Shimano Dura-Ace BR-RS9110 Direct Mount Rear Seat Stay Brake

Shimano Dura-Ace BR-RS9110 Direct Mount Rear Seat Stay Brake Info

If your bike has studs for direct-mount brakes, you’ve got a smart builder. Direct Mount brakes save weight, improve clearance, and, in some cases, improve aerodynamics. Shimano has three Dura-Ace 9100 versions, one for the fork, one for the seat stays, one for under the bottom bracket. They are BR-9110-F for the front (weight 155g), the BR-9110RS (152g) for the seat stays, and BR9110-R (133g) for under the bottom bracket. Each is sold individually.

They all work with the same dual-pivot concept that Dura-Ace debuted with the 9000 series and improved here. You might think that all they got was a new finish. They got much more. The pivots are in the same place, but the arms have been shaped and lengthened to better accommodate fatter tires. Shimano claims these brakes have room for 28mm tires, which means some even-larger tires should fit, though you won’t get a guarantee on that. They added a stabilizer between the pivots. This has multiple benefits. It stiffens up the arms, which in turn means less system flex and then helps with more predictable braking. In other words, modulation has been improved.

With the F and RS versions, shapes of the arms are sleeker, with less space between each arm. This might help with aerodynamics. But either way, the brake takes up less space and looks better, both good things.

Another small improvement to the F and RS that is both practical and potentially more aero is the micro-adjuster. When it’s in the “closed” position, it sits flush with the brake arm it sits at the end of. With this hidden in plain sight positioning, it will be hard for the little lever to get snagged or break on anything. There’s also a barrel-adjuster at the top of the cable-housing stop arm.

As always, there’s a centering bolt easily accessed from the top. Likewise, the brake pads. Shimano’s aluminum rim specific pad come standard. And just about every after-market brake pad is designed to fit in Shimano brake shoes. Remember to switch to a carbon rim-specific pad when riding wheels with carbon-fiber braking surfaces.

The Shimano Dura-Ace BR-9110 Direct Mount Brake uses specific frame mounts to provide lighter and stiffer braking, two efficiencies that nobody should ever turn down.