Recommended Additional Upgrades
Why Choose RCB S1 17mm?
The RCB S1 17mm Radial Master Brake Pump is the heavy hitter of the S1 family. While the 14mm version is designed for standard small-capacity bikes, the 17mm is specifically engineered for high-performance setups that require moving a large volume of brake fluid.
If you are running the R1 4-piston caliper or a dual-disc setup, this is the master pump that provides the necessary hydraulic leverage.
With universal fitment, it is compatible with most motorcycles in Bangladesh, including performance bikes like Yamaha R15 V3, R15 M, MT-15, Suzuki GSX-R150, and also larger bikes with upgraded calipers.
RCB S1 17mm – Maximum Braking Power
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True Radial Design: The piston is positioned at a 90 degree angle to the handlebar. This direct alignment means that every millimeter of movement in your fingers is translated directly into braking pressure, offering world-class modulation and feedback.
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17mm Large Bore Piston: The 17mm diameter is significantly larger than standard (usually 12mm–14mm). It is designed to drive:
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Large 4-piston calipers (like the RCB R1).
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Twin-piston/Twin-disc setups on mid-sized bikes.
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Forged Alloy Construction: The body is forged rather than cast. This makes it incredibly strong and rigid, ensuring the body doesn’t “flex” when you’re pulling hard on the lever during an emergency stop.
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Remote Reservoir: It uses a separate, smoked-finish fluid tank connected by a hose. This allows for a more professional “racing” look and makes it easier to mount on bikes with tight fairing clearances.
When should you choose the 17mm?
Choosing the wrong size can ruin your braking experience. Here is the rule of thumb for the S1:
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Choose the 14mm: If you are using the stock caliper (1 or 2 pistons). Using a 17mm on a small caliper will make the lever feel “wooden” and extremely hard, with very little travel.
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Choose the 17mm: If you have upgraded to a 4-piston caliper (like the RCB R1 or Brembo 4P) or if your bike has dual front discs. The 17mm provides the volume needed to push all those pistons simultaneously with a firm, responsive feel.
The Performance Feel
With the S1 17mm, the “mushy” feeling of stock brakes disappears completely. You get a firm, high-pressure bite right at the beginning of the lever pull. It allows for “one-finger braking,” giving you more grip on the handlebar for better bike control.
Warning: Because the 17mm moves so much fluid, the braking response is very sharp. If you aren’t used to high-performance radial pumps, practice low-speed braking first to get a feel for the “instant” bite!
Are you planning to pair this with the R1 caliper we discussed earlier? That combination is widely considered the “Gold Standard” for high-performance underbone and sportbike builds.
