Originally Posted by
Chilepines
Hydraulic brakes are self-adjusting (or should be) so if the pads are not as close to the rotor and the lever feels soft, you probably need to bleed the brakes. You could also have a warped rotor causing what you are describing.
Discs are fine (dti clocked when the wheel were checked) , fluid was bled by a pro, yes twin pot calipers self adjust but I found that you can feel a difference when the pads start to wear. I used to feel the same on my race car with twin pots and no servo despite bleeding and reverse bleeding. When I fitted brand new pagid rs14, it was rock solid with very little pedal travel and after a couple of races, the travel was longer despite bleeding and use or 660 racing fluid.
Note that on the bike, the feel is not spongy, the braking power is still there and does not fade, the lever just travels more possibly because the pots retract back to much in the caliper housing. May be, when there is not pressure, the retracting springs are too strong causing the pads to retract back more than they really need. I have always wondered why Bike hydro calipers required those pad springs, cars don't need it and I don't believe motorbike have them either. Are these springs artefact of the mechanical disc system (like on some car hand brake/ebrake/parking brake)?
I also noticed that on the gorilla pads I currently use, the pots created an indent in the coating of the back plate (didn't get that on galfer or sram pads). I'm not to concern about that as it can help locating the pad on the piston/pot reducing potential movement /rattling when pressure is not applied. (known issue with AP twin pot calipers and the good old girling).