Ashima “Piston-less” Hydraulic Disc Brakes

ashima-pancake-hydraulic-brakeCalled the PanCake, Ashima’s new hydraulic disc brake is the world’s first piston-less design for bicycles.

Featuring a direct line into a diaphram, it foregoes the typical piston design by placing the brake pad on a diaphragm seal that controls the movement. Said to have pad retraction of 0.7mm and an ultrathin caliper body of just 25mm. The seal design is equivalent to using a 20mm piston, and the fluid flows directly to the center of the diaphragm. Ashima claims this provides a better feel and pad response, and the thinner caliper body reduces overall weight (none listed on their site, though).

Click image to enlarge.

On the other side of the spectrum, they’ve also released a 4-piston beast that uses a dual-stage push…very cool, very unique and very much pictured after the break…


Called the APV (Ashima Power Valve System), it has four total pistons comprised of two pair of axially mounted pistons.

Designed to have very light hand feel, initial braking force uses 14mm pistons for light control. Grab more lever and it releases two 22mm pistons to really clamp down on the rotors. This results in better modulation with less force required on the lever. it has external fluid transfer, which aids in cooling (we’re guessing that’s what that little red “pipe” is on the outside) and air-cooled pistons.

Both models should be hitting the UK this year through Zyro, but the items aren’t shown on their site yet for pricing.


[…] queue.  Dubbed the PanCake Brake (PCB), it uses the same PanCake design of their forthcoming pistonless mountain bike disc brakes.  The hydraulic line feeds directly to a diaphragm seal that holds the pad, eliminating the […]

[…] pistonless PCB (PanCake Brakes) were announced last year, with anticipated U.S. delivery starting earlier this year.  Well, J&B Importers says […]

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