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Discussion Starter · #1 ·
I've see a few posts and sites that recommend upgrading the master brake cylinder.

Can anyone advise me what you gain out of this upgrade. (I currently have the standard cast iron floating discs and 2 pad front calipers on my F.E.)
 

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Old Wizard
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Aftermarket Brake Master Cylinders

The radial brake master cylinder will change the feel of the brakes by changing the hydraulic and mechanical advantage of the lever. They come in two versions and an adjustable version that can switch between two positions

They do not increase stopping power.

Make the choice of either 18mm or 20mm radial master carefully. The current after-market 19mm diameter master cylinders offer you the choice of a brake lever fulcrum-to-piston distance of either 18mm or 20mm. The stock Brembo lever has a 16mm dimension.

This different geometry means that the stock lever will need a lower pull force over a longer pull distance than the other two after-market MC’s to yield the SAME stopping power.

The 18mm lever will require 11% less pull force than the 20mm lever, but it also needs to be pulled through an 11% longer lever distance to get the same stopping force at the calipers. Conversely, with the 19X20 MC, you need to apply the highest pull force, but need the least lever movement to get the same amount of braking.

Some riders think that this short-pull trigger action means that they have "better" brakes, but they don't - at least not for street riding conditions.

http://www.ducati.ms/forums/showthread.php?p=662289#post662289
 

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I have the stock master cylinder and stock cast iron SP front rotors with galfer green pads and the 65 mm 2-pin calipers (I put these on because I switched to Superbike forks which won't work with the stock 40 mm caliper bolt spacing). I would not want more power; they are strictly 2-finger brakes which will do stoppies no problem if I'm not careful at the track. I would think even with the stock calipers you would still get plenty of front braking! Try the Galfer greens; they're easy on the unobtaineum cast iron rotors too.
Joe
 

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I've got 4 pad/4 piston brake calipers (off a 996R) (with 40mm to 65mm adapters for my stock fork) and a Brembo radial master cylinder. The master cylinder has much better feel than the stock, which may not add braking power, but it sure does feel like it. I'm considering Braketech rotors, maybe iron, maybe carbon ceramic. I don't remember the master cylinder bore off the top of my head, but I can verify it if you'd like.

I'd suggest this combination as a very good upgrade but if I were to do it today I'd get the new Brembo RCS (or whatever it's called) master cylinder as it has provisions for a brake light switch (I use a pressure switch).

As mentioned above, make sure you're using fully organic, non sintered brake pads with the cast iron rotors.
 

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I've see a few posts and sites that recommend upgrading the master brake cylinder.

Can anyone advise me what you gain out of this upgrade. (I currently have the standard cast iron floating discs and 2 pad front calipers on my F.E.)
The diameter of the cylinder, doeas affect the leverage you have over the calipers, so yes it will have an impact if you go with a diff diam cylinder. For me, it's more about bleeding, than anything else. You shouldn't need to change the diam of the MCyl.

I swapped out for SPS brake and clutch masters. The cool thing about the SPS brake master is that it has a dual chamber design, which really improves bleeding.

My brakes are eye-popping. FAR superior to the stock setup.

Here's what I have:
SPS Master
SS Lines
Nissin 6-pot calipers
Brembo 'snowflake' rotors
 

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P.S. dollar-for-dollar, upgrading the master to say a Brembo billet for example, is a complete waste of money if outright performance is your goal. If bling is your goal, then hell yeah!

But, Ducs have 330mm discs which is about as big as it gets and gerat Brembo masters stock. So, if performance is still an issue, as it was for me, spend the money on calipers. That's where your power comes from.

Disc/pad combinations can have an enormous impact too. It's a bit of a black magic.
 

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Ducs have 330mm discs which is about as big as it gets
Most recent Ducs have had 320mm discs, I think the switch to 330mm was only on the 1098's/1198's. Still a lot bigger than most sportbikes which have a lot of 300-310mm discs.

If you're wondering about which leverage/bore ratio in the radial master cylinders you'll like best, get the Brembo RCS master cylinders, you can switch between 19x18 & 19x20 without changing the whole master. I've got them on my SS, they're pretty nice. So far I've been running it at the 19x20 setting, will be switching to 19x18 in a week or so to compare.

Feedback I've heard on the difference is 19x18 has a more power due to the leverage increase, and is recommended more for track use, 19x20 has a better "feel" (although that is probably subjective) and is better for most street riders.
 

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Discussion Starter · #8 · (Edited)
P.S. dollar-for-dollar, upgrading the master to say a Brembo billet for example, is a complete waste of money if outright performance is your goal. If bling is your goal, then hell yeah!

But, Ducs have 330mm discs which is about as big as it gets and gerat Brembo masters stock. So, if performance is still an issue, as it was for me, spend the money on calipers. That's where your power comes from.

Disc/pad combinations can have an enormous impact too. It's a bit of a black magic.
Thanks for all the help so far.

I've already got stainless lines and Ferodo Platinum organic pads. I've got the standard single pad master cylinders. (whoops Muschi is right I meant to say calipers!)

I seem to have enough power in the brakes (I guess you can't be sure until you have had more though).

What I am keen to get a feel for is whether radial master cylinders will give me better feel and modulation?

Or would a change to the four pad master cylinders be a better way to increase feel and modulation?
 

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you seem to confuse the terms master cylinder and calippers,
the things at the wheels are the calippers, yours have got 4
pistons each too, they are just a little smaller than the P4 34/34
ones, the master cylinder is mounted at the handlebar.
 

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Discussion Starter · #10 ·
you seem to confuse the terms master cylinder and calippers,
the things at the wheels are the calippers, yours have got 4
pistons each too, they are just a little smaller than the P4 34/34
ones, the master cylinder is mounted at the handlebar.
Thanks Muschi, I've corrected my previous post.

Musci I thought that both the early and later calipers had four pistons. But I thought the later ones had four pads Vs the earlier model calipers 2 pads?
 

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Muschi I thought that both the early and later calipers had four pistons. But I thought the later ones had four pads Vs the earlier model calipers 2 pads?
supersport and superbike calipers both have four pistons each, that's true,
but supersport calipers always came with two pads per caliper.
superbike calipers had 4 pads for a short time only, these calipers are
easy to detect visuably.
they are found on the 999 as far as i know, maybe some late 998 too,
1098 monoblocs got 2 pads per caliper only.

supersports have got P4 30/34 calipers, instead of the P4 34/34 ones
from the superbikes, that is why supersports came with PS 16 masters
and not 18mm masters like the superbikes did.
It is a matter of surface ratio between the added caliper pistons and the
surface of the master cylinder.
 

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Discussion Starter · #12 ·
supersport and superbike calipers both have four pistons each, that's true,
but supersport calipers always came with two pads per caliper.
superbike calipers had 4 pads for a short time only, these calipers are
easy to detect visuably.
they are found on the 999 as far as i know, maybe some late 998 too,
1098 monoblocs got 2 pads per caliper only.

supersports have got P4 30/34 calipers, instead of the P4 34/34 ones
from the superbikes, that is why supersports came with PS 16 masters
and not 18mm masters like the superbikes did.
It is a matter of surface ratio between the added caliper pistons and the
surface of the master cylinder.
Is there an advantage in that there is less 'mounting flex loss' in a radial set up?

All other things being equal (fulcrum and piston area ratios) a lever/master cylinder mounting with less flex should in theory provide better feel.

Has anyone out there used a radial mounted master cylinder with the older calipers?

If so does reality match my half baked theory?
 

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I have the stock master cylinder and stock cast iron SP front rotors with galfer green pads and the 65 mm 2-pin calipers (I put these on because I switched to Superbike forks which won't work with the stock 40 mm caliper bolt spacing). I would not want more power; they are strictly 2-finger brakes which will do stoppies no problem if I'm not careful at the track. I would think even with the stock calipers you would still get plenty of front braking! Try the Galfer greens; they're easy on the unobtaineum cast iron rotors too.
Joe
Joe,

Are the cast iron SS/SP/FE rotors no longer available?
 

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Old Wizard
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Conventional (Axial) vs. Radial Master Cylinders



Radial and conventional/axial master cylinders differ in the orientation of the piston relative to the handlebar and to the pull direction of the lever. The conventional design places the piston axis parallel to the handlebar and perpendicular to the lever pull direction. The radial design puts the piston axis parallel to the lever pull direction and perpendicular to the handlebar. Radial and axial master cylinders are functionally the same.

The main advantage of the radial design per se is that it moves the lever pivot point inward toward the centerline of the bike so that the same pull force develops a smaller moment about the connection point to the handlebar. This reduction in bending moment should result in less flexing of the master cylinder housing. Any reduction in flexing of brake parts such as in the lever, MC housing, brake lines, calipers and caliper mounts add up to better brakes with better feel (modulation.) Also, aftermarket radial designs are generally stronger than the OEM designs because they are machined from alloy billet material.

The main reason (other than appearance) that Ducati owners replace the factory set-up with a radial aftermarket unit is to obtain a different MC piston size (hydraulic ratio) and lever pivot point distance (mechanical ratio.)

Given all that, the radial design should allow for some weight reduction by Brembo's engineering department because the material stresses in a radial design are lower for the same applied lever forces.

But, as far as I'm concerned, this weight savings, if any, isn't enough to justify replacing the OEM levers. If the trend continues, your next bike will probably have them as original equipment.

The general rule to follow is reduce rotating weight first, unsprung weight second, and everything else later. You save the most by first replacing those components that are the heaviest.

My choice would be to change to an AXIS ductile iron rotor having a higher coefficient of friction and therefore more stopping power, combined with a lighter weight rotor (that saves about one pound per rotor) having less unsprung weight and rotational inertia, giving better handling.
 

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The only clear advantage of upgrading to radial is the clearance you gain for clipons. Aluminum clipons are much thicker than the stock steel ones. I had a clearance issue with my brake side but not the clutch (SMP clipons). If I ever bust the ones I have now I will switch to radial pumps for this reason only.
 

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check with motowheels for cast iron rotors
 

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Well here is my 2-cents........ over the years I've gone from coffin master cyl to the gold with remote resivor, upgraded to kevlar lines, this all worked much better than stock for street rides, then I found the track....... Only took a few track days and having the lever go to the bar on hard braking for me to upgrade to 19 X18 radial master that was the single best up-grade I ever made, I now run same stock calipers, ceramic/kevlar pads/steel braid lines and the 19X18 master..... I have never had a sinlge brake related issue ever in my threee years of track abuse.....and I don't care what anyone here says those radial masters do increase braking performance.....maybe overkill for street rides but I swear by them for the track
 

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A cheap and effective m/cyl. upgrade is a Nissin 5/8 cyl as used on countless thousands of jap sportbikes.Properly bled and with EBC HH pads it will allow controllable monowheeling if desired and all at a cost of about US$100.I've had one on my 91SS racebike for the past 17yrs. and can loft the rear wheel with my not insignificant 240lb.firmly planted in the seat.But if you want bling go with the Brembo radial cyl.
 
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