HEL Advocate 4-Piston Hydraulic Disc Brake System

Please note, that this is a temporary listing until our official launch in February 2025. This page will remain online until the exclusive pre-sale is sold out. All pre-sale orders will be delivered in January 2025.

The HEL Advocate brake system represents two years of relentless dedication to design, engineering, and testing. From initial sketches and 3D-printed prototypes to CNC machining, assembly, and extensive testing, every step has been completed entirely in-house by our team of engineers and riders. The result is a system that proudly encapsulates HEL’s 25 years of motorsport heritage. Purpose-built to meet the race demands of downhill and enduro, the Advocate will be HEL Mountain Bike's most capable, highest-performing, and robust brake system. Looking ahead, our vision includes the development of a 2-piston, ultra-lightweight radial brake specifically designed for the XC and trail market, complemented by Advocate accessories such as integrated mounts for gear shifters and dropper posts and an alternative lever blade.

The entire manufacturing process is completed in-house (Devon, England) using an array of the latest technology CNC machinery. This gives HEL full control over every step, leading to top-quality products. This commitment guarantees longevity and unwavering durability. Come and see for yourself. We actively welcome visitors with an open-door policy because we’re incredibly proud to show that we do what we say we do.

The difference between winning and losing can be an extremely fine line, which is why we focused on creating a brake system that excels in stopping power, precise modulation, and consistent performance. By collaborating with local riders and racers, we gained invaluable insights that directly influenced the Advocate's design. The result? A slightly firmer, direct lever pull, meaning you always know exactly where you stand in terms of power delivery - when it matters most.

The Advocate’s 2-piece billet caliper design features free-flow fluid channelling, which distributes pressure evenly to the pistons, enhances braking response, maintains optimal caliper temperatures, and effectively prevents brake fade, even on the longest descents.

HEL's stainless steel castellated pistons are desgined to optimise heat management by reducing the surface area in contact with the back of the brake pad. This innovative design directs more heat into the brake disc, minimising heat transfer to the caliper and brake fluid. Combined with the free-flow fluid circuit, this ensures the brake fluid stays at its optimal temperature, preventing overheating and brake fade. Whether you're racing or pushing your limits, the result is fade-free - run after run.

Every Advocate brake system comes with 2.7 metres (106") of clear or carbon braided stainless steel hose, paired with a world-first, two-piece HEL hose fitting kit (final production images coming soon) which is CNC-machined from stainless steel in-house. If your frame features internal hose routing, we highly recommend speaking with your frame manufacturer to confirm compatibility with our system (refer to the hose specifications below). Please note, the hose kit shown in the images is a temporary setup used exclusively for trail testing.

Make it your own. Every set of Advocate brakes is fully customisable at no extra cost using HEL's unique custom brake builder, available at launch on our official website. During the pre-sale phase, please select your preferred options and let us know if you have any questions.

Colour Options

Each customisable component is lightly sandblasted and then hard anodised, achieving a durable satin finish.

• Stealth Black
• Hyper Silver
• Vapour Grey
• Forged Bronze
• Helfire Red*
• Azure Blue*
• Plasma Purple*

*Caliper body, lever blade, lever adjuster, reservoir lid, and bar clamp only.

What's Included

• 2x HEL Advocate Master Cylinders
• 2x HEL Advocate Calipers
• 2x HEL Brake Pad Sets (Selectable)
• 2x HEL Solid Contoured Discs (Selectable)
• 1x HEL Braided Hose Kit (Selectable)
• 2x HEL Post Mount Adapters (Selectable)
• 1x HEL Advocate Bleed Block
• 1x Installation Manual

Bleeding the Advocate

Bleeding the brake system involves a straightforward two-syringe procedure, combined with a vacuum process to fully eliminate air from the free-flow caliper. Since DOT 5.1 fluid can be harmful to skin and brake bleeding can often get messy, we strongly recommend wearing gloves during the process and using isopropyl alcohol to clean your brakes, tools, and workspace afterward.

Before starting, ensure you remove the brake pads, but avoid contaminating the pad material, as this will compromise braking performance. If the lever feels spongy or lacks firmness after bleeding, this indicates there is still air trapped in the system. In this case, refill the syringes, gently tap the master cylinder, hose, and caliper with a plastic tool, and repeat the vacuum process until the system is fully bled.

Please note that the Advocate brake system is not pre-bled and is exclusively designed for DOT 5.1 brake fluid. Under no circumstances should you use mineral oil or any alternative brake fluids, as this will result in brake failure.

Warranty & Crash Replacement

Crashes are an inevitable part of riding, and we know bikes often end up slamming into trees or rock gardens, it's just part of the experience. We understand. That's why HEL offers a 12-month warranty on all Advocate brake systems, starting from the date of dispatch. In the unfortunate circumstance that your brake system is damaged in a crash, we're here to help you get back on the trail. In most cases, we can offer replacement parts at a discounted rate to cover the cost, or you can send your brakes to us for a rebuild and servicing.

Crash replacement is available only to the original purchaser and is non-transferable. You can use the service once within 3 years from the dispatch date. The replacement will be for the same model and size - swapping between different models or sizes is not permitted.

Testing the Advocate

HEL extensively tested the Advocate brake system in-house, in the lab, and on the trail to ensure performance and reliability. Each prototype underwent 250,000+ brake cycles on a fatigue tester, both at ambient temperature and with a direct heat source applied to the caliper, simulating a variety of conditions. In the laboratory, continuous and burst high-pressure fluid tests up to 1,000 psi (70 BAR) were conducted at various temperatures, demonstrating minimal deflection and outstanding strength under extreme loads. Finally, our team of riders subjected the system to thorough trail and race testing in real-world conditions, both wet and dry, to ensure it delivers no matter the challenge.

Check out the video below, where we documented a trail-testing session with Jay Williamson and Elliot Folland at our favourite local spot - Gawton Gravity Hub in Tavistock.

Specifications (Master Cylinder)

Specifications (Caliper)

Specifications (Hose)