This week, it’s all about brakes, with a new anti-pitch/anti-dive system and premium disc brake rotor design from SRAM.

Starting with the bigger story, their anti-pitch patent application shows a system that runs both levers’ hydraulic brake lines through the rear rotor, with the “front” lever actuating both brakes and the rear caliper moderating how much pressure the front caliper applies to the front rotor.

sram anti pitch hydraulic brake patent application drawing

The idea is simple: Prevent riders from going over the bar. The execution is anything but simple.

Well, actually, the concept behind it is pretty simple, but the spring-loaded rear caliper mount and three-hosed layout isn’t. Here’s how it works…

sram anti pitch hydraulic brake patent application drawing

The rear brake lever (aka “right” lever for most of the world) operates the rear brake like normal. The front brake (“left”) lever becomes a dual-use lever that operates both calipers simultaneously.

Pull it and it pushes fluid to the rear caliper first, actuating the rear brake. As the rear brake pads contact the rotor, that friction rotates the caliper forward slightly. This rotation opens a valve that allows fluid to move to the front brake caliper and actuate the front brake, too.

sram anti pitch hydraulic brake patent application drawing showing closeup of caliper design

Where the safety brake magic happens is when the rider grabs too much brake. Normally, if we tried to brake too hard with the front brake (like, in an emergency situation), the front wheel would lock up and the rear wheel would lift off the ground. Affectionally known as an endo, the rider would likely go over the handlebars and be hurt.

SRAM’s anti-pitch braking system eliminates this by preventing an endo.

How? By immediately cutting off brake force to the front wheel as soon as the rear wheel lifts off the ground. Because the rear caliper’s rotation (the rotation that would open up flow to the front and actuate the front wheel) is dependant on the rear caliper spinning forward, as soon as the rear wheel lifts off the ground the rear brake would stop it from spinning.

sram anti pitch hydraulic brake patent application drawing showing closeup of caliper design

Fig 17A shows the caliper during braking, pushing  the caliper against the pin (802) that opens the valve (316) to the front brake. Fig 18A is when not braking, or when the rear wheel lifts off, and the valve pushes itself closed.

As soon as it stops, the caliper pulls back, shutting off flow to the front brake and opening it up…thus reducing or eliminating front braking power.

And as soon as the front wheel isn’t braking, the rear would immediately drop back to the ground. In reality, it would happen so quickly that you’d barely get the rear tire off the ground…certainly not enough to launch yourself over the handlebars.

Uses for SRAM’s Anti-Pitch hydraulic brakes

Let’s be real…it’s a bit of a cumbersome design for a performance bike. And performance riders at even the most basic level are using front and rear braking as part of their bike handling. So it’s not likely to see use on our road, gravel and mountain bikes.

But for commuters? City bikes and e-bikes? Definitely.

sram anti pitch hydraulic brake patent application drawing showing closeup of caliper design

OK, so what about that spring? It appears to be pulling the caliper forward, into the “open” position such that fluid would flow to the front brake. Which seems counter intuitive, in that we’d want it to be closed so that when there’s no forward rotation of the caliper during braking, it would remain closed, right?

Well, the patent says the spring is there to “preferentially bias” the caliper towards the open position, but it’s not strong enough to actually pull it open. Buried somewhere in the patent is, I’m sure, an explanation for how the caliper resists that force but, honestly, it’s enough to know that it does. And that the design allows for other iterations of biasing springs (like at 614) in lieu of a big ugly coil on top of the caliper.

Presumably, pulling the rear brake (right hand) lever would only activate the rear brake like normal. So, you know, we can still do some sick skids.

SRAM one-piece, dual-layer brake rotor

sram one piece brake rotor with dual layers patent drawing

Currently, SRAM’s brake rotors come in two varieties…full one-piece steel Paceline rotors, and their lighter two-piece Centerline XR rotors with an alloy carrier and steel brake track.

Brake tracks are generally stainless steel because it has the best durability, but aluminum dissipates heat better. To get both materials into a rotor, SRAM has thus far relied on a two-piece design that uses an alloy center section (carrier) with a steel rotor pinned or riveted to it. Those offer great braking and heat management, but they’re heavier than the simple, all-steel one-piece design.

sram one piece brake rotor with dual layers patent drawing

Their proposed solution in this patent is to spray molten stainless steel onto an aluminum carrier, creating a one-piece design with all the heat management benefits of a two-piece design.

The process is supposedly quite advanced (and expensive), but yields a very lightweight rotor. SRAM’s patent application shows additional design features, like air scoops, to maximize airflow over the surface and shed heat even faster. Slots and grooves add more surface area, and should help keep the rotors clean and dry, too.

We’re guessing these could produce some of the lightest rotors around, but also probably some of the most expensive.

Patent research assistance provided by Wheelbased.com. Check them out for deeper dives on some of these patents and more.

31 comments

  1. tech9 on

    SRAM should not patent anything involving hydraulic brakes. They have had 10+yrs of their hydro brakes being just junky. If you can’t figure it out by now, just give up and leave brakes to Shimano.

    Reply
    • Seraph on

      SRAM’s newest generation of aftermarket brakes have been flawless for me. G2, Level, Code, and Red AXS have all yielded amazing performance with no failures. Yes their older OEM stuff had issues, but they continue to be transparent about their shortcomings and I have yet to have them deny a warranty on an OE lever, regardless of age.

      Reply
    • Jan Nowak on

      It’s getting tiring. My code rsc are more powerful than my hope v4 brakes. Great modulation. Every part of those brakes may be replaced or repaired (in contrast to shimano where you won’t be able to replace anything). Loud in wet. Yes. But when you do what they are designed to do and shred down, they deliver. No fading. Consistent lever. Amazing brakes.

      Reply
    • ttxxdd on

      junky brakes indeed. it’s embarrassing when they need to be warrantied straight from the new bike out of the box. maybe they have figured it out with this new design though.

      Reply
      • JoeC on

        I wouldn’t bet on that. SRAM brakes have always been crap compared to Shimano. Same with their inferior shifting and putrid crank and bottom bracket designs like GXP, etc…

        Reply
    • Tiny Tim on

      I have had nothing but good experiences out of my Codes and DB5’s before that each with 4 years in service in demanding terrain. They where bled once or twice a year and pads replaced when needed that’s it. The DB5’s where abused and used well beyond their expected use but never failed.

      Reply
    • John on

      I wouldn’t be in any hurry to be first in line for new SRAM hydraulic brake technology. I still remember when the CPSC forced them to recall all of their hydraulic dropbar brakes, which meant waiting several weeks for replacement mechanical brakes and then several more months waiting for the actual replacement hydraulic brakes; for brand new bikes that couldn’t be ridden, returned or even sold. When it comes to hydraulic brakes, l would let someone else beta test SRAM’s next clever idea.

      Reply
      • None Given on

        Weeks? What am I missing here…you seriously did not ride a bike due to a warranty? Heck, I get a post card just about every month about a recall for the airbags in one of my cars (it is a 2005)…I drive it frequently (and will never have the Tikata replaced as it is not worth my time).

        Reply
        • John on

          @None Given:

          Yes. This was a safety recall, not a “warranty” item.

          At the time the CSPC issued the recall there were already 95 documented incidents of brake failure in the USA alone.

          Reply
  2. grahamwallace on

    I have done a few 45 degree controlled descents where all of the braking is on the front wheel. Using the back brake would have immediately locked it as, even though I was hanging right off the back of the bike, there was very little body weight over the back wheel.

    In Danny MacAskill’s ‘The Slabs’ video, he descends a very steep section with the rear wheel completely off the ground so he is totally dependent on the front brake to keep his speed under control. I don’t know what brakes he was using but his his ability to accurately modulate the front brake through these critical moments was awesome.

    I hope that nobody tries to use this proposed braking system in similar circumstances.

    Reply
    • ZEE on

      I wouldn’t imagine these would be for any real road or mountain bike. Probably more for e-bikes/hybrids with less skilled riders where users panic brake and grab a fistful of lever.

      Reply
    • JoeC on

      For MacAskill’s Slabs descent he was running a Magura MT7 with a 220mm Magura MDR-P rotor up front and a 200mm rotor on the back.

      And you are correct, on much of the descent his rear wheel was airborne off the rock, and he was completely controlling his descent speed with his front brake. This design of SRAM’s is a clown idea that no serious roadie, gravel rider, DH, or MTB rider would ever use or want to use. Heck, I would not even want to use it for basic commuting.

      Reply
  3. Dude On A Bike on

    Bosch incorporated a linked or “paired” brake system on motorcycles for years as does Nissin and Brembo.

    This technology would be a nice feature for e bike and city riders to combat panic braking but that’s about all until it can be modified at a very light level.

    They also use IMU’s to control brake angle control but less of a need for slower speed bicycles.

    Reply
  4. Amanda P on

    If they work well (and are sensitive to any rear wheel ground force), I think they could be good for general cycling, including mountain biking.

    Racers and pros/experts would not use them. They can interfere with purposeful endos and exiting a manual with the front wheel brake only.

    Reply
  5. MJimnibeers@hotmail.com on

    Ugh, Shimano did this with rim brakes back in the day and it SUCKS to work on them. They don’t work and the type of bikes they put them on (cruisers and commuters) don’t go fast enough for anyone to get hurt anyway. Cool solutions for non-existent problems.

    Reply
  6. JoeC on

    @ John

    Yep, it wasn’t a warranty issue. It was a risk your life, head, and neck issue from dozens and dozens of documented brake failures.

    Reply
  7. peoplepower on

    No more stoppies! But seriously, this idea is DOA. No commuter or cruiser is going over the bars by grabbing too much brake. It actually takes some effort to go over the bars. The front end will just skid out sideways instead. This system won’t prevent that…

    Reply
  8. Optional on

    Sorry, SRAM, but this patent will be denied. Honda have been using linked brakes on their motorcycles for decades. Nice try though

    Reply
  9. Sunday on

    having ridden many styles of bikes and terrains, this makes very little sense to me after reading it. But brakes are a feeling thing, and I have not felt how this system works. I own a 2020 KTM 790 adventure R and it has traction control based on many things like lean angle and speed and settings, and it has similar braking features. IMO, even in a basic commute situation, it results in lack of feeling of the machine and I think that in some situations it is better to go over the bars than not be able to slow. What will a rookie commuter do when they hit the brakes but the bike doesn’t slow? They don’t have the skill to adjust body position to the rear when only that brake is activated. The two-wheel-life requires some level of skill.

    Reply
  10. typevertigo on

    I have to say – the dual layer “spray on” brake rotor tech is a pretty neat idea. Might be unobtanium for a good long while though.

    Reply

COMMENT HERE: (For best results, log in through Wordpress or your social media account. Anonymous/fake email comments may be unapproved or deleted. ALL first-time commenter's posts are held for moderation. Check our Comment Policy for full details.)

This site uses Akismet to reduce spam. Learn how your comment data is processed.