Ashima Hydro-Mech converter at Taipei Show

Converter for mechanical-to-hydraulic brake levers

Fully hydraulic systems such as those soon to come from SRAM and Shimano will be the way to go for disc-equipped road and cyclocross bikes. But, with countless mechanical brake levers on the market, converters will still find some appeal. Ashima previewed its new Hydro-Mech at the Taipei Cycle Show and, based on the appearance and technical specs, there's a lot to like.

The Hydro-Mech operates much like Hope's converter, with the brake cable pulling directly on the end of a piston that pushes fluid through a hose to the adjoining caliper. Ashima's version, however, uses a two-stage piston with a large, 13mm-diameter to bring the pads quickly to the rim before switching a smaller 9mm generates more power.

Paired with Ashima's PCB brake caliper, which uses an expanding bladder to push the pads against the rotor instead of conventional pistons and seals, the system should provide more generous pad clearance than typical setups. Moreover, this means the arrangement should be more tolerant than usual of rotors that aren't exactly in the same position when swapping between wheels – a critical feature for 'cross racers.

Other clever details include a steerer-based mounting system that can be angled up or down for +/- 6-degree stems. The mounting bracket also doubles as the cover for the fluid reservoir, which reduces the system's size and weight.

The hydro-mech uses a two-stage piston that offers unique benefits when paired to ashima's pcb caliper. since pad retraction is dictated by flexible bladders instead of traditional seal rollback, this allows for more pad clearance, quick pad contact, and good modulation:

The Hydro-Mech uses a two-stage piston

Ashima doesn't have a pricing estimate yet, nor exact weight figures, although the company claims the Hydro-Mech will be the "lightest on the market". Ashima will start testing prototypes this summer and a full consumer release is expected some time in 2014. 

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James Huang

Technical Editor, US
James started as a roadie in 1990 with his high school team but switched to dirt in 1994 and has enjoyed both ever since. Anything that comes through his hands is bound to be taken apart, and those hands still sometimes smell like fork oil even though he retired from shop life in 2007. He prefers manual over automatic, fizzy over still, and the right way over the easy way.
  • Discipline: Mountain, road, cyclocross
  • Preferred Terrain: Up in the Colorado high-country where the singletrack is still single, the dirt is still brown, and the aspens are in full bloom. Also, those perfect stretches of pavement where the road snakes across the mountainside like an artist's paintbrush.
  • Beer of Choice: Mexican Coke
  • Location: Boulder, Colorado, USA

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