With the introduction of Shimano’s latest hydraulic brake, trickle down tech is alive and well. Now offering their third hydraulic road brake system that is also dedicated to flat mount, Tiagra is the latest group to get the nod. That makes Ultegra level, 105, and Tiagra – even Sora has its own flat mount brake though in mechanical. Any bets on what the next addition will be?

All of this of course is good news for consumers looking for a road bike with disc brakes as it means more options and lower prices for future bikes…

ST-RS405-R_zz_zz_STD_S1_draft ST-RS405-L_zz_zz_STD_S1_draft

Technically, prices haven’t yet been set for the ST-RS405 shifter and BR-RS405 brakes, but given that they are Tiagra level pricing should be reasonable. Keeping that in mind, the shifters are mechanical and will operate Tiagra’s 10 speeds with their VIVID Index System. The ergonomics look similar to that of the 105 level brakes with a protruding knob  out front but otherwise fairly low profile. Lever reach will have 10mm of adjustment and the system continues use of Shimano’s funnel bleeding technique.

Along with the flat mount rotors, Tiagra brakes will include SM-RT81-S/SS Ice Tech rotors in 140 or 160mm. The whole system should be available in July 2016.



  1. Are the pads compatible through the line? Would nice to be able to have a cheaper option than the finned pads at around 19 quid a pop.

  2. Trickle down tech is always welcome. I really don’t like the looks of the levers on these and 105, but the price will most likely be reasonable.

  3. It’ll never be cheap enough for the bargain basement crowd (see @NASH above). Shimano could give these away with a $50 gift certificate and you’ll still get the short arms-long pockets guy exclaiming, “Why not $100?”

  4. Assuming the road and MTB stuff is compatible (I have no road disc so…) but I’ve been buying Alfine resin pads for XT’s which can be had at places like Chainreaction for $6 a set. No need for the fin pads if your just doing flat stuff. If you’re riding the mountains, I’d spend the extra bit for the extra cooling.

    • Road and mountain brake pads and rotors will be compatible but that’s about it. Road levers will not work with Shimano Dynasys mountain bike dérailleurs and the housing on the brakes is different.

  5. I’m thinking nice alternative to Sram 10 speed hydro. This would be neat on a Salsa Fargo with an XT 9 speed rear derailleur that works fine on 10 speed cassettes with a 10 speed shifter.

    • onrhodes, Tiagra 4700 has a different cable pull than the 4600 10 spd that worked with the 9 speed MTB RD. The Tiagra GS RD can run a 34T cog per spec, and potentially a 36 though.

  6. The new Tiagra is not compatible with any of the older road 10 speed stuff and therefore it’s not compatible with 9 speed MTB rear derailleurs. In fact, apparently the new Tiagra shifters work with 5800/6800 derailleurs.

    • Obviously none but the system is falling apart. If things don’t slow down there will not be a local bike shop. You shouldn’t be able to buy online for less than a store can buy at wholesale. Shimano is being really terrible with this. SRAM is bad too but not nearly half as bad. Your job could be lost from cheapening of it too. I’m sure you wouldn’t be happy if that happened

  7. This is great news, but it’s a little frustrating that there’s no Tiagra-level post-mount option for the brake calipers. It looks like those of us with post-mount frames will need the BR-RS785 to mate with these STI levers instead.

    How difficult would it be to create adapters to mount Flat Mount calipers onto post-mount frames?

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