🏍️ BREMBO 15RCS RADIAL BRAKE MASTER CYLINDER 110A26320 – FOLDING SHORT LEVER SINGLE DISC GENUINE ITALY

Riders with smaller hands on single-disc motorcycles face a specific problem: the OEM brake lever is too long, forcing fingers to stretch just to reach adequate stopping power. Two-finger braking on an oversized lever means the grip point keeps shifting, and modulation becomes guesswork rather than precision. It is not just uncomfortable — inconsistent brake feel undermines confidence in every traffic situation.

The Brembo RCS 15RCS (110A26320) pairs a short lever (168mm) with a 15mm piston optimized for single-disc systems. Compact two-finger operation with light pull and linear feedback. The RCS system provides 18-to-20mm lever ratio adjustment via screwdriver — no disassembly required. Forged aluminium body (F.AL), hard anodized finish (HA), and the kit includes a brake light micro-switch for street use.

⚙️ TECHNICAL SPECIFICATIONS & CONFIGURATION – BREMBO RCS 15RCS GENUINE ITALY

ATTRIBUTE	TECHNICAL SPECIFICATION
Brand	Brembo – Italy
SKU / Part Number	110A26320
Product Line	Upgrade – RCS
Full Product Name	RCS Forged Radial Brake Master Cylinder
Mounting Type	Radial – handlebar-mounted
Body Material	F.AL – Forged Aluminium
Surface Treatment	HA – Hard Anodized
Piston Bore	15mm
Lever Ratio	18 – 20mm – adjustable via RCS eccentric locator
Lever Type	SL – Short Lever (Folding)
Disc Configuration	Single Disc
Weight	450g
Overall Dimensions (L x H)	168mm x 129,5mm (from Brembo technical drawing dated 27.09.24)
Handlebar Bore	22.2mm (standard)
Brake Fluid	DOT 4
Brake Light Micro-switch	Included in kit
KBA-ABE Certification (TÜV)	No
Product Category	Radial Brake Master Cylinder
Classification	Aftermarket – Upgrade Line
Condition	Brand New 100% Full Box
Color	Black – Hard Anodized
EAN Barcode	8020584607237
Packaging Unit	1 set / box
Country of Origin	Italy – Brembo S.p.A.

📦 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.

🌟 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.

15mm Piston – Optimized for single disc systems:

The 15mm piston provides fluid displacement matched to the piston travel of single-disc calipers. Per Brembo catalogue: "The 15RCS can be mounted on single-disc units with a 4-piston caliper, or twin-disc with floating type calipers."

SL – Short Lever:

The 110A26320 uses a short lever, overall length 168mm (vs. 195mm for the long lever variant). Suited for riders with smaller hands or those preferring compact two-finger operation (index + middle finger).

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 15mm piston optimized for single disc, the RCS 15RCS 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.

🛠️ INSTALLATION GUIDE – CORRECT TECHNICAL PROCEDURE

1. 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.

2. Step 2 – Mount the Brembo RCS on the handlebar: The 110A26320 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.

3. 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.

4. 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:

• Never use solvents, gasoline, or thinners to clean the master cylinder body — use only water-based cleaners to avoid damaging internal rubber seals.

• All fluid ports must be capped during storage.

• Do not disassemble the master cylinder (piston, seals) — overhaul must be performed by Brembo.

• Use only genuine Brembo replacement parts.

• Replace the lever terminal immediately if it rotates loosely relative to the lever body.

🎛️ RCS LEVER RATIO ADJUSTMENT – OFFICIAL BREMBO PROCEDURE

The 110A26320 (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):

1. Step 1: With the master cylinder mounted on the bike, observe the push rod top face color (point 3). Red = 18mm, Black = 20mm.

2. Step 2: Remove the rubber cap (point 4) from the lever body (point 2) by hand to expose the adjustment access hole (point 5).

3. 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).

4. Step 4: If debris is present inside the adjustment hole (point 5), clean with a damp cloth. (WARNING: Do not use compressed air).

5. 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).

6. 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).

7. 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.

8. 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):

• 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).

• Perform a braking test at low speed to confirm effective braking before riding at normal speed.

🎯 COMPATIBILITY & FITMENT

The Brembo RCS 15RCS (110A26320) mounts on 22.2mm standard handlebars — compatible with most motorcycles.

Compatibility requirements:

• Motorcycle with single disc front brake system.

• Calipers: 4-piston for single disc, or floating-type for twin disc.

• Handlebar diameter: 22.2mm (standard).

Note: The 110A26320 is designed for single disc systems. For different disc configurations, see other RCS variants:

• 110A26310 – 19mm, Long Lever, Twin Disc

• 110A26330 – 15mm, Long Lever, Single Disc

• 110A26340 – 17mm, Long Lever, Twin Disc

• 110A26345 – 14mm, Long Lever, Single Disc

💡 Not sure if this master cylinder fits your bike? Use the compatibility lookup tool on the Monkey89 website — enter your bike brand, model, and year for an instant match