Tektro RX4.1

Tektro's RX4.1 is a purpose-built TT/triathlon brake lever designed for aero extensions and time-trial cockpit setups. The lever blade is forged from aluminum for a balance of light weight, stiffness and long-term durability, while the expanding plug clamp secures the lever inside aero bars with a 19.6–20.6 mm internal diameter.

The RX4.1 uses a simple, proven mechanical design: a forged lever blade, integrated return spring and reach adjust to fine-tune fingertip position. That combination delivers consistent braking modulation on both caliper and cantilever systems without complex mounting hardware — ideal for racers and committed triathletes who want reliable stopping power tucked behind the aero bars.

Built for aero bars: The RX4.1 uses an expanding plug clamp style that fits most clip-on or bolt-on aero extensions with an ID between 19.6 and 20.6 mm. Installation is clean and low-profile, keeping the lever secure inside the extension for a tidy cockpit.

Performance-focused details:

• Forged aluminum lever blade for strength and responsive feel.
• Return spring and reach adjustment to suit hand size and glove thickness.
• Compatible with caliper and cantilever brakes for broad brake system support.
• Black finish for a stealth, race-ready look.

The RX4.1 is specifically made for aero/tucked hand positions and fits aero extensions with an internal diameter of 19.6–20.6 mm. It accepts standard brake cables and is compatible with traditional caliper and cantilever brake types — the most common setups on time-trial and triathlon bikes.

These levers are sold as left and right positions and use a plug-style expansion clamp rather than an external band. That means they won't slide on properly on oversized or undersized bars, so verify your extension ID before buying. The RX4.1 is not designed for modern direct-mount road calipers that require integrated controls; instead it pairs with standard cable-pull caliper and cantilever systems.

The RX4.1 is aimed at triathletes and time-trial riders who want a durable, no-nonsense brake lever tucked into their aero extensions. It's a great option for racers on a budget who still want forged-aluminum construction and adjustability.

Choose the RX4.1 if you run traditional caliper or cantilever brakes on your TT bike or if you need a compact lever solution for training and racing setups where a clean, low-profile cockpit matters.

When shopping for TT/tri brake levers, prioritize clamp compatibility and adjustability. Measure the internal diameter of your aero extensions and confirm the lever's mounting method — expanding plug clamps like the RX4.1 deliver a clean, integrated install but require a matching ID. Check that your brake system is a standard cable-pull caliper or cantilever setup; direct-mount or electronic brakes may need a different solution.

Material and ergonomics matter: forged aluminum offers a reliable mix of stiffness and light weight, while reach and return-spring adjustments let you dial in fingertip position for long efforts. Finally, match new levers with fresh cables, housing and properly tuned calipers for the best stopping power on race day.