TRP HY/RD Post Mount Disc Brake Caliper (Cable-Actuated Hydraulic)

Pronounced "High Road." The TRP HY/RD is the bridge between mechanical and hydraulic disc braking — a caliper that uses your existing cable-pull brake levers to actuate a hydraulic piston inside the caliper body. No new levers, no bleeding a full hydraulic system, no mineral oil reservoir on the bar. The same cables and housing you already have, delivering hydraulic performance at the caliper. Widely regarded as the most effective upgrade available for drop bar bikes with cable-pull levers that need more stopping power than a mechanical caliper can deliver.

How It Works — Cable In, Hydraulic Out
The HY/RD accepts a standard brake cable at the caliper body and converts that mechanical pull into hydraulic force through an internal open hydraulic system. The result is a caliper that squeezes both pads simultaneously from each side of the rotor — exactly as a full hydraulic caliper does — rather than the single-sided actuation of most mechanical disc calipers. The hydraulic force multiplication means more stopping power from the same lever input, with better modulation and more progressive feel than mechanical actuation alone. Riders who have switched from TRP Spyre mechanical calipers to the HY/RD consistently describe it as being approximately 80% of the way to full hydraulic performance — a meaningful step up that does not require replacing the rest of the brake system.

True Plug-and-Play — Compatible with Existing Levers
The HY/RD is designed for compatibility with Shimano and SRAM 11-speed road shift levers and all standard short-pull cable-pull brake levers — the levers already on your Passage Comp, Passage Expert, or Seymour Road build. No lever replacement required. Note: the HY/RD is not compatible with long-pull mountain bike style levers. If you are running MTB levers, see the TRP Spyre post mount in our range.

Hydraulic Reservoir — Automatic Pad Wear Compensation
An internal hydraulic reservoir automatically compensates for pad wear — as the pads wear down the caliper self-adjusts to maintain a consistent lever feel and engagement point. With a standard mechanical caliper you adjust cable tension as the pads wear. With the HY/RD you do not. The lever feel remains consistent across the full life of the pad.

Dual Piston — Both Pads Move Simultaneously
Both pistons advance from each side of the rotor simultaneously — even pad contact, even wear, consistent and centred braking force. The same dual-piston advantage as a full hydraulic caliper, driven by cable rather than fluid lines.

Semi-Metallic Pads Included — Shimano M525/M515 Compatible
TRP's own semi-metallic pads are included and compatible with all rotors. For riders who prefer a different pad compound, the caliper is also compatible with Shimano M525/M515 pads — a widely available aftermarket option. Note from user experience: the included TRP pads can wear quickly in sustained wet and muddy conditions. For year-round Vancouver wet-weather riding, Shimano M525 or Kool Stop pads are a recommended alternative.

Compressionless Housing Strongly Recommended
TRP and every experienced installer of the HY/RD strongly recommends compressionless brake housing for best performance — the hydraulic force multiplication in the caliper is only as good as the cable input that drives it. Standard spiral-wound housing compresses under load and absorbs energy before it reaches the caliper. Jagwire KEB-SL compressionless housing eliminates this entirely. We install KEB-SL on every HY/RD build at the Evercoast workshop — it is part of the job, not an optional extra.

Post Mount — IS Compatible via Adapter
Post mount caliper — mounts directly to post mount frames and forks. For IS mount frames and forks, an IS-to-PM adapter is required. Correct for the Evercoast Passage IS fork with adapter. For the Passage Pro flat mount frame and fork, see the TRP HY/RD flat mount variant.