Superlight Ashima PCB Hydraulic Brakes – Unboxed and Weighed

Ashima’s pistonless PCB (PanCake Brakes) were announced last year, with anticipated U.S. delivery starting earlier this year. Well, J&B Importers says they’ll get their first batch and have them ready to ship to U.S. retailers in about three weeks. In the meantime, we’ve had our hands on two sets of early production test models. The first set didn’t work as planned (which I’ll get into in more detail when we post a full review…could have been damage-in-transit or just air in the system, we’re working with Ashima to determine, but it’d be premature to comment as to their quality), and our second set just arrived the other day and is being installed on the bike now to (hopefully) be raced this weekend at the BURN 24 Hour.

Update: U.S. MSRP will be about $200 / wheel.

The claimed weight for the set (front, post-mount, 160mm rotor) is 308g, and both of our test sets come in right around that number including all hardware, making them very light indeed. Performance remains to be seen, but click ‘more’ for photos, weights and some details…

FRONT BRAKE:

Above is the front brake from the first set we received, below is the second. At 202g and 198g respectively, they’re pretty darn light (and that’s with their little rubbery thing still stuck between the pads).

REAR BRAKE:

Above, the rear brake from the first set, below the second set. 214g and213g.

Note that the weight only increases about 12g to 15g with the additional hose length for the rear, and this is one concern we have with the Ashima PCB test samples we’ve received.

The rear brake hose length is only 134cm (52.75″), which is extremely short and within a hair of being too short to use. For comparison, a set of Shimano’s SLX stoppers has 166.5cm (66.5″) of hose for the rear, a full 22.5cm (13.75″) longer.

Here’s what that means when installing the brakes: You’ll need to run the rear brake cable on the right side of the steerer tube. Hopefully Ashima adds some length to the rear hose for full production models; it shouldn’t affect the weight much to do so, but it’ll make them much more useable. The bike above is a Large Trek Fuel 100 (circa 2003-ish), and I don’t think I could use these brakes as-is on any bigger bike…and they’d be hard pressed to fit a 29er or bikes with a long wheelbase.

Regarding the weight, the front hose length is 84cm (33″), compared to 97cm (38.1″) for SLX. Unless you’re running an extremely long travel fork (in which case you’d probably be running heavier duty brakes anyway), the length of the front hose isn’t an issue. But, for illustrative purposes, the additional 50cm from front to rear only added about 13g, so adding another 13″ of hose should only add a couple grams to the package, which is negligble.

Also, on the photo above, you may notice that the hose is mounted to the top of the master cylinder on the rear brake lever. That’s the first set they sent us, which was a UK (or moto) version with RIGHT-side front brake…which I mounted upside down (with Ashima’s blessing) so I could run them the way I’m used to…LEFT-side front. The new set we’re testing now is set up for LEFT-side front, per usual for the U.S., so the hose mount is on the bottom of the lever where it should be.

140mm rotor weight: 69g.

160mm rotor weight: 86g.

180mm rotor weight: 111g.

Rotor mount bolts: 12g / wheel (which puts a 160mm front, post-mount set at 198g + 86g + 12g = 296g).

So, technically, it comes in just under the claimed weight because there’s no way the two bolts that mount the caliper to the fork weigh 12g.

180mm rotor fork adapter: 7g of machined hotness:

OTHER PHOTOS:

The unique feature of the PCB brakes is the pistonless design. The brake pads are mounted directly to a diaphragm, which reduces moving parts and weight.

Brake fluid flows from one side to the other via the external red tube, which helps cool the fluid. Ashima says these brakes have excellent resistance to heat and fade, even on long downhills.

Top-loading pads are held in place via cotter pin.

We’ll post a full review after we’ve logged some miles on the set.