Torx fasteners show up everywhere on modern bikes—brake rotor bolts, disc brake caliper mounts, derailleur mounting bolts, and increasingly on stem and handlebar interfaces where manufacturers want more engagement surface than hex keys provide. The Park Tool THT-1 set covers the sizes you'll actually encounter: T10, T15, T20, T25, T27, and T30. That range handles everything from the tiny T10 bolts on some brake lever clamps up through the T30 fasteners found on certain crank arm pinch bolts.

The sliding T-handle design gives you two grip options depending on the situation. Slide the handle to the center for high-torque applications where you need leverage—disc brake caliper mounts and rotor bolts that tend to seize from heat cycling and corrosion. Slide it to the end for speed when you're just running fasteners in or out. The crossbar grip generates significantly more turning force than L-shaped keys, which matters when you're breaking loose a stuck fastener without rounding off the star pattern.

Each wrench uses hardened steel for the Torx bit and handle, sized to match the expected load on that fastener size. The larger wrenches get longer handles because those fastener sizes typically see higher torque specs. Park Tool stamps the size on each handle so you're not squinting at tiny markings or guessing which wrench fits which bolt.... Read More