As hour four approached of a recent gravel fondo, with sleet pelting me, and my quads aching, I hit the last big dirt descent. The best of the very bad line choices were pocked, slick, and rocky. My hands bounced on and off the tops of the brake hoods repeatedly as my numb fingers struggled for purchase on the brakes. Right about then, I sure could’ve used one of Shimano’s five new gravel-specific drivetrain setups, which begin to hit stores this July.
More on the mix of what’s coming in a moment, but first to that specific use case, where Shimano is not only the first to offer gravel-focused shifting, but is also the first brand to fully address the challenges of braking and shifting while also riding terrain that, until gravel bikes blew up, was basically the reserve of mountain bikes.
And the first factor that matters most when you’re on the diciest terrain is being able to hold on tight, which is why Shimano’s new brake levers and hoods have been reshaped.
Yes, that’s a subtle story, but it’s pretty key to performance.
Consistent across the entire new spread of 1×11, 2×11 and 2×10 systems (which range in price from roughly current Ultegra down through 105 and Tiagra, depending on how you mix and match) is a redesigned hood that takes a lot of the meat out of a too-fat shape that was originally designed for pedaling smooth asphalt.
So Shimano’s new hoods are not only taller at the ends, to prevent your mitts from breaking grip during steep descents, they’re also textured, to allow you to keep your sweaty, wet, or cold palms glommed to them.
Shimano also scalloped as much material from the hood shoulders, narrowing the shape and allowing for an enhanced reach of your index fingers to the levers. All of which might get you closer to the same easy, single-finger braking you get with modern hydraulic disc brakes on a mountain bikes.
Just as important as grip, is being able to stop.
Levers, after all, are levers, meaning, like a pry bar, your hand has to apply force at one end to create the impetus required to actuate the brake. Traditional road levers have mostly pivoted more easily from the drops, not the hoods, but on a steep descent on a gravel bike you’re frequently braking from the hoods, trying to prevent endo’ing, keeping your ass as far back as possible. That means you get less power into braking. But if you can change the location of the pivot in that see-saw lever action, and move it up, it takes a lot less pressure to brake from the hoods, which is just what Shimano did, moving that pivot point .7 inches higher, for more stopping punch without needing as much input at the end of the lever arm.
Then again, if you really want that from the bar tops Shimano also took a surprising step, adding the option of mini-bar-top levers that allow braking from the flats of your drop bars—identical to the wrist position of your hands while you mountain bike. Old-school touring bikes used to offer bar-top levers, too—and they sucked. But that’s because they were cable-actuated and deeply compromised both by the weakness of those calipers and the challenges inherent in cantilever brake designs. These new bar-top mini-brakes should be far better simply because they’re tied to the same hydraulic shifter/brake system in the hoods—and because Shimano’s hydros have consistently offered the very best braking performance of any brand on the market.
Given that so many gravel bikes these days offer over-wide, flat purchase points at the bar tops, being able to brake from, arguably, the very best steering position (i.e., why mountain bikes have horizontal bars rather than drop bars) could prove a revelation. And certainly for bikepackers who want a “roadie” position but have to fight even harder to keep from toppling during gnarly descents, bar-top-actuated hydros are going to be a godsend.
Yeah, yeah, but about the drivetrain?
It’s a good question, and the answer is we’re not sure that this part matters quite as much to most buyers as to bikemakers. The reason is that the most significant details are a bit in the weeds.
If you already own a Shimano-equipped gravel rig with through-axles, the good news is that upgrading to this new drivetrain series will work fine. You can keep using the same 15mm-hubbed wheels you have, although it is cool that Shimano’s debuting a new, blue-collar priced ($420) wheelset with wider, 21.6mm rims and it’ll be offered in both 27.5/650b and 700c (i.e., “road”) sizes.
The “weedsie” part of the equation is that GRX moves the chain line out from the bike frame, the better to prevent the chain from cutting into the path of fatter tires, and, Shimano says, combines the more consistent shifting of their gravel-specific RX rear derailleur that debuted last year with a full set of 2×10/2×11/and 1×11 setups.
It gets more granular still when you dig into the options, which include electronic shifting Di2 at roughly Ultegra-level pricing, in both single and double front chainring options. The negative of the new system could be gearing range, depending on what you ride. While SRAM’s Eagle system runs ultra wide gear ranges, with singlespeed cranks down to 30t and a 12-speed, 10×50 cassette, in 1x configuration, the widest Shimano gearing is an 11-speed cassette at 11×42 with a 40-tooth front chainring. Sure, you can go with two rings up front to get a bailout gear, but that adds complexity. Eagle became a default for a lot of gravel-heads because ditching a front derailleur eliminates complexity, and dirt adds maintenance issues as it is. If you’ve embraced the grime, running “one-by” became a kind of mantra among the faithful.
Then again, it’s arguable that the bulk of rides don’t call for running the ultimate granny-ness of Eagle.
One bonus of going 1x with GRX is the lefthand shifter function is replaced by control for an integrated dropper post, which is a pretty sweet and smart idea that brings us full circle back to those smart levers and rewired brake hood design.
This design may also have lots of uptake among cyclocrossers, where control is key, and better braking wins races. If the added leverage of those new brakes means you can save energy and are less gripped, lots of racers and even not racers who prefer a more traditional CX cockpit are going to go for this new system.