Not content with offering us a brand new Tiagra groupset yesterday, Shimano have followed that up with news that hydraulic braking is moving down to 105 level. There's entirely new callipers based on the Flat Mount standard, a new lever and new rotors. So new everything, really. And a new Ultegra calliper too, to make use of the Flat Mount standard.
The new ST-RS505 shifter (abover) looks a bit different to the current Ultegra-level one, the shape of the hood looks like it's been tweaked and stands a bit further proud of the lever (alloy rather than carbon presumably). The scheduled drop date for these products isn't until October, so what we're seeing here are renders rather than final products. It's an 11-speed shifter to match the rest of the 105 groupset. There's 10mm of reach adjustment so you can tune the levers to your hands.
The callipers (BR-RS505 for 105, BR-RS805 for Ultegra) utilise the Flat Mount standard that Shimano are pushing hard for road bikes. Callipers sit flush with the frame and fork so they're neater and more aerodynamic, and the whole assembly looks a bit more refined. "This new design allows consumers to move away from the mountain bike history and look, which has been used until now, using a method better suited to high performance road bike riding", say Shimano. The new callipers use the same hose routing as the newer Ultegra units, where the hose runs down the inside of the calliper for better heel (and mudguard and rack) clearance.
The new rotor, the SM-RT81, uses an alloy spider and Shimano's ICE technology construction: a layer of aluminium sandwiched between two steel outer layers. Both of these aid heat dissipation from the braking surface, although the new rotor misses out on the cooling fins of the more expensive SM-RT99 rotor that's currently available. So far as we can see from the press release it's only available in a 140mm diameter, but we'll check with Shimano. The new rotor should be available imminently.
There's no word on UK pricing yet, but with a set of the Ultegra-level 685 brakes currently £479.99 at RRP and £100 less than that online, we'd expect the new system to be somewhere around the £349 mark at RRP, for a full set of brakes (without rotors). When we know for sure, you will too.
Dave is a founding father of road.cc, having previously worked on Cycling Plus and What Mountain Bike magazines back in the day. He also writes about e-bikes for our sister publication ebiketips. He's won three mountain bike bog snorkelling World Championships, and races at the back of the third cats.