Cascade Components North Fork Brake Calipers

At least conceptually, hydraulic disc brakes are pretty simple. At the most basic level, they’re just a way of taking a force applied by your hand (squeezing the brake lever), multiplying it by a combination of mechanical and hydraulic leverage, and using it to squeeze a rotor. If you want more braking power (assuming the same brake pads and friction — we’ll come back to that later) you need to increase the amount of mechanical advantage one way or another. And there are a handful of ways to do that:

(1) Make the rotor bigger. A bigger rotor has more leverage over the wheel, and therefore more power.

(2) Make the wheel smaller — it’s the same thing as #1, but in reverse. A smaller wheel has less leverage over the rotor, and therefore the brakes have more power. But if you’re trying to upgrade the brakes on your current bike this one isn’t the most practical option, for obvious reasons.

(3) Add mechanical leverage by changing the lever design. The higher the ratio of lever stroke (at your finger) to the movement of the master cylinder piston (the part that pushes fluid down the line), the more leverage, and therefore the more power you have.

(4) Add hydraulic leverage by making the caliper pistons bigger and/or the master cylinder piston smaller. This is the same principle as #3 — the bigger the ratio of caliper piston area to master cylinder area you have, the greater the hydraulic leverage you have, and therefore the greater the power. Pretty straightforward.

Now, that’s not to say that designing a brake is easy — the details matter, a lot. Brakes need to work for an immense number of cycles, at a huge range of temperatures, and so on. And then there are a million other details to worry about. For example, getting the pistons to retract evenly and consistently is a tricky exercise in nailing the bore and seal geometry to get just the right rollback, to say nothing of all the details that go into the lever end, too. And while it’s easy, in theory, to make a brake immensely powerful, anything you do to increase either the mechanical or hydraulic leverage — points (3) and (4) above — is also going to make the lever throw longer and probably also mushier, with a less defined bite point.

That is, at least if you don’t change anything else to compensate. Cascade decided that they could increase the power of the Code by simply making a replacement caliper with significantly bigger pistons, but then make the pistons retract a shorter distance to maintain a very similar lever feel. Imagine what has to happen to push the pistons from their retracted position to engaging the brake — the lever needs to push a volume of brake fluid through the line that’s great enough to displace the pistons far enough to close the gap between the brake pads and the rotor. Bigger pistons mean more fluid displacement, and therefore longer lever throw — unless you reduce the distance that they have to move to compensate. And that’s exactly what Cascade has done. It does mean that there’s a smidge less clearance between the pads and the rotor (referred to as piston rollback), but I haven’t had any real trouble getting the calipers aligned and rub-free. It just takes a little extra care as compared to a stock Code caliper, but it’s still totally straightforward.