In the world of mountain bike brakes, the larger players like Shimano and SRAM have been fairly quiet for a few years now, but on a smaller scale, boutique brands have begun to emerge. Radic Performance
is one of those which was created by Taylor Grey, an engineer based in Auckland, New Zealand. His interest in building a stronger mountain bike brake, such as the Kaha model, stems from a background in designing dual clutches and gearboxes for supercars.
The Kaha uses a fully machined four-piston caliper and master cylinder from 7075-T6 aluminum that has been optimized using Finite Element Analysis (FEA). That led to a system that is said to be light and stiff enough for the rigors of downhill, enduro, and e-bikes.
Starting at the lever, which pivots on stainless steel cartridge bearings, a 9mm master cylinder piston produces a smooth actuation through an easy-to-pull mechanic ratio over the course of a short dead stroke (the distance the lever travels to engage the pads). Titanium hardware secures the brake set to the bike and steel braided Goodridge lines are called upon for their durability.
At the caliper, there are two sets of stainless steel 16 and 17mm pistons which glide through PTFE dynamic seals. Taylor has chosen to use stainless steel for the piston material due to its low thermal conductivity, keeping the heat generated in the brake pads at bay from the fluid in the caliper. Even the oil flow through the caliper has been designed to pass all of the chambers sequentially, avoiding pockets where air may get trapped. That also allows for a full flush of the system when a bleed is performed. To achieve the best possible bleed, it’s actually advised that pads are left in the caliper to achieve that short dead stroke.
One of the most interesting bullet points on the Kaha brake is that it can be configured to use either DOT 5.1 fluid or mineral oil, plus the calipers utilize the commonly found Hope V4 pads.
In total, the system weighs 320g per side, including an 80cm braided line and pads. Each set of Radic Kaha brakes is machined and hand assembled in New Zealand for the tune of $1200 NZD. Australasia orders will commence first through the Radic Performance website
as of 6pm NZDT on November 9 with delivery expected by the end of 2022, with international shipments to follow in 2023.