New fully hydraulic models from SRAM, Formula/Colnago and possibly Shimano are capturing attention in the road and cyclocross disc brake world, but with many cable-actuated levers on the market, there's certainly a market for high-end mechanical options. TRP will answer the call this coming spring with two new models that will work with your existing levers.
Mechanical brakes go dual-piston with Spyre
While current mechanical options such as the Avid BB5 and BB7, Shimano CX-75 and Hayes CX-5 work well, they all are built with a single moving piston that flexes the rotor into a stationary pad. The new TRP Spyre, however, ups the ante with two moving pistons actuated by a single arm that wraps around both sides of the caliper.
This should yield better rotor clearance as well as a more consistent lever feel, especially as the pads wear. The Spyre does lack independent pad adjustments but the dual-piston motion and the integrated barrel adjuster should make that a moot point. Initial setup should be more straightforward, too.
TRP's Lance Larrabee offered no further information such as claimed weights, projected pricing or more technical details. However, the image suggests the Spyre is made of forged aluminum and we expect the impressively trim-looking shape to be lighter than current options. Based on TRP's earlier cantilever models, there's also a distinct possibility of a molded carbon fiber option to shed even more weight.
We also have no word yet on whether TRP will release multiple options to accommodate various cable throw ratios from Shimano, SRAM and Campagnolo, but again, the company has done so in the past with some of its conventional dual-pivot rim brakes so it's not an unreasonable expectation – particularly given that accommodating different cable pulls would require little more than a different bolt-on lever arm.
New HY/RD combines mechanical and hydraulic features
The new TRP HY/RD (pronounced "high road") is even more intriguing with a hybrid mechanical/hydraulic setup somewhat reminiscent of the old AMP Research caliper. A conventional brake cable is anchored to a short lever arm on the caliper, which then compresses a small plunger on the on-board master cylinder to clamp the two dynamic pistons on the rotor (AMP's system, on the other hand, directly clamped the cable to the cylinder plunger and relied on a single-piston, floating layout).
One might question why TRP would bother with something so complicated given that much of a hydraulic system's advantage lies in the way it efficiently transfers lever force into clamping power at the caliper. However, the HY/RD pads should self-adjust for wear – something no mechanical caliper does currently – the open hydraulic system should also maintain a consistent pad contact point, and the HY/RD should be lighter than current mechanical-to-hydraulic conversion systems such as from Hope, Tr!ckstuff and even TRP.
As with the Spyre, there's an integrated barrel adjuster on the HY/RD, but given the hydraulic system's self-adjusting nature we expect it to be more of a setup aid than anything else.
The HY/RD's name suggests that TRP intends this to be primarily a road product but we at BikeRadar expect it to appeal more to 'cross racers since the self-adjusting system should easily accommodate pad wear during a muddy race. Also, we can't help but question the tiny fluid volume's ability to cope with road riding's high heat dissipation demands as opposed to 'cross racing's far lower stresses but we'll reserve final judgment for when we've actually had a chance to sample it ourselves.
Either way, we're excited that TRP has devoted resources towards higher-end cable actuated systems that can be used with current levers. Both new brakes will be launched at the Sea Otter Classic in April.
Stay tuned for more information.