Choosing a drivetrain means deciding how many speeds you need, what budget you can stretch, and whether you want a complete groupset or just a missing piece. The four options below cover projects from a full gravel build to a single trigger shifter, with listed prices spanning a wide range. That spread reflects very different purposes, so the right pick depends on what you already have on your bike and where you plan to ride.
Quick Take
Quick take: If you're starting a gravel build from scratch and want the widest gear range, the Campagnolo Ekar groupset is the complete route. For a mountain or hybrid refresh, the Shimano Altus kit bundles the essential components in one box. Road, cyclocross, and gravel riders should look at the Campagnolo Centaur build kit. And if you already ride SRAM Eagle and just need a precise trigger shifter, the GX Eagle shifter is the standalone option.
Price Comparison
Here is how the prices compare:
| Product | Listed Price | Price Bar |
|---|---|---|
| Campagnolo Ekar Groupset 1 x 13 Speed Gravel Bike 172.5 mm 40T 9-42 Cassette | USD 589.00 | |
| Shimano Altus, SunRace, KMC Z Drivetrain Kit Mountain 6 Groupset 11-36 9-speed | USD 89.97 | |
| Campagnolo Centaur Black 10-speed Road Bike Groupset 175mm 53/39 12-27 Build Kit | USD 350.96 | |
| SRAM GX Eagle 12 Speed Shifter and Discrete Clamp Lunar Mountain Bike - NEW OEM | USD 41.00 |
Decision Matrix
- Pick the Campagnolo Ekar if you need a complete gravel-ready groupset with very wide gearing.
- Pick the Campagnolo Centaur if you want a traditional road/cyclocross build with Campagnolo shifting.
- Pick the Shimano Altus kit if you're refreshing a mountain or hybrid drivetrain and want all the key parts together.
- Pick the SRAM GX Eagle shifter if you already have a SRAM Eagle drivetrain and just need a precise trigger control.
Closer Look at Each Option
Campagnolo Ekar Groupset
The Campagnolo Ekar groupset is the full 13-speed option here and one that is aimed squarely at gravel riding. It includes a 172.5 mm crankset with a 40T chainring and a 9-42 cassette, giving you a very wide range for steep climbs and fast descents. As a build kit from Italy, it comes complete except for the chain, so you'll need to add your preferred chain. The tradeoff is the price: this is the top of the range at $589. It's also a 13-speed system, so you'll need a compatible hub and shift components that match Campagnolo's standard. If you want one box to turn a bare frame into a gravel bike, this is the one.
Shimano Altus Drivetrain Kit
At $89.97, the Shimano Altus, SunRace, KMC Z drivetrain kit is the lower-priced complete package for 9-speed mountain and hybrid bikes. The set includes a rear derailleur, front derailleur, shifters, cassette, and chain, so it's a self-contained refresh for bikes that use a two-chainring front setup. The rear derailleur is a long-cage Altus RD-M2000, and the front derailleur is an Alivio FD-M3120 side-swing with an E-type mount. The compatibility list covers mountain, fat, downhill, dirt jumper, hardtail, freeride, and hybrid frames. The limitation is speed: you're capped at 9 speeds, which isn't the choice for someone chasing the tightest gear steps. Also, because the front derailleur is E-type, you need a frame with the matching mount.
Campagnolo Centaur Build Kit
The Campagnolo Centaur Black 10-speed build kit is the middle-priced option in this lineup. It's a road groupset with 175 mm cranks, 53/39 chainrings, and a 12-27 cassette. It's sold as used, with excellent plus condition and very minimal wear; there's plenty of life left in the chain, cassette, and chainrings. The front derailleur has a 34.9 mm clamp mount. This kit is a way to get Campagnolo shifting for a cyclocross, gravel, or road project without reaching the top price in this lineup. The main limitation is that it's still a used groupset, so you're not getting the same factory-fresh lifespan as a new kit. The 53/39 chainrings and 12-27 cassette also lean toward road gearing, so steep gravel climbs may feel limited.
SRAM GX Eagle Shifter
The SRAM GX Eagle 12-speed shifter is the least expensive item here, but it fills a specific need: upgrading or replacing a trigger shifter on a SRAM Eagle drivetrain. It's sold as new OEM and has never been mounted. The package includes the discrete clamp, bolt, ferrules, shift cable, and cable end, so you have everything needed to install it on a bike with SRAM Eagle components. The shifter offers five clicks per stroke to shift to an easier gear and one click per stroke to shift to a harder gear. The tradeoff is that it's not a groupset. Without the matching Eagle rear derailleur, cassette, and chain, it won't move the bike. It's also specifically for SRAM Eagle, so it won't work with other drivetrains.
Final Recommendation by Use Case
For a full gravel groupset with wide range and Campagnolo components, the Ekar is the choice when the budget allows. If you ride road or cyclocross and want a complete Campagnolo build without going to the top of the price range, the Centaur kit makes sense. For mountain and hybrid riders who want a whole drivetrain in one purchase, the Shimano Altus kit is the practical pick. And for SRAM Eagle riders who only need a new shifter, the GX Eagle delivers exactly that.
