I’m pretty much the hydraulic disc brake novice having only owned 1 set after upgrading from mechanicals but I think I get the jist of it. You pull the lever, the volume in the resevoir reduces pushing the fluid out, fluid doesn’t compress so it forces the pistons out – voila. It’s relatively straitforward so I’m suprised at the supposed differences between different systems and the fact that there’s usually a new pad compound, braided hose, fluid additive etc. etc. that’s meant to make things even better.
Anyway, my situation is that I have a set of LX M585 brakes and levers which are fine for the sort of riding I do. The problem is however that they’ve got dodgy seals that harden up in cold weather preventing the pistons from retracting and they’re going to have to go before next Winter. Shimano say the the new M595s are a comparible system and that they’ve had no reported cold weather issues with them, so that’s probably the route I’ll go.
Money’s tight and I can get a M595 caliper for under £30. They’re compatible with my current levers, so £60 and I’m sorted. However, the levers are the old, pre-2007 design with the resevoir parallel to the bars and £60 and end will get me the new levers too (with the resevoir at 90 degrees to the bars). They look a lot nicer but do they add to the performance equation? With my simplistic view of things they all do the same thing, you pull the lever and push out the fluid.
Would I be shortchanging myself saving £60 by just using my old LX levers? I don’t think that the M595 levers have the servowave technology of SLX and higher groupsets, so it looks like it’s just the position of the resevoir.