The Sumart Universal Bleed Block (UBB-20) is an essential workshop tool designed to safeguard delicate ceramic pistons in 2-piston hydraulic brake calipers during the bleeding process, combining flawless adjustment with a vibrant range of colours.
The Sumart UBB-20 Universal Bleed Block is an indispensable addition to any home mechanic's workshop or professional service bay. Specifically engineered for 2-piston hydraulic disc brake calipers, this premium tool acts as a solid physical barrier when your brake pads are removed. By maintaining the correct spacing between the pistons during a brake bleed, it prevents fluid overfill and stops the pistons from accidentally advancing or popping out of their bores.
One of its most critical features is its material composition, which is specifically designed to protect delicate ceramic pistons—commonly found in modern Shimano and SRAM high-performance brakes—from cracking or chipping under pressure. Unlike crude, generic plastic wedges, the UBB-20 features a highly adjustable design. It can be easily tightened or loosened entirely by hand via the knurled dial, or fine-tuned using a standard 3mm Allen key when working within tight clearances. Machined to perfection, it is available in a wide variety of anodised colours, allowing you to add a touch of custom style to your digital toolboard or travel toolkit.
Ceramic Piston Protection: Engineered from materials that absorb and distribute force evenly, preventing expensive damage to brittle ceramic caliper pistons during maintenance.
Precision 2-Piston Compatibility: Tailored specifically to standard 2-piston hydraulic configurations, ensuring a perfectly square, snug fit inside the caliper body.
Tool-Free Manual Adjustment: Features an integrated thumb dial that allows for quick positioning and secure hand-tightening without reaching for external tools.
3mm Hex Key Integration: Includes a low-profile 3mm Allen key socket for scenarios where tight frame or fork clearance makes manual finger adjustment difficult.
Universal Fluid Resistance: Constructed to withstand constant exposure to corrosive DOT fluids and mineral oils without degrading, stripping, or warping over time.
Anodised Colour Variety: Blends ultimate workplace functionality with custom style, available in Black, Red, Blue, Gold, Purple, Orange, and Pink.
Model Number: UBB-20
Caliper Compatibility: 2-Piston Hydraulic Brake Systems
Adjustment Methods: Manual Thumb Dial / 3mm Allen Key
Material: Heavy-duty fluid-resistant compound and anodised alloy
Available Colours: Black, Red, Blue, Gold, Purple, Orange, Pink, Green
Own Modern Hydraulic Brakes: Perfect if you run high-end Shimano or SRAM systems with ceramic pistons that are notoriously easy to chip with flathead screwdrivers.
Value a Clean, Safe Bleed: Ideal for riders who perform their own fluid flushes and want a rock-solid block that guarantees accurate oil volume without leaks or overfills.
Appreciate Micro-Adjustments: The dual hand-and-tool adjustment means you can adapt the block width perfectly to varying caliper depths and tight frame designs.
Love Colour-Coded Tools: Great if you want to quickly spot the right tool in a messy toolbox or match your workshop setup to your bike's colour scheme.
Need Universal Adaptability: Works flawlessly across multiple bike disciplines, whether you are servicing 2-piston XC mountain bikes, gravel rigs, or road disc setups.
Running DH or Enduro Rigs: Designed exclusively for 2-piston setups; if you run heavy-duty 4-piston downhill or enduro brakes, you will need the wider UBB-40 variant instead.
Only Need a Basic Wedge: If you only bleed your brakes once every few years, a cheap, non-adjustable plastic plastic block might suffice for a basic service.
Own Mechanical Disc Brakes: Completely redundant for cable-actuated systems, as mechanical calipers do not utilise hydraulic fluid or advancing pistons.
Before inserting the Sumart UBB-20 into your caliper, always use a clean, non-marring tool (like a plastic tyre lever) to push the pistons completely flush and flat back into their bores. Once the bleed block is inside, use the thumb dial to expand it snugly against both pistons. This completely locks them in place, guaranteeing that when your bleed is finished and you reinstall your brake pads, you will have the perfect amount of rotor clearance and a crisp, immediate lever feel without any annoying brake rub!
