I posted sort of the same thing when the topic came up in a Colnago related thread but probably should have more appropriately posted it here....
Do you see any advantage to the DM brakes, say Shimano latest DM brakes compared to Shimanos latest 9100 standard mount brakes?
- Clearance?... Not really. If clearance was really an issue and you want to run 30mm+ tires (28's fit just fine under the standard mount 9100 calipers), I would think you'd want disc brakes over either standard or DM rim brakes.
- Stiffness: After installing a few 9100 standard mount calipers, I can't see great gains being made there from DM brakes, at least not any that would make one bit of difference. The standard mounts are very very stiff. I don't think any more would be a noticeable improvement in performance.
- Simplicity: Nothing is as simple to install and maintain as a standard mount dual pivot caliper. There are some that say the standard mount calipers are more prone to getting knocked off center. I have to wonder if those calipers are properly torqued to the frame. I tried moving my calipers off center, and it is not easy. A simple knock of the wheel during removal and install would not do this for sure. In any case, that has certainly never been an issue for my bikes. So for Shimano: 8-10Nm, Campagnolo: 10-12Nm. Check it. With a torque wrench. Then see how easy they get knocked off center.
I'm just having a really tough time seeing any actual real benefit to a DM brake, over the current crop of Standard mount brakes (especially the Shimano 9100). I think the brake choice these days is really between rim calipers or discs, and for the rim brakes I think I'm still preferring the standard mounts given some of the convoluted contraptions I've seen in the direct mount space... so ugly and unrefined looking and in some cases, much more finicky to set up.
Have you used DM Brakes yourself? Determining whether they are stiffer by looking at them isn't the best method.
I have not used them, ordered a Transonic frameset this week. If there is no advantage, well, I won't be sad. I'll be happy if they just perform as well as current single mount brakes.