Gabe’s Bike Shop | New Shimano GRX & 105 Mechanical Groups
Hey everyone, it’s New Groupset Day! Today, Shimano brings us two new groupsets for drop bar bikes—mechanical shifting and 12-speed GRX and 105.
Since the last Shimano road group launch, when Test Editor Dan Chabanov first looked at 105 Di2 here and then compared it to Sram Rival here, we've waited patiently for a new mechanical iteration of the value-packed platform. On the gravel side, since Shimano launched its first generation of GRX in 2019, gravel riding has evolved and expanded in new ways. New GRX aims to address the needs of today's gravel riders with new 1x and 2x options.
Shimano makes both premier mountain and road groupsets, so it makes sense for the brand’s technology to blend in the middle. GRX, its gravel-oriented groupset, does just that with ideas and parts borrowed from both sides. With 105, Shimano takes its tried and true "trickle-down" approach of updating its new mid-tier groupsets with features and ideas from previously released high-end groups.
Here are some highlights of each group.
GRX
Shimano offers GRX at two levels for the crank and shifter/brake levers. These are dubbed RX-820 for the higher-end products and a lower-priced RX-610 series. The derailleurs are the same level, RX-820 (for 2x drivetrains) and RX-822 (for 2x). Cassettes and chains are borrowed from Shimano’s existing mountain and road 12-speed selections.
1x Options
Levers: Shimano offers dropper-compatible (RX-820 level only) and brake-only (RX-820 & RX-610 levels) left-side levers. Right-side levers are 12-speed mechanical shifting (also used on the 2x system). Both level levers are only compatible with Shimano’s hydraulic brakes.
The 820 levers have a slightly revised shape (to mate better with flared bars), updated hoods with changed texture, and Shimano‘s Servo Wave braking. The 610 levers only receive the updated hoods.
Crank: 40T and 42T chainrings are offered on 170mm, 172.5mm, and 175mm at the RX-820 and RX-610 levels.
Rear Derailleurs: There are two new 1x-specific RDs. They differ only in cage length. RX-822-GS for 10-45T rear cassettes and RX-822-SGS that works with 10-51T.
MicroSpine: These 1x cassettes are the same as existing 12-speed XTR, XT, SLX, and Deore mountain bike offerings. To use these cassettes, your wheels need a MicroSpine standard freehub body. So, if you plan to use your existing gravel or road wheels, be sure the brand offers a MicroSpline freehub body.
2x Options
Levers: A 2x-compatible left-side lever compliments the same right-side 12-speed GRX lever shared with the 1x group.
Derailleurs: There is a 2x-specific rear derailleur compatible with 11-34T and 11-36T 12-speed cassettes. A GRX 12-speed front derailleur is also new.
Cassette: While the new 12-speed 1x GRX requires MicroSpine, 2x GRX uses existing HyperGlide-compatible 11-34T road 11-36T cassettes.
105
Historically, 105 was always a bit of the “People’s Groupset,” pairing high-end road racing performance with lower-priced (and heavier) materials and finish quality. It is a reliable platform with “trickle-down” technology. In 2022, 105 Di2 brought technology, reliability, and performance from Ultegra and Dura-Ace to a more price-conscious level, but it’s still was a costly upgrade over the previous 105 11-speed groups. So, ever since its launch, we’ve waited for a rumored mechanical counterpart to break cover. That 12-speed mechanical group finally arrives.
Ultimately, not much has changed or was added to the 105 mechanical lineup. It gets an extra cog in the back, a refreshed appearance, and hopefully keeps the reliable shifting that 105 is known for. Our hope is that 105 remains a dependable groupset for the people. This means we expect the same (if not better) reliability, robust, and efficient experience as its 11-speed predecessor. Stay tuned for a full review soon.
Weight & Prices
These weights and prices include crank, chainring, derailleur, cassette, levers, front & rear brakes, rotors, and chain (with options to run a dropper or 2x system where applicable).
GRX
1x: Dropper Option
w/ 10-45T: Weight: 2,888.5 grams (claimed), Price: $1,572
w/ 10-51T: 2,899g* (claimed), $1,572
(* This configuration weighed in at 2,838g on our shop scale)
1x: Brake Only
w/ 10-45T: 2,822.2g (claimed), $1,542
w/ 10-51T: 2,833.2g (claimed), $1,542
2x:
48/31T w/ 11-36T: 2,961.5 (claimed), $ 1584
105
Weight: 3,026 grams (claimed), Price: $1,005*
(*That’s 42g and $881 less than 105 Di2)
My Take on GRX
With the larger 10-51T cassette, GRX makes a dramatic increase in the gear range that is available to riders on 1x setups. Although Shimano is still one tooth short of Sram's Eagle 10-52T cassettes.
It's also worth keeping in mind that while Shimano borrows the geometry of the GRX derailer from its mountain bike line, it is not cross-compatible with Shimano's mountain bike trigger shifters because it uses Shimano's road cable pool.
I am considering switching groups on my personal bike soon. But I don't know if I’ll stay mechanical or go the Di2 route. If you have a preference, tell me why! Should I stay with 105 or go with GRX?
With all this information at your disposal, are you upgrading? Is right now the time to ditch your old 10- or 11-speed groups for 1x or 2x? Let me know in the comments. Or send me an email at BikeShop@Hearst.com.
Hey everyone! It's a new groupset day from Shimano and we’ve been presented with two new offerings in the form of GRX & 105 12 spd mechanical. Since the last launch, when Test Editor Dan Chabanov, reviewed the launch of Di2 105, we’ve been patiently waiting for the new mechanical iterations. The first generation of GRX launched back in 2019. Gravel-specific bikes have been able to spec both 1x & 2x options offering reliable equipment for a range of disciplines from road, cyclocross, and even to gravel.
With Shimano offering both Mountain and Road groupsets, it makes sense for the technology found on both ends of the spectrum to find its way to the middle in the form of GRX, or their gravel-specific offering. Learning through the pursuits for efficiency & speeds from the road and the ruggedness of mountain bikes rolls all that knowledge into gravel. Having introduced a range of Di2 products recently, it naturally makes sense for Shimano to offer those groupsets in Mechanical standards, to help bring the price point down for those not looking to invest heavily financially.
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