Brake Anoraks Help Please

Discussion in 'Technical Help' started by Nasher, Mar 14, 2026 at 1:22 PM.

  1. When I fitted the 1098 forks into my 999 I picked up these front Calipers from somewhere, but can't remember where I got them from, or what they came off.
    They are the ones with the 4 small pads and have 4 x 35mm pistons, I think.
    Any idea what they could have come off?

    Brembos.jpg

    Anyway, why am I asking now several years down the line?

    I kept the original 999 Front master cylinder, which is 18mm, but I've never been really happy because there is hardly any movement at the lever and very little feel.
    I've noticed that the 999 master cylinder is actually weeping a little now, so it's an obvious opportunity to change it for something that may give a little more feel.

    If I knew what the Calipers were off I could target a master cylinder from that bike on Ebay.

    Does anyone know what bore size master cylinder those Calipers should be partnered with?

    What options do I have with regard to a suitable Master cylinder in 17mm or 16mm?
    What bikes come with that Master cylinder?

    In other words, does anyone have an encyclopaedic knowledge of Ducati/Brembo Brake Calipers, Master Cylinders, and what models they fit?

    Thanks
     
  2. BMW S1000RR looks favourite so far and depending on variations over the years, here is the master cylinder:- (2013 - more research will tell you the bore/stroke)

    [​IMG]
     
    • Agree Agree x 1
  3. From AI:-

    The 2023+ BMW S1000RR features a stock front brake master cylinder with a 17 mm piston bore. Upgraded or aftermarket options (like the Brembo RCS Corsa Corta) commonly use a 17 mm or 19 mm bore, with the RCS systems providing adjustable pivot distances (stroke/ratio) of 18 mm or 20 mm for personalized braking feel.


    [​IMG]
     
  4. Thanks all.
    Trawling ebay it looks like the 18mm Master cylinder is really common for Ducati models, but some later bikes have a 16mm.
    I've not considered other manufacturers at the moment, and do want to keep the non-remote type reservoir.

    So, are the Calipers I have anything special? If they are fitted to the 999R.
    I'd be surprised if I paid a lot of money for them, but perhaps that's where my mismatch lies rather than the master cylinder.
    I could always buy a set of less expensive Calipers and sell what I have on, because I really don't need anything too special for what I do with the bike.

    The lack of feel and no lever movement at the moment makes it harder to ride and is possibly more dangerous than a pair of more normal calipers, if that's where my issue lies.
     
  5. Could be from an Aprillia RSV or Tuono as they had gold versions of those calipers too.
     
    • Agree Agree x 1
  6. 999R or 749R ones are silver.
     
    • Agree Agree x 1
  7. Did I sell you these? I believe tuono if you had them off me. I have the same in black on the 749 track bike, off a 990 ktm.
     
  8. I assume these are what's known as Monoblock Brembo Calipers.

    I might swap them for a set of conventional Calipers I think I have hanging around and see if the feel is any better.
    If so I'll swap the Master Cylinder for another 18mm one and sell on the Monoblocks.
     
  9. I found those calipers had bags of feel on my 749R - not sure what the master cylinder diameter is but I would go with same as the R.
     
  10. Sorry I have no recolection of where they came from.
     
  11. Thanks, does anyone know what size MC the R uses?
     
  12. Calculate your brake ratio and optimise it: Determine the sum total area of your caliper pistons then divide that figure by the area of your master:
    • Soft feel — 30:1
    • Best feel — 27:1
    • Firm feel — 23:1
    • Wooden — 20:1
    Personally I love around 25:1 which is a 19mm master with the 34mm caliper pistons

    By the way - how do you buy pads if you don't know the type of caliper?
     
    • Like Like x 1
    • Useful Useful x 1
  13. It's about 30:1, but the lever hardly moves, the brakes are either on or off and the lever feels solid.
    But with no pressure on the lever the wheel runs really freely with no drag.

    I just brought the pads that come as a set of 4 rather than 2 per caliper.
     
    #14 Nasher, Mar 14, 2026 at 4:04 PM
    Last edited: Mar 14, 2026 at 9:48 PM
  14. That's quite strange, at 30:1 you should be in one finger lockup territory.. Better do some checking / measuring / servicing...
     
    #15 Neil66, Mar 14, 2026 at 6:12 PM
    Last edited: Mar 14, 2026 at 6:24 PM
Do Not Sell My Personal Information