Ashima PCB “Pancake” Disc Brake Review

Front caliper with trick ano-crossover tube; no piston in sight

Let me start this off with a confession: I’m horrible at homework. My internet research skills are second to none, but if my assignment is to do the research before writing a preview post like this one, I will inevitably drop the ball. So when I wrote up my first impressions on the Ashima PCB brakes I left out the defining feature of these bad boys: no pistons. That’s right, Ashima claims this is the “World’s First Pistonless Hydraulic Brake.” Then again, you would have already known that if you had read element22’s post here.

View of the rear caliper and rotor

Standing in for the pistons in this minimalist design is a diaphragm of “high temperature performance rubber” protected from heat buildup by a heat retardant engineered plastic shield. Thin, light stuff for sure. Note in the photo the speedy-looking red anodized crossover tube which distributes the juice (they say “external fluid transfer”) to both sides of the caliper while earning mad style points. Rotors also look good and are feathery: the front is claimed 112g while the rear is claimed 85g. My finely calibrated pharmaceutical-grade scale confirms those are pretty accurate weights.

The business-end view of what I’m calling The Flapjacks.

At your fingertips you’ll find alloy levers working pistons inside plastic bodies. More of that smooth-looking red anodization hits bolts and piston pivots. It takes an allen to adjust reach, so keep your multi-tool out while you’re setting up the cockpit. Red accents show up in the clamp and a plastic insert with a stylized “A” cutout adds to the dialed appearance.

So how do they work? The big shakedown came on my trip to Ray’s Indoor MTB Park in Milwaukee. After bedding the brakes in with a dozen full stops from medium speed I got to ripping it up on the XC circuit and the skills features at the park. I rode like a man possessed, owed in part to the fact that it was February and I hadn’t ridden any trails in months.

Without letting up for a solid 2.5 hours I railed on these brakes. No big, sustained downhills, mind you, but a great test of the gear anyway. I sensed no fade; the rubber diaphragm is great at quelling the vibes so no chatter either. The design leads to a softer, less abrupt feel at the lever and I think that leads to great modulation as well. These are not ON/OFF brakes, so you’ll have to get used to giving the right pull to lock up the rear if that’s what you want. For the average Joe on the trails I think it’s just right.

At $229 retail these are worth the price for anyone looking for light weight, style, innovation, and unique technology. You’ll certainly have something to talk about at the trailhead bull sessions as you bring out the Mr. Wizard facts about “engineered” this and “high temperature” that to impress your riding buddies. Or you can just smile and let them try and guess what’s going on in there.

Thanks to the folks at Ashima for providing the brakes for review.

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