Shimano’s 4th-tier Tiagra groupset doesn’t often get accolades for innovation, but continually evolves with solid trickle-down tech. Now, still 10-speed Tiagra gets a significant hydraulic disc brake overhaul thanks to a slimmer set of Dual Control levers and lower (dare I say gravel-ready) gearing that more aligns with how many of us actually ride road these days.
Shimano Tiagra 10-speed ergonomic R4720 disc brakes
While lacking in glamour, Tiagra offers much of the same shift performance as 105 at much lower price. And when bikemakers are looking to offer bikes that are actually affordable, Tiagra is often the entry-level pricepoint on otherwise high-end bikes. Part of that is because even though Tiagra doesn’t step up to 11 speeds, it offers looks (& performance) on par with 105 or even Ultegra in some instances.
Now a new set of slim Dual Control levers that are a direct evolution from Dura-Ace to Ultegra to 105, and now to Tiagra offer both better fit in riders’ hands and much improved aesthetics. Tiagra R4700 got an option for hydraulic disc brakes a few years back with a non-series 10sp set of RS405 levers, that used the much maligned, bulbous 105 hydro levers. While the ergonomics weren’t quite as bad as they looked, few riders were happy with the look of the giant levers. Now the point is moot as the new R4720 hydraulic disc brake, 10sp mechanical shift levers are almost indistinguishable from 105.
With the new levers also comes a second short reach version for small hands (R4725) that could also be well suited for more off-tarmac riding as they also include a bit more outward slant.
Tiagra also now adds its own series-branded flat mount brake calipers for a complete unified road disc brake groupset look. Inside the mechanics of the Dual Control levers are identical to 105 (yet with 10 speed indexing) promising a boost in shift performance for Tiagra, and the same excellent brake power & modulation as more expensive Shimano road disc groupsets.
Tiagra R4700 sub-compact gearing
Beyond new levers & brakes, Tiagra now adds a third 48/34T chainset option to the road compact (50/34) & semi-compact (52/36) options. While not easier on the lower end, the smaller combo should deliver more usable gearing for rougher or steeper riding, while also cutting down the number of front shifts in regular riding.
Tiagra-level disc brake hubs
In addition to standard groupset components, Tiagra now also gets its own level centerlock, 12mm thru-axle disc brake hubset. The e-thru Tiagra hubs use 12mm x 100/142mm spacing and are available in 28 or 32 hole drilling.
Tiagra continues to offer a good starting point for riders new to road riding and specifically road disc, and will continue to see broad OEM spec on affordable drop bar bikes. All of the new components will be available at retail in June 2019, complimenting the existing Tiagra 2×10 groupsets.
