Parking it up for the winter.

[Darren69]

Looks like there is a version with a brake switch: -

https://www.ebay.co.uk/itm/BREMBO-RC....c100005.m1851

[Mr Gazza]

Have you had a look at what Ducati Paddy has got? http://www.ducatipaddy.com/page29.html

I've always found him to be very helpful and resourceful.

[FrankenDesmo]

Cheers for the reminders about reservoirs and switches - fortunately I already have a remote reservoir and the banjo bolt on the AP master has a pressure switch, though that is a good point about the thread so I'll check that it matches brembo in case I need it.

Anyway both kits that have been linked have switches and banjo bolts in them so I should be all good.

Originally Posted by Mr Gazza

Have you had a look at what Ducati Paddy has got? http://www.ducatipaddy.com/page29.html

I've always found him to be very helpful and resourceful.

I wasn't aware of him, no. I see he has the stock looking masters (the gold ones - remote reservoir), but what is the original unit? PSC16 seems like the most likely out of what's on that page, but then that would be 16mm vs 19mm on the ebay units. I don't have one here to measure though.

I will admit I am a bit taken by the darker colour of the 19RCS, and the "shiny & new" factor is nice, too. Of course I'll then have to get the matching clutch master

[FrankenDesmo]

Gah, I am terrible for asking a question and then going off and answering it myself... The stock master appears to be 16mm, so the PSC16 is likely the right unit. Which means the 19RCS is oversized - buuuut the AP Racing master is .875" which is ~22mm!

I doubt it matters much though, as I remember my first Monster stopped on a dime once I got the brakes sorted out (mostly a caliper rebuild, from memory).

Still leaning towards the 19RCS at the moment but I'm going to keep pondering as it's too late in the day to get one shipped.

[Mr Gazza]

It's not clear what year your bike is and what the original equipment would be.

For a single disc Ducati use a 13mm master (12.7 actually or 1/2") this moves enough fluid for 4 pots and gives sufficient leverage. For twin discs they used 15mm with the coffin type and then 16mm for the Goldline remote res ones. Goldlines would have come in about 1999.

A smaller master piston will apply more lever force to the caliper but will need more lever travel. a larger master piston will feel a bit sharper but need more finger pressure for the same braking force, it will have less lever movement.

When I had a 750SS with single disc and 12.7mm coffin master, I upgraded to twin discs, but retained the 12.7mm master. This resulted in a slightly larger lever travel but the force that could be progressively fed into those brakes was phenomenal. The feel and feedback was very good indeed. Power + control = the holy grail!

My personal preference would be to go for the 16mm master for better feel and more power. A 19mm is probably going to feel woody and not exert so much pressure.? (I have no experience of later brakes with larger masters, I can only assume that they are intended for bigger caliper pistons or more pots.)

Another factor in the mechanical advantage of a hydraulic system is the lever itself. The closer the pivot pin to the piston actuator, the more leverage it will give for more lever travel. I believe this leverage moment is adjustable on Radial masters? So you can get back the leverage that has been lost with a larger master piston.

[FrankenDesmo]

Originally Posted by Mr Gazza

It's not clear what year your bike is and what the original equipment would be.

...

Haha tell me about it. It started life as a 94 M600 but the only thing that remains M600 is the frame. The engine is an early V2, but the brakes could easily be 98+ as the clutch is a remote reservoir unit, though the brake has always been this AP Racing unit, which I have no history for other than AP themselves telling me it's a very early version, and they started production in the early 90s.

If I were to go back to "stock" (the term doesn't apply to my bike since it's a hybrid) then I'd consider that to be the 16mm Goldline master, as that's what I'm used to (I've not owned a coffin Monster).

That's interesting information re: piston/lever force/feel - the AP unit is definitely quite wooden, but I hadn't played with it's ratio adjuster yet, and it appears to be missing the knob for reach adjustment. I believe you're right about the ratio adjusters being there is bring some of the progressive feel of a smaller piston - it's also be what the 18-20 means for the RCS unit, the range of feel being 18mm - 20mm.

I remember being very impressed with the stock brakes on my 99 M900 once the calipers had been rebuilt. Maybe the 16mm is really the one to go for. Hmm.

[Mr Gazza]

I think the 16mm Goldline is going to be the best you will get, especially if you have the Goldline callipers, although I think the callipers are the same size as in the former model?

I'm not surprised that your 20mm AP feels woody, I don't think you're ever going to get any kind of fell into it however much you play with the lever moment.

The ratio of master to calliper is a complicated one to work out and it's worse as there are multiple pistons in the calliper of two diameters. It's way above my head to contemplate such maths, but rest assured it's been done at manufacture stage, and tested, which makes the original set up the most sensible.. It's surprising what a big difference a mil on the master will make.

[Dukedesmo]

Originally Posted by Darren69

Looks like there is a version with a brake switch: -

https://www.ebay.co.uk/itm/BREMBO-RC....c100005.m1851

Brembo RCS have a brake switch built-in, the earlier style Brembo radial (non adjustable ratio) don't - at least the one I have on my 916 doesn't, and so needs a banjo pressure switch.