Over the past few years, I’ve noticed Shimano has consistently made major road bike product announcements in the couple weeks before and after April 1st.
In 2014, it was the then-new 105 5800 groupset, which marked its move to 11-speed, and the second-generation RS785 hydraulic disc brake system.
In 2015, it was the Tiagra 4700 groupset and the RS505 hydraulic disc brake system.
For 2018, Shimano released two things: the 105 R7000 groupset and the Ultegra RX-series rear derailleurs. Let’s take a closer look.
Hot on the heels of Shimano’s Dura-Ace R9100 and Ultegra R8000 groupsets, 105 R7000 adopts a lot of their technology in a trickle-down arrangement, while lowering prices and simplifying materials and construction. 105 is widely considered as the all-rounder groupset, serving both roles of robust, reliable componentry for amateur enthusiasts, and a frequent starting point for serious racers.
Perhaps the biggest news is that 105 gets its own hydraulic disc brakes. Previously, bikes fitted with 105 were paired with the RS505 hydraulic disc brake system, which is considered non-series componentry. As such, the RS505 STI levers never really looked like they belonged to the 105 groupset, and quite a number of people found them particularly hideous and ungainly.
The new dedicated ST-R7020 hydraulic-brake STI levers have a much more svelte shape, 95% identical to the cable-actuated ST-R7000 version. Fascinatingly, Shimano also included an ST-R7025 version for riders with smaller hands. These have 4 mm less reach to the brake lever and are bowed out slightly more than the regular levers. Personally, the ST-R7025 is much more interesting to me than the rest of the hydraulic parts, because the Flat-Mount brake calipers are essentially the same as what we’ve already seen since 2015, and the brake rotors are similarly recycled from mountain bikes.
Next in significance is the new RD-R7000 rear derailleur, available in both short-cage “SS” and medium-cage “GS” guises. Like with Dura-Ace and Ultegra, 105 borrows Shadow technology from the mountain bike world. This pulls the rear derailleur further inboard, introduces direct mounting to the frame…and gives the whole thing a more angular look. In the event of a crash, the rear derailleur is better protected from damage, and the revised motion and positioning of the derailleur cage improves rear shifting.
What Shimano doesn’t tell you is that Shadow rear derailleurs also sport stronger springs in their knuckles compared to the outgoing design. As Dany of the SickBiker YouTube channel has demonstrated, this quiet modification improves chain tensioning, reducing chain slap and the chance of chain drop.
Pairing with the new rear derailleur are the same 11-speed cassettes from before, with the exception of a new 11-30T option and a new 11-34T variant improving ultimate low-end gearing by two teeth. Technically, the CS-HG700-11 11-34T is a mountain bike cassette, so it will also fit older 10-speed freehub bodies. It is a cheaper version of the CS-HG800-11 unit made available with Ultegra R8000.
Up front, 105 gets the more angular chainrings and much fatter drive-side crank arm treatment that Dura-Ace R9100 and Ultegra R8000 introduced. They also share updated chainring spacing introduced to work around the geometry of disc brake bikes with short chainstays. No change to chainring combination options though – R7000 soldiers on with 50/34T, 52/36T, and 53/39T.
The new cranks are made to work in tandem with a not-so-new front derailleur (and this means that you can’t use the new crank with the old front derailleur). While the outgoing 105 5800 groupset started life with the FD-5800 and its long lever arm design, in 2017 Shimano quietly released an FD-5801 unit that did away with the long arm and matched the twisting activation of the Dura-Ace R9100 and Ultegra R8000 counterparts. This design improved clearance for wider rear tires, further reduced shift effort, and integrated a barrel adjuster for fine adjustment of cable tension. The FD-R7000 is largely the same as the FD-5801 unit, down to the compatibility with the new chainring spacing – it’s just renamed to match the rest of the groupset.
For rim brake fans, 105 R7000 brings the ability to smoosh a 28 mm tire into their calipers – both single-bolt and direct-mount.
Overall, I like what I’m seeing with 105 R7000. Highlights for me are the ST-R7025 levers for riders with smaller hands, and the RD-R7000 Shadow rear derailleur. The former is a push to expand the appeal of the groupset to a larger audience; the latter should mean better chain security. I do think that Shimano missed a few potential steps, such as offering a 48/32T or 46/30T crankset option for the growing gravel bike crowd.
A few days prior to the 105 R7000 announcement though came these: the Ultegra RX rear derailleurs. Shimano worked with the Trek-Segafredo pro cycling team to test these parts on the cobbled Classics races in Belgium; as of this writing we should yet see John Degenkolb sprinting on the cobblestones with an RD-RX805 bolted to his Trek Domane at Paris-Roubaix.
So what’s so special with these RX rear derailleurs? If normal Dura-Ace, Ultegra, and now 105 adopt Shadow technology, Ultegra RX is the first iteration of Shadow Plus tech on the road. In addition to the direct-mount lower profile body and stronger knuckle springs, Shadow Plus introduces a clutch mechanism to the chain-tensioning cage of the rear derailleur. With it on, it prevents and controls the rear derailleur cage against moving forward too quickly, while retaining normal movement to the rear. This further improves chain retention by applying an iron hand to chain tension.
The switch on the clutch is used to turn it off, for facilitating rear wheel changes. You’re supposed to keep the clutch on at all other times. However, the clutch does create additional chain drag and can rob you of a watt or two of power, so experimental folks might prefer to run it with the clutch off except on seriously bad conditions. Differentiating Ultegra RX from SRAM’s clutched rear derailleurs on its 1x groupsets (Apex 1, Rival 1, Force 1) is that Shimano’s is intended to be used with front shifting.
As a rider who’s had problems with frequent chain drop before, I really dig the Ultegra RX units. However, they’re around double the price of the new 105 RD-R7000s. Now that those come with the stronger springs of Shadow technology, they should improve chain retention considerably even without the RX clutch.
2 thoughts on “Fresh metal musings: Shimano 105 R7000 and Ultegra RX”
Hi, thanks for this article 😉
Do you know if it is possible to mix 105 r7000 shifter and ultegra r8000 rx derailleur ?
Thanks in advance
It should work. All 11-speed Shimano road bike shifters and derailleurs will work with each other with no problems.
It’s very likely the Ultegra RX derailleurs will work with a Tiagra 4700 rear shifter too. Unlike older 10-speed shifters, Tiagra 4700 is essentially an 11-speed shifter with the 11th click removed.