They say that good things are worth waiting for, and if that has any truth to it at all, the Hayes Prime disc brakes should be really good. Just over a year ago, Hayes first took the wraps off their newest disc brake design and unveiled the Hayes Prime. Here is the proof that the Primes actually exist, and despite the delay are sure to start appearing on bikes near you.

How do the Primes stack up on weight?

Find out after the break!

A lot of talk was generated due to their supposedly revolutionary Poppet Cam lever stroke adjustment, which serves to increase or decrease the amount of dead throw (how much travel there is in the lever throw before it starts moving the pads) in the lever even while you are riding. In the photos above, the left photo represents the setting with the least dead throw, while the right shows the setting for the most. Personally, I can’t see myself adjusting my brakes mid ride, but I do like the fact that the brake has multiple adjustments, and best of all, they actually work! Both the reach adjust and the Poppet Cam adjustments are tool free and extremely easy to use, even with gloves on, and the make a noticeable difference right away.

The top hat reach adjuster is a welcomed carryover from the Stroker line of brakes, as it makes dialing in your levers quick and easy and requires no tools. My last pair of Hayes happened to be the El Caminos, and after a few runs the reach adjuster would start backing out, which I don’t see as a possibility here. The top hat features some pretty heavy detents, but nothing that would make it hard to turn.

Inside the caliper, lurking just behind the brake pads, are some fairly massive 26mm pistons. Increasing the size of the piston should effectively increase power. You may have also noticed the lack of the standard Hayes bleed nipple, which in a move seemingly right out of Avid’s book, the nipple has been replaced with threaded fittings on both ends of the brake. The fitting allow the installation of new bleed fittings that based on what I have read about the new bleed procedure, should make bleeding easier and less messy. Hopefully we can get our hands on one of the new bleed kits to find out!

If you notice, the top of the caliper is wide open, which means Hayes has finally embraced the top loading disc pad design. Not only does this make changing pads easier as you don’t have to remove the wheel, but it also makes aligning the caliper on the rotor easier since you can see it better and it improves the brakes cooling, acting as a massive vent. A new disc brake design means a new brake pad, which is what you see in the photos above. According to Hayes the new pads are made of a different material which should mean less noise and better heat dissipation. Like many other top loading designs, the Prime uses a 2.5mm allen screw to hold the pads in place, but unlike other brake designs, the Prime does not rely on a tiny c-clip or spring clip to keep the pin from backing out. The pin comes pre-treated with blue LocTite which should keep it in place, which means you don’t have to worry about losing those tiny clips anymore!

Rotors also receive a major overhaul as they are now, clearly, a two piece floating design with the “Sweeping Fin” venting pattern. Not to be excluded here are the excellent Ti rotor bolts along with all of the rest of the hardware. It very well may be the nicest hardware I’ve seen included with a brake. Keep in mind that this is all for the Prime Pro, as the Prime Expert has stamped rotors and steel hardware.

Obviously, Ti hardware isn’t just for looks, so what does everything weigh? For starters, the rotor alone comes in at 113g on my Park Scale which definitely isn’t the lightest 6 inch rotor, but the stiffness and performance from the two piece design may be worth it (we’ll see). On the right we have the rotor along with 6 rotor bolts, which by process of some grade school arithmetic means the Ti rotor bolts weigh in at 10g per set.

When it comes to the weight of the brake system, the front brake weighs 283g with pads and no hardware, while the rear adds 25g (with the exception of the two caliper bolts I threw in for some reason).

With everything together (both brakes, pads, all hardware, two160  rotors, and one 160 rear adapter), the grand total comes to 862g. Clearly, this isn’t the lightest set of brakes that you will find, but that’s ok, they’re not supposed to be. When it comes to the Primes, they are more about power and control than light weight. However, I did weigh my bike before and after the installation, and my bike set up with full Shimano XT brakes was actually about 85 grams heavier, than when I had the Primes installed. Not bad.

All I can say at this point, is that if the Primes have the performance to back up their looks and performance, Hayes really has gotten it right.


  1. I understand the concept of deadthrow in the lever and why you might want it, just not sure I’d want it. I’m sure you would get used to it, but it still seems a little disconcerting. I mean I wouldn’t want deadthrow in the brake pedal of my car ya know? If I squeeze on the lever I want the pads move, plain and simple.

    But who knows. I can’t knock them until I’ve tried them.

  2. Every brake on a bike or car for that matter has dead throw, if it didn’t your brakes would constantly be dragging. Without dead throw the lever wouldn’t have any movement when you pull it. The Primes just feature a novel way to adjust the amount of dead throw, some people get better leverage with the lever engaging closer or farther from the bar.

  3. @dicky:

    Regarding your third question, all I had to do was merely *think* that I might be *interested* in these brakes, and, almost immediately, someone commented that I have a striking resemblance to a certain Mr. Clooney. Also, for some reason, people keep calling out to me, “Brad, marry me!” I also think that I’m being stalked by a women’s volley ball team. Weird.

  4. I think Hayes blew it when they didn’t make them a flip-flop design. I like to ride moto style, front brake on right hand. The hose fittings and bleed procedure better be easy or I’m going to Avids.

What do you think?