM 203 adapter) – 22.9 grams
- QM6 (6″ PM 180 adapter) – 23.4 grams
- Total Front (brake, 203mm rotor, 4 bolts, adapter) – 356.9 grams
- Total Rear (brake, 180mm rotor, 4 bolts, adapter) – 336.5 grams