Interbike 2011: Ashima brakes evolving

New caliper, diaphragm and rotors

Ashima are currently in the midst of improvements to their PanCake Brake (PCB) with the aim of giving it a more conventional feel. New diaphragms and caliper design are currently being worked through, as the manufacturer also readies two new rotors for sale in 2012.


As a refresher, Ashima disc brakes are piston-less: Instead of conventional pistons, a rolling diaphragm seal pushes the pads to the rotor. It’s a unique design that keeps their weight very low (308g claimed) and gives them a unique feel.

In the year the brake has been on the market, Wayne Moore, the Taiwanese manufacturers’ general manager, says riders have come to either love or hate the feel.

In an effort to give the brakes a more conventional feel for 2012, they’ve co-molded PTFE reinforcement on the high temperature Viton rubber diaphragm to make it stiffer. Besides ‘bettering’ the feel, according to Moore, the new diaphragms work with any type of brake fluid on the market from all types of DOT fluid to mineral oils.

The new caliper is a one-piece monobloc style unit and integrates Ashima’s fluid transfer tube so that it needn’t be removed during a service, as the current design requires. The new design is even thinner, says Moore.

Ashima’s new prototype monobloc caliper:
Matt Pacocha/BikeRadar

Ashima’s new prototype monobloc caliper

In addition to the new diaphragm and caliper, Ashima have rolled out a new range of multi-piece rotors. The three-material D-Matrix is built to minimize weight, the 160mm model is said to weigh just 60g. Ashima showed a prototype last year and have since added tabs to mechanically attach the two steel-braking surfaces to the carbon-reinforced alloy carrier.

The three-piece Spider Rider rotor is engineered to maximize its performance as a heat sink. The latter sandwiches a steel center rotor with two aluminum sinks that maintain full contact with the steel in order to “suck the heat out of the braking surface,” according to Moore.

The spider rider prototype rotor:
Matt Pacocha/BikeRadar

The Spider Rider prototype rotor              

Heat management is a major contributor to overall braking performance and Moore also showed multiple prototype cooling add-ons for his brakes. The two fan-type devices increase airflow over the rotor – or directly blow air onto the caliper – for rapid cooling. The designs are currently prototypes, as Ashima have yet to hit their targets in regards to cooling.

Ashima’s prototype caliper fan:
Matt Pacocha/BikeRadar

Ashima’s prototype caliper fan