Hayes doesn’t claim to have created the lightest brakes on the market, but at 257 grams per wheel, the T4s are around 40 grams lighter than SRAM codes and 5 grams lighter than Shimano’s XTR 4-piston brakes. The brakes aren’t usually the first place most cyclists go to shed some weight, but if the power and performance remain the same, it certainly doesn’t hurt to knock a few extra grams off the scale.
• 17mm plunger
• Range adjustment, pad contact adjustment
• Claimed weight: 257 grams (90 cm hose + mounting hardware)
• DOT 5.1 fluid
• Price: 325 USD per brake
The spec sheet claims that adjusting the T4’s reach is still a tool-free affair, but that doesn’t seem to be the case – the dial found on the aluminum lever blade is nowhere to be seen on the carbon blades, which are produced by Reynolds, Hayes’ sister company. The adjustment of the reach of the lever and the contact of the pad is always possible, you will only need to use an Allen key to make these adjustments.
All the other Domain features are still in place – the brakes use DOT 5.1 fluid, with four 17mm pistons in each caliper. The caliper body has undergone additional machining to remove any excess material, and there are small depressions on either side that are probably worth a few grams of weight savings. Fortunately, the set screws that help align the caliper perfectly haven’t gone anywhere – this clever feature helps set the Domains apart from other brakes on the market.
The Dominion T4’s bolts, push rods, compression and banjo fittings are all titanium, and there are composite reservoir covers to lighten things up even more, along with aluminum back plates over the brake pads. .
Unsurprisingly, all that carbon fiber and titanium raises the end price—the Dominion T4 brakes are priced at $325 USD per wheel, compared to $250 for the Dominion A4. Aluminum-backed T4 pads are $38.99 USD.