The gravel is a cycling discipline that has been booming for a few years now, and component brands have adapted to this boom by launching specific products to meet the needs of its practitioners. In addition to handlebars, forks, or wheels, there are now specific drivetrain groups for gravel and cyclocross, with a series of special features, technologies, and developments to pedal efficiently on trails or dirt roads and thus get the most performance out of the bike. If you have a gravel bike or are thinking of switching to this discipline, here are the current groups that the main manufacturers have launched for gravel.
Is it better to have a group compatible with gravel or a specific group for gravel?
Before thoroughly examining the different options for specific drivetrains for gravel, it should be clarified that in the current market there are groups and drivetrain components compatible with the practice of gravel, but their design and technologies have been applied to other disciplines: road, cyclocross, or even mountain bike. This is the case of the innovative and advanced Rotor 13, or the Force and Rival ranges from SRAM. Since gravel is a cycling discipline that incorporates features and mechanical elements from others, there is still not a great variety of specific groups for this use. Currently, only two brands offer them: Shimano and Campagnolo.
Shimano GRX
Shimano launched its specific group for gravel GRX with 10, 11 speeds and a special Di2 version in 2019, consisting of cranksets, chainrings, rear and front derailleurs, shifters, brake calipers, and wheels. The rest of the components (chain, cassette, pedals, or brake disc) are not specific to the group itself, but are part of Shimano's Ultegra and 105 road groups or the Deore XT MTB group, with which they are fully compatible.
From the brake levers of the Shimano GRX group, a dropper seatpost can be operated.
Likewise, the specific components of the group inherit a good part of Shimano's shifting technologies for road and mountain bike, slightly adapting them for the practice of gravel. These are the features of each of these components:
Cranksets
They are available with double chainring options (2x11 and 2x10) or single chainring (only for 1x11). The arm is made of aluminum with Hollowtech II technology (inherited from MTB), whose forging is hollow to reduce weight while maintaining resistance and stiffness levels. On the other hand, the chainline is +2.5 mm to accommodate setups with wider tires. Available with 46-30t and 48-31t for double chainring and 40 and 42 teeth for single chainring.
Derailleurs
Other components specifically designed for this Shimano GRX group are the front and rear derailleurs. The former, designed for 2x10 and 2x11 setups, as well as a special version for Di2, offers smooth shifting thanks to its integrated cable tensioner, which is easy to adjust. It has also been adapted to the wider 2.5 mm chain line to accommodate wide tire setups. As for the rear, it stands out for the inclusion of the Shimano Shadow RD+ chain stabilizer with an integrated lever to turn it on or off. This technology is very useful for neutralizing frequent chain drops on rough terrain.
Levers
The GRX brake levers integrate the front and rear shifters. Their design features special ergonomics to adapt to gravel use and they have a textured finish to prevent your hand from slipping. Additionally, the pivot axis of the lever has been raised 18 mm higher to make operation even easier. Finally, you can operate a dropper post from them.
Conclusions of the Shimano GRX group
The best: It has gearing options for double chainring and for single chainring, with 10 and 11-speed cassettes. In addition, it features a special Di2 electronic shifting version. The worst: It does not have a specific cassette for this group.
Campagnolo Ekar
Recently launched on the market, the Campagnolo Ekar is the second 100% gravel group, created exclusively for this discipline. Its main feature is that it is only designed and manufactured in a 1x13 version, thus exploring this new gear option that only Rotor had previously done with its multidisciplinary Rotor 13 group. Another of its highlights is the exclusive design for the gravel discipline in all its components. From the cassette to the calipers and brake discs, including the derailleurs and levers, all have been specifically developed for this group.
The only drawback of the Campagnolo Ekar group for gravel is that it does not have a version with electronic shifting.
This way, you won’t have to purchase the cassette or brake disc from another Campagnolo road group to complete the setup as you do with Shimano. This is the Campagnolo Ekar group, component by component:
Cassette
One of the strong points of the Campagnolo Ekar is its 13-speed cassette, which can be chosen in 3 variants, depending on the type of gravel the cyclist practices most: Endurance 9-36t for rolling profiles, Gravel Race 9-42t for high performance, and Gravel Adventure 10-44t for climbing focus. It is made from two monoblocks of aluminum and steel that combine lightness and durability.
Derailleurs
They stand out for their elaborate construction, combining materials such as polyamide and carbon fiber for a lightweight structure, and stainless steel bolts for greater strength. The rear also features a Clutch Lock to make wheel removal easier.
Crankset
The use of carbon to save weight continues with the crankset, using unidirectional fibers as the material for the arm. They are available in four lengths (165 mm, 170 mm, 172.5 mm, and 175 mm) and the chainrings (made of 7075 aluminum) come in versions of 38, 40, 42, and 44 teeth.
Chain
The chain is another design element intended to withstand the large number of cog changes it will be subjected to. It is 0.25 mm narrower than a 12-speed chain (4.9 mm). On the other hand, it features high-strength C60 steel inner links with nickel and Teflon treatment that increases its durability.
Levers
They increase adaptation to the cyclist's hand thanks to their double-curve shape. As for the shifters, they are based on the one lever, one action principle, so that each one has a single function, for upshifting and downshifting cogs. In addition, they incorporate the brand's Ultra Shift technology, which allows you to shift up three cogs with a single press.
Brakes
The hydraulic disc brakes have a special caliper that increases the modulation range of braking compared to regular road brakes. The discs are specific to this group and are available in 140 mm and 160 mm diameters, as well as the pads, which are organic and highly wear-resistant.
Conclusions on the Campagnolo Ekar group
The best: the group has exclusive components for gravel, lightweight and durable. It does not inherit components from other groupsets. It features a 13-speed cassette. The worst: it can only be purchased with a mechanical shifter. There is no electronic version.
SRAM Force 1
As we have already mentioned, SRAM does not have a specific gravel group like Shimano or Campagnolo, but it does have versions of its road groups with elements adapted for this use. They are easily identified because SRAM adds a 1 to the generic name of each road group to indicate it is a variant adapted for gravel. There are three versions:
- SRAM Force 1 for high-end.
- SRAM Rival 1 for mid-range.
- SRAM Apex 1 for entry-level.
All of them have in common that they are single-chainring transmissions with 11 speeds, although the Apex 1 is compatible with 10-speed cassettes. The difference lies in the ergonomics of the shift levers, which is better achieved in the Force 1 than in the other two. Also, the shifting technology is more efficient in the Force 1. For this reason, we will focus more on the SRAM Force 1, which is the group that can best compete in the market with the Campagnolo Ekar and the most complete version of the Shimano GRX. Furthermore, the new SRAM Force eTap AXS electronic (and wireless) group also features cranks and chainrings whose gear ratios and tooth design are adapted for gravel and cyclocross bikes.
Cassette
There are two 11-speed cassette options compatible with the Force 1 group: the XG-1175 with a more climbing-oriented 10-42 range, or the more rolling and performance-focused PG-1130, with range options of 11-25t, 11-26t, 11-28t, 11-32t, 11-36t.
Rear Derailleur
The Force 1 rear derailleur has an exclusive design inherited from the mountain bike groups, with a cage lock, 12-tooth pulleys with a special anti-mud and anti-lateral chain displacement design, and Exact Actuation technology that guarantees quick and precise shifts.
Cranksets
The cranksets are one of the standout components of the group. The crank arms are made of carbon fiber to save weight, while the chainring, made of aluminum, incorporates X-Sync technology to prevent chain drops and jumps and a special design to quickly evacuate mud. They are available with 38t, 40t, 42t, 44t, 46t, 50t, 52t, 54t chainrings.
Levers
The Force 1 levers have a slightly double-curved shape so that the rider can operate them more efficiently. In the hydraulic disc brake version, the inner part has been designed in such a way that it is easy to access the brake fluid circuit for bleeding. On the other hand, the shifter design has been optimized to be both lighter and more ergonomic.
Brakes
The hydraulic disc brake set incorporates the specific Force caliper, which allows for powerful braking with minimal lever pressure.
Conclusions about the SRAM Force 1 group
The best: Its mechanical simplicity. In addition, it is possible to acquire low-cost alternatives of gravel (Rival 1 and Apex 1) The worst: It is a valid group for gravel, but it is not 100% designed for this discipline; rather, it is an adaptation of the road group.