Ducati Sporting Club UK > DesmoDue Race Series > DesmoDue - General Questions and Chat > Master cylinders

[Jonzi]

Evening

So I decided that I don't like the look of the coffin style master cylinders I have on the SS so bought some brembos (not radial though) off ebay.

Now I don't know if I have the right ones for my calipers!

How do I tell?

The master cylinders are stamped 105058 and 95 I think it says.

Again my googling is crap and I can't find what that means.

Any idea what the stamps mean and what size they might be?

Cheers!

Also, wrist not broken and having an MRI on my knee on Wednesday. Hopefully I'll be racing at Snetterton, if my wrist stops hurting by then.

[skidlids]

Ignore those markings they are usually in the casting. Sizes are stamped on and are quite small, Brake should have either 13, 15 or 16 depend what bike they are off and if it had single or twin disc
Clutch should have 12 or 13 depending on if its the later type or the earlier type with the large hollow pivot bolt

[Ghost]

Now Mr Jones, the interesting bit, your master needs to be sized to you calipers. Or you end up with no modulation, i.e that little bit of extra pressure = lockup on the front.

So calculate and sum the areas of your caliper pistons, then work out the area of your master cyl piston.

Divide master into caliper cumulative and ideally you want a ratio of 27:1 but can go down to 23:1 any less than that is not a good match and you could lock the front quite easily.

[Jonzi]

you lost me at "the interesting bit"

I now know what numbers are on the master cylinders, I assume that there will be something on the calipers?

If so I can post those and get more help then?

[Spjallen]

Trust me I'm an engineer?!!

[mat2hew]

my method is

1. fit master cylinder

2. test master cylinder

3. replace master cylinder if your not happy with it.

in all honesty I have fitted different types of master cylinders and they have all worked, some better than others, I think its as much personal preference as anything else, worst case you might end up with a lever that's very hard without much feel but with a brembo I doubt it. my preference is to lift the back wheel with 1 light touch of the lever with 1 finger. whereas I believe the pie man likes to bend levers (tough bloke from the North) before his bike stops.