BIKER'S EDGE

Sram just released the Maven brakes — and they’re huge. They’re probably one size smaller than the brakes on your Ford 350 super duty. Maven is designed for “extreme-duty” offering more power and control. So let’s dive in and see what they’re all about.

Just a quick primer on Sram brakes before we get to the nitty gritty. Sram offers three levels of brakes, light-duty (Level), heavy-duty (Code) and now extreme-duty (Maven). So now let’s see what makes an extreme-duty brake.

Sram Maven: More Power

First of all, Mavens are huge. They’re roughly the size of Rhode Island. They have 4 big pistons in the caliper and a big lever piston to match. This can generate 50% more power than Code brakes. All the power in the world would do you no good if the caliper just exploded or warped under the fluid pressure. The Maven caliper is held together by 4 big bolts.

The pads on the Mavens are now dubbed XL. So they’re big. And they have a lot of contact with the rotor.All this power means there’s less force required at the lever. That means you won’t get so much arm pump with the Mavens.

Because Mavens are huge, they’re heavy. You’ll want to hit the gym a few times to have the upper body strength to get these installed on your bike. Weight Comparison vs codes

It’s getting hot in here

Science with Conor time. Let’s talk about racecars for a second – Formula 1 brakes run very hot. They wont even start to bite until the 400-600 Fahrenheit point. They can get even as hot as 1800 degrees. The first corner of an F1 race can be tricky, because the brakes aren’t up to temperature yet so they don’t have any bite. On the other hand, some tracks are tricky because they have lots of tight corners and short straightaways so the brakes aren’t able to cool down with air flow. It’s a precise game trying to keep brakes at the optimal temperature. The same can apply to mountain bikes, although at a far less extreme level.

Like the guy who wears a tiny beanie, Brakes need some heat, but not too much. Mavens have a greater thermal mass than most other brakes so they take a little longer to heat up, but they resist overheating better. Once up to temperature they can hold an optimal temperature better and avoid fluctuations in heat either from cold air outside or Jerry-skidding down the mountain. In other words, warm them up and they’re going to be nice and strong for the rest of your ride.

Mineral Oil?

Sram has typically used DOT fluid in their brakes. DOT fluid has a few advantages over mineral oil, but it also has a few cons. Let’s start by talking about boiling point.

Remember that Ted talk on heat? Brakes need incompressible fluid to push the pistons when you pull the lever. Water would get hot and simply boil inside your brake, turning into gas and making your brakes completely worthless (gas is compressible). When you squeeze the lever, the air inside the line compresses, and the pistons don’t move. 

Thats why brakes use DOT fluid or mineral oil. DOT fluid has a really high boiling point, typically higher than mineral oil. The DOT 5.1 that Sram uses boils at about 515 degrees. That’s when it’s clean and not contaminated by water. Once it’s contaminated, it boils at 375 degrees, which is coincidentally the perfect temperature for cooking pancakes. It takes about 2 years for DOT fluid to absorb 4% water. This water comes from the air you ride in — no seals are perfect and water will get in.

Mineral oil, on the other hand, can have a lower uncontaminated boiling point than DOT fluid, but unlike DOT fluid, it is oil, so it’s hydrophobic and repels water. So its boiling point stays consistent over time. The problem is, water will always enter the system. So now it just pools somewhere inside your brakes until you bleed them. Better seals like those found on the Mavens will help keep this water out. Sram has gone with mineral oil for the performance and maintenance benefits on the Mavens.

Tuning

In the past, I’ve cussed out internal cable routing, bolted brakes on, done a half-assed job at bedding the pads in, and hit the trails without too much thought. Now, with the Mavens, you have some tuning options to get the best performance. 

Let’s start with rotors. Sram recommends starting at the smallest rotor size your frame and fork will allow — crazy right?

Don’t just assume you’re super gnarly and need the biggest rotors. These brakes are different than most you’ve ridden. If your rotors are too big, they won’t heat up enough to work properly. Look at the rotor spokes to judge if you need a different size. Each 20mm increase in rotor size adds 14% power to the system.

---

---

You can further tune the Mavens with brake pad material.

 

So there you have the breakdown on the new Sram Mavens. I’ve mounted these up on my Yeti SB160 for some proper testing. Give us a bit of time, and pray for summer weather here in Utah, and we’ll get a full ride review out. See you next time.