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Shimano announced today that several new road bike components were coming and of the crop listed this time, Tiagra 10 speed and the new road disc brake mounting standard are what grabbed our attention. Let’s start off with Tiagra and how things have changed from the previous version.
Tiagra has always been the “value” road group in Shimano’s road component line up coming in under the performance groups Dura Ace, Ultegra, and 105. You might recall that earlier version of Tiagra were sort of clunky looking with huge gear indicator windows and weird, knobby hood extensions. While these features have their fans, it placed Tiagra, which is actually a pretty decent working gruppo, in a spot where cyclists viewed the group as sub-par. Well, you can forget all about that now. Tiagra has benefited from the upper end groups in not only function, but in ergonomics and aesthetically as well.
Take for instance the cranks for Tiagra, which are offered in the same bolt pattern introduced on Dura Ace and used on the latest Ultegra and 105 groups, which is a four arm, offset bolt pattern that integrates the look of the chain rings into the crank. More importantly, it allows the outer ring to be three dimensional which greatly increases that rings stiffness and in turn increases front shifting efficiency. Interestingly, Tiagra is going to be offered in a triple configuration featuring a 50/39/30T set of rings. The double is a compact 50/34T set up, but we won’t at all be surprised to see 46/36 rings offered to match since this group will lend itself well to cyclo cross and that gearing is also popular with many gravel riders.
Speaking of gearing, this is where Tiagra gets interesting as a long cage derailleur is being offered which is compatible with Shimano’s new 11-34T 10 speed cassette in the Tiagra gruppo for 2015. Other cassettes available in Tiagra’s range include an 11-25, 11-28, and an 11-32 spread.
In terms of trickle down technology, Tiagra will also benefit from the longer lever arm on the front derailleur which has made shifting up front on Dura Ace, Ultegra, and 105 much faster and efficient. We expect similar results with this new Tiagra offering. The triple front derailleur is completely different, however, so the shifting performance of this component is not known at this time.
Brakes: In the brakes department, Shimano has expanded its offerings to 105 and Ultegra levels but what is really of interest is that Shimano has redefined how the calipers will mount to forks and frames by utilizing a new mounting type called “Flat Mount”. Shimano explains that it will be a ” clean, integrated look for road bikes“. It will be retrofittable to current IS type mounts vis a special adaptor which Shimano also introduced today.
The mount looks a lot like the old Hayes disc brake mount which appeared back in the late 90’s. The caliper on the new Flat Mount style mounts directly to the frame and fork with two bolts. The calipers feature the Ice Tech cooling fins that are a fixture of Shimano’s mountain bike brakes and the rotors are also replete with similar cooling features fine tuned for the road bike applications. Shimano tested and developed the calipers and pads specifically for this system and the pads are not compatible with the mountain bike hydraulic calipers.
Shimano also introduced a ST-RS505 11 speed mechanical shifter set compatible with the rest of the hydraulic ST-RS505 calipers/rotors that were introduced earlier.
The gravel/all-road bikes coming out in 2016 should be seeing spec with these components and we’ll be looking forward to checking them out when they do.
NOTE: Information and images used to develop this story were provided by Shimano.
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