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350TSS · 17-02-2019, 03:48 AM

Unashamedly copied from the other forum - but useful info I think:

"One important design consideration when you select braking components is the cross sectional area of the master cylinder in relation to the total area of the caliper pistons. This determines how much the pull force at the lever is multiplied at the calipers and is directly related to the “feel” at the lever. If the total caliper piston area divided by the MC piston area is too large, the lever has a soft feel; too small, and the lever feels wooden and lacks feedback about what the brakes are doing. There’s an area ratio that most agree gives good modulation characteristics: about 27.

Here’s a rough scale for (two caliper) lever feel/modulation.

30:1 — soft
27:1 — sweet
23:1 — firm
20:1 — wooden

Early 916 SP/SPS Ducati braking systems were purposely biased toward a soft lever feel, probably to reduce the likelihood of brake lock-up when emergencies arise on the street. Preference for a certain lever feel is somewhat subjective, so a different hydraulic ratio may be preferable for some riders.

In particular, a Ducati 916SP has a 16 mm master cylinder (201 mm²) and P4 30/34 Gold Series calipers (6459 mm²) giving it a ratio (6459/201) of 32, quite soft.

If you change to a 18 mm (254.5 mm²) Hypermotard master cylinder you’ll get a ratio (6459/254.5) of 25.4, a bit firm.

If you change to a 19 mm (283.5 mm²) RCS master cylinder you’ll get a ratio (6459/283.5) of 22.8, a bit wooden.

If you change to a 17 mm (227 mm²) RCS master cylinder you’ll get a ratio (6459/227) of 28.4, a bit firmer than stock and closer to ideal. This is the ratio that Ducati uses on the 749, 999, 1098, 1198, Streetfighter, and Multistrada Pikes Peak S. This would be my choice for a 916 SP."

17-02-2019, 03:48 AM	#1
350TSS Too much time on my hands member Join Date: Jan 2013 Location: Shipbourne Bike: M900 Posts: 1,419	Master cylinder feel Unashamedly copied from the other forum - but useful info I think: "One important design consideration when you select braking components is the cross sectional area of the master cylinder in relation to the total area of the caliper pistons. This determines how much the pull force at the lever is multiplied at the calipers and is directly related to the “feel” at the lever. If the total caliper piston area divided by the MC piston area is too large, the lever has a soft feel; too small, and the lever feels wooden and lacks feedback about what the brakes are doing. There’s an area ratio that most agree gives good modulation characteristics: about 27. Here’s a rough scale for (two caliper) lever feel/modulation. 30:1 — soft 27:1 — sweet 23:1 — firm 20:1 — wooden Early 916 SP/SPS Ducati braking systems were purposely biased toward a soft lever feel, probably to reduce the likelihood of brake lock-up when emergencies arise on the street. Preference for a certain lever feel is somewhat subjective, so a different hydraulic ratio may be preferable for some riders. In particular, a Ducati 916SP has a 16 mm master cylinder (201 mm²) and P4 30/34 Gold Series calipers (6459 mm²) giving it a ratio (6459/201) of 32, quite soft. If you change to a 18 mm (254.5 mm²) Hypermotard master cylinder you’ll get a ratio (6459/254.5) of 25.4, a bit firm. If you change to a 19 mm (283.5 mm²) RCS master cylinder you’ll get a ratio (6459/283.5) of 22.8, a bit wooden. If you change to a 17 mm (227 mm²) RCS master cylinder you’ll get a ratio (6459/227) of 28.4, a bit firmer than stock and closer to ideal. This is the ratio that Ducati uses on the 749, 999, 1098, 1198, Streetfighter, and Multistrada Pikes Peak S. This would be my choice for a 916 SP."