Gravel transmission

The single chainring for simplicity and serious gravel riding; the double for cyclists coming from road cycling or undertaking long routes. The single chainring (1x11 or 1x12) eliminates the front derailleur, simplifies gear management, reduces weight and eliminates chain derailment issues off-road. Ideal for bikepacking and mixed rides with a focus on trails. The double chainring (2x11 or 2x12) offers a tighter gear range (smaller gaps between gears) and higher gear ratios on the road, which is appreciated by cyclists who often ride at high speeds. Shimano GRX offers both configurations.

Both are excellent; the choice depends on personal preference and the existing setup. The SRAM XPLR is 100% wireless (AXS), with an XPLR derailleur optimised for large cassettes (10-44), and lever ergonomics that are appreciated when in the low handlebar position. The Shimano GRX Di2 is wired or semi-wireless depending on the generation, offering the Japanese brand’s renowned reliability and broad compatibility. SRAM appeals to cyclists seeking a fully wireless, cable-free drivetrain. Shimano attracts riders with its proven reliability and global service network. To start with, the two mechanical versions (GRX 600 and Apex XPLR) offer excellent value for money.

No, not directly; the XPLR and Eagle systems use different freehub bodies (XDR vs XD) and incompatible derailleurs. The SRAM XPLR uses a road-specific XDR freehub body and a 10-44 cassette with a dedicated XPLR derailleur. Eagle MTB cassettes use an XD body and Eagle derailleurs. Some cyclists build ‘mullet’ drivetrains (XPLR shifters + Eagle MTB derailleur) to combine the best of both systems, but this requires meticulous compatibility checks and is not officially supported by SRAM.

Electronic systems require less day-to-day maintenance but need battery management and software updates.A mechanical drivetrain requires: cable tension to be readjusted every 1,000–2,000 km, replacement of cables and housings every 2–3 years, and fine-tuning of the shifting after each drivetrain service. A Di2 or AXS drivetrain has no cables to adjust: the derailleurs self-calibrate. Maintenance is limited to cleaning the components, lubricating the chain and recharging the batteries. However, a flat battery in the middle of a ride will stop the derailleur, and app updates are required to fix bugs.

A 1:1 gear ratio (equal gear ratio on the climb) is the benchmark: with a 40-tooth chainring and a 40-tooth sprocket, the cyclist can tackle the steepest gradient by pedalling at 70 rpm. For gravel riding in the mountains, the lowest gear ratio is the key factor. With a 40-tooth single chainring and a 10-44 (XPLR) or 10-51 (GRX 12V) cassette, steep climbs are manageable. With a double chainring (46/30 + 11-34), the 30x34 offers a similar gear range but with better intermediate gears on the flat. For heavily loaded bikepacking, going even shorter (38-tooth chainring) makes sense.

Yes, it is the world’s first 13-speed mechanical groupset, lightweight, precise and with unique ergonomics.The Ekar (1x13, 9-42 cassette) is renowned for its lightness (carbon cranks and derailleur), its exceptional mechanical shifting precision, and its ergonomic levers specifically designed for the shape of a gravel rider’s hand. Its 13 gears offer very close spacing despite the wide cassette range. Drawbacks: proprietary freehub body (Campagnolo N3W), cassette only available in 9-42, less extensive service network than Shimano. Ideal for cyclists looking for a one-of-a-kind high-end mechanical groupset.

Yes, but with limitations off-road. The Shimano 105 or Ultegra road groupset works perfectly on a gravel bike ridden mainly on tarmac and hard-packed tracks. The limitations: no chain guide on the derailleur (risk of the chain coming off on rough terrain), gear ratios not optimised for steep gradients (maximum 11-34 cassette), shifters less suited to off-road handling. For competitive gravel riding on less technical routes, this is a viable option and often cheaper than buying a dedicated GRX groupset.

Mechanical for beginners and those wanting to master maintenance; electronic for regular cyclists or those who value precision shifting.Mechanical drivetrains (GRX 600, Apex XPLR, Rival XPLR) are 30–50% cheaper, repairable and adjustable anywhere in the world, even using cables bought from a hardware store. It is the obvious choice for self-sufficient bikepacking and trips far from specialist bike shops. Electronic systems (GRX Di2, Rival/Force/Red AXS) offer unrivalled shifting precision, minimal maintenance and derailleur synchronisation that is appreciated on rough terrain. For a first gravel bike, a mechanical drivetrain is recommended.

€500 to €800 for a mid-range mechanical drivetrain; €900 to €1,500 for a top-of-the-range mechanical drivetrain; €1,500 to €3,000 and above for electronic systems. At €500–€800 (Shimano GRX 600, SRAM Apex XPLR), you get a reliable, gravel-specific drivetrain with a clutch-equipped derailleur and suitable gear ratios. At €900–1,500 (GRX 810, Rival XPLR, Campagnolo Ekar), the materials become lighter and precision improves. Above €1,500 (GRX Di2, SRAM Force/Red XPLR AXS), you’re entering the realm of high-end electronics. For a first gravel bike, sticking to the €500–800 range is a very sensible choice: the difference in performance is imperceptible on trails.