🏍️ BREMBO 19RCS RADIAL BRAKE MASTER CYLINDER 110A26310 – FOLDING LONG LEVER TWIN DISC KBA-ABE CERTIFIED GENUINE ITALY
Ever grabbed your front brake lever hard into a corner, only to feel it go... mushy? Two rotor discs up front, two calipers gripping hard — yet the OEM master cylinder swallows all your input like a wet sponge. The braking power is there in the system, but the stock lever just cannot communicate it back to your fingertips. It is a common frustration among twin-disc sportbike riders: the hardware is capable, but the control interface is holding everything back.
The Brembo RCS 19RCS (110A26310) was engineered precisely for this scenario. Its 19mm piston displaces enough brake fluid to simultaneously actuate both front calipers on a twin-disc setup. Brembo's patented RCS (Racing Corsa Stradale) system lets you switch the lever ratio between 18mm and 20mm with a single 180-degree turn of a flat-blade screwdriver. 18mm for progressive street braking, 20mm for aggressive track response — two braking characters, one master cylinder. The body is forged aluminium (F.AL) with hard anodized (HA) surface treatment — the same manufacturing process Brembo applies in MotoGP. Folding long lever (195mm) distributes braking force across four fingers. This SKU carries KBA-ABE certification (TÜV approved), making it street-legal throughout the EU.
⚙️ TECHNICAL SPECIFICATIONS & CONFIGURATION – BREMBO RCS 19RCS GENUINE ITALY
📦 KIT CONTENTS
(per Brembo technical drawing dated 27.09.24)
🔩 GENUINE SPARE PARTS
⚠️ Note: Only genuine Brembo spare parts should be used — do not substitute third-party components.
🛠️ INSTALLATION GUIDE – CORRECT TECHNICAL PROCEDURE
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Step 1 – Preparation: Remove the OEM brake master cylinder, reservoir, and brake line. Protect all painted surfaces — DOT 4 brake fluid is extremely corrosive to paint on contact.
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Step 2 – Mount the Brembo RCS on the handlebar: The 110A26310 is designed for 22.2mm standard handlebars. Torque the handlebar clamp bolts to Brembo's specification — do not over-tighten, as this can deform the forged aluminium body.
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Step 3 – Connect the brake line: Install the banjo bolt (included in kit) to the fluid outlet port. Use the bleeder screw to purge all air from the system after filling with fresh DOT 4 brake fluid.
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Step 4 – Bleed and verify: Bleed the entire brake system until the lever feels solid with no sponginess. Verify brake light operation via the micro-switch included in the kit.
🚨 Critical installation notes:
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Never use solvents, gasoline, or thinners to clean the master cylinder body — use only water-based cleaners to avoid damaging internal rubber seals.
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All fluid ports must be capped during storage.
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Do not disassemble the master cylinder (piston, seals) — overhaul must be performed by Brembo.
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Use only genuine Brembo replacement parts.
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Replace the lever terminal immediately if it rotates loosely relative to the lever body.
🎛️ RCS LEVER RATIO ADJUSTMENT – OFFICIAL BREMBO PROCEDURE
The 110A26310 (RCS, type 18-20) allows switching the lever ratio between 18mm and 20mm. Identify the current setting by the push rod top face color:
8-step adjustment procedure (per official Brembo documentation):
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Step 1: With the master cylinder mounted on the bike, observe the push rod top face color (point 3). Red = 18mm, Black = 20mm.
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Step 2: Remove the rubber cap (point 4) from the lever body (point 2) by hand to expose the adjustment access hole (point 5).
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Step 3: Turn the lever-to-handlebar distance adjuster (point 6) fully counterclockwise to expose the adjustment slot (point 5) inside the hole (point 7).
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Step 4: If debris is present inside the adjustment hole (point 5), clean with a damp cloth. (⚠️ WARNING: Do not use compressed air).
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Step 5: Use a flat-blade screwdriver (point 8) with tip (point 9) width 3mm MAX, 2mm MIN — the tip must maintain this width for a minimum length of 12mm. (⚠️ WARNING: Do not use a screwdriver outside these specifications. Brembo accepts no liability for damage caused by non-conforming tools).
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Step 6: Insert the flat-blade screwdriver (point 8) into the adjustment hole (point 5) until it engages the slot (point 7). (⚠️ WARNING: Do not apply excessive force when turning or pressing the screwdriver — this can damage internal components).
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Step 7: Rotate the screwdriver 180 degrees until you hear a "click" — confirming successful switching. Verify the push rod top face color (point 3) matches the desired setting.
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Step 8: Replace the rubber cap (point 4). Adjust the lever-to-handlebar distance knob (point 6) to the preferred lever reach.
⚠️ CRITICAL WARNING: Lever ratio adjustment directly affects lever stroke and the brake pressure required to stop the motorcycle.
Functional test (mandatory after every adjustment):
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Verify that the lever pivots freely and generates proper braking force. If the lever binds, increase lever-to-handlebar distance via the adjuster (point 6).
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Perform a braking test at low speed to confirm effective braking before riding at normal speed.
🌟 PERFORMANCE & TECHNOLOGY
RCS (Racing Corsa Stradale) – Brembo Patented System:
The core technology of the Upgrade line. An eccentric locator mechanism allows switching the lever ratio between 18mm and 20mm using a flat-blade screwdriver, 180-degree rotation — no disassembly required. At 20mm (black push rod face), the brake responds quickly with a short lever stroke — suited for track use. At 18mm (red push rod face), the brake is progressive and linear with a longer stroke — suited for street riding.
19mm Piston – Optimized for twin disc (double disc) systems:
The 19mm piston displaces a large fluid volume, sufficient to simultaneously actuate both front calipers on a twin-disc system. Per Brembo catalogue: "The 19RCS must be used on twin disc systems with 4 non-floating small pistons."
LL – Long Lever:
The 110A26310 uses a long lever, distributing braking force across four fingers. Provides finer modulation and reduced fatigue on longer rides or sustained braking.
Forged Aluminium Body (F.AL):
CNC-machined from a forged aluminium billet. Compared to cast aluminium, forging produces a finer, more uniform grain structure — higher rigidity at lower weight. The surface receives hard anodized (HA) treatment — the same process Brembo applies in MotoGP and World Superbike.
How does braking feel change after the upgrade?
With the 19mm piston optimized for twin disc (double disc), the RCS 19RCS delivers markedly more linear brake feel compared to the OEM master cylinder. Finger input translates proportionally to caliper clamping force — the rider can sense the exact engagement point of the pads on the rotor, modulating brake intensity precisely without dead spots or abrupt grab.
🎯 COMPATIBILITY & FITMENT
The Brembo RCS 19RCS (110A26310) mounts on 22.2mm standard handlebars — compatible with most motorcycles.
Compatibility requirements:
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Motorcycle with twin disc (double disc) front brake system.
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Calipers: 4 non-floating small pistons (per Brembo technical requirement).
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Handlebar diameter: 22.2mm (standard).
Note: The 110A26310 is designed for twin disc (double disc) systems. For different disc configurations, see other RCS variants:
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110A26320 – 15mm, Short Lever, Single Disc
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110A26330 – 15mm, Long Lever, Single Disc
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110A26340 – 17mm, Long Lever, Twin Disc
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110A26345 – 14mm, Long Lever, Single Disc
💡 Not sure if this master cylinder fits your bike? Use the compatibility lookup tool on the Monkey89 website
