My 900ss rear brake is pathetic, a Ducati specialist said they are not very good so I’ve never really bothered with trying to improve it other than bleeding it when I first got the bike, but I’m thinking it may need a bit more attention, it’s so poor I doubt it would lock the back wheel at 10mph, how good is yours?.
I stripped my calliper down, cleaned, greased and bled right through and it was actually not bad.. For about a week(100miles ish) then back to crap... It will just hold me on a hill at the lights and give me a small bit of low speed balance but that's it... tbh my monster and 748 ain't much better... The 749's rear was pretty good..
Mine was similar, but squealed very loudly when braking/filtering in traffic and everyone moved out of the way. So it was totalshite in power terms, but every one moved for me. There is also reassurance knowing it will not lock up in an emergency stop.
IME all the Ducati rear brakes are crap, they do not understand how to calculate the required ratios for the master cylinder vs caliper (or don't bother more likely) for the rear brake. If you want it to really work your options are to fit some or all of these: 1. Small internal-diameter rear brake hose (ie Hel or whoever). 2. Rear brake master cylinder with a larger piston size. 3. Rear caliper with smaller piston size. You should also deglaze your rear disk, fit decent sintered pads, and clean the caliper's pistons.
from what I gather although I could be wrong the main issue is the master cylinder is not up to the job as said incorrect size bore I believe there is 2 different master cylinders that where fitted each with a different size bore but on has a side exit and one with an end exit as they were for different model fittings think looking at the PDQ catalogue there is 11mm bore and 13mm bore
From my own experience, it's not the hydraulics that cause the problem, rather the disc material itself, which I guess is some sort of stainless. I tried different size master cylinders, and different types of pad, with no real improvement. However, I fitted Fireblade wheels to my SL ( I know, wash my mouth out, but they're cheaper and lighter than Marchesinis), and obviously have to use the Fireblade rear disc. Although it is also stainless, it must be a different, more appropriate grade, because with no other change to the system - same caliper, pads & m/cylinder - I've happily if accidentally now got a rear brake that actually works, and works well. Not suggesting that everyone should change to Honda wheels though!
my rear brake was rather dire but was better after a overhaul with new pads etc and a new armstong disc
Fitted a new master cylinder, bled it properly and it’s now “reasonable” (although I think the improvement was more down to the bleeding than the new master cylinder), I think from looking on this & other threads etc that the standard disc material doesn’t help and an aftermarket disc and HH pads would improve things, it’s OK though and at least it won’t lock up too readily in a panic braking situation so will do for now.
would agree that 748/9*6 under par for the job but never ever had a problem with any carb/belt SS rear brake in any of it’s derivatives. As long as disc has not overheated badly then softer compound pads are often the answer combined with (as already said) a braided/etc hose.
