Hi. Have xtr brakes on a 2014 camber that the mrs rides occasionally, there's often several months gap because biking comes a distant second to running nowadays. The brakes at both ends each time it comes out just don't work, it's like they have been contaminated but there's no indication of a fluid leak and the levers are solid. Pull the levers on hard as you like and you can push the bike forward with force and there's loud squealing out of both ends.
I go through the process of cleaning the pads and rotors up and it all works ok again but then gets left a few months and we have the same problem. Anyone aware if there is an issue with the rotors or will the race matrix pads be incompatible with them? Never had any problems with steel rotors or any other brakes with this problem for that matter in over 20 years.
Thanks
Have they been overheated, sometimes rotors can get slightly glazed, meaning they've lost the friction they usually have, not easy to restore if it is this, a fine sandpaper block might do the trick, but again, hard to get the same overall finish you would by getting new rotors.
What argee said. Same happened to a 160mm icetec rotor I was using. Solved by going to 203mm.
My bet is that your calipers have micro leaks. Appearing contaminated after being left is a classic symptom. Save yourself the hassle and just replace them (cheap guides on CRC currently).
there’s no indication of a fluid leak and the levers are solid.
I get this. There might be micro leaks or it might be the general oily nature of things in my garage - airborne particles from spraying lube and whatnot.
To clean them up though just douse in bike cleaner eg. Halfords, ride a few yards with the brakes in to rub it in, then hose clean. That's all I do and it's been as effective as a full strip and de-grease but far quicker.