Spectrum: For almost two years, the SRAM Eagle 12-speed drivetrain has conquered the market and put a lot of pressure on the 2-speed drivetrains on mountain bikes. Bikes over 2000 euros are becoming less and less common. Also on e-bikes you mainly see 2-speed circuits. The SRAM NX Eagle has been on the market since the beginning of September and is now also officially approved for e-bikes. Does it make sense to drive a 1-speed system? Especially about e-bikes? Velomotion explains.
SRAM Eagle 12-speed drivetrain in detail:
What can a 12-speed drivetrain do better than a 2-speed drivetrain or 1×11 groupset?
With 10 to 50 teeth, the SRAM Eagle creates a range of 500 percent, which corresponds to a 2×11 Shimano drivetrain with 26/36 cranks and 11-40 cassette. Anyone who has previously ridden a 1×11 circuit will clearly feel the increased bandwidth. Even with a four-tooth larger chainring, you still have an easier climbing gear and can also apply more pressure downhill. For example, if you have previously used a 1 chain ring with the Sram 11×32 group, you can now use a 1×12 with a 36 with the same or slightly lighter mountain gear ratio.
A calculation game for climbing:
Sram 1×11: 32:42 = 0,762
Sram 1×12: 36:50 = 0,72
With a cadence of 60 to 90 revolutions per minute, the new Eagle groupset (36 teeth and 27,5 inches) allows a speed range of 5,8 to 43,5 km/h. With the previous 11-speed cassette, the speed range with a 32-speed chainring is significantly narrower at 6,2 to 38,7 km/h under the same conditions.
Lighter than 2x
In addition, a 1×12 circuit is significantly lighter than a 2×11 circuit. Depending on the Eagle groupset, you save around 300 grams here.
How much does a 12-speed circuit cost?
From the recently introduced NX Eagle for 319 euros to the top model, the SRAM XX1 Eagle for 729 euros, the customer is spoiled for choice.
How many switching groups are there?
SRAM offers four different 12-speed Eagle groupsets.
Can the vector groups be mixed with each other?
Yes, the switching groups can be interchanged as desired. But beware! Only the NX Eagle cassette is approved for an e-bike. That means I could, for example, ride an NX Eagle cassette on my e-bike, an XX1 rear derailleur and an XO1 trigger. The chains from SRAM can also be mixed on any groupset. With a mountain bike without an electric drive, the cranks can also be mixed. This is not possible with e-bikes because of the different motors. Here you only have the SRAM EX1 crank to choose from.
For example:
Does the SRAM Eagle 12-speed drivetrain make sense on an e-bike?
To return to our actual question of whether 12-speed gears make sense on an e-bike, we are clearly positive. So far, SRAM cassettes have not yet been approved for e-bikes. In our opinion, the previously installed SRAM EX1 8-speed cassette had gear jumps that were too high for "non-racers", which meant that performance suffered. With the NX cassette, however, that has now changed and in the future you will find more and more 12-speed gears on e-bikes. This significantly improves the shifting performance on e-bikes as well. There is also a special trigger switch that features 1-click technology that significantly minimizes wear. Switching is absolutely impossible with the 1-click technology. In addition, the gear changes are gentler on the material than several jumps at once.
All of the NX Eagle's sprockets are made from steel and then riveted onto an aluminum spider to keep the weight within the frame. The cassette, weighing 615 grams, offers a gradation of 11-13-15-17-19-22-25-28-32-36-42-50 and was designed for the enormous forces exerted on e-bikes. Climbing aids ensure crisp, precise shifting.
The range when using the 11-50 cassette is at 454% slightly less than the 500% of the well-known 10-50 cassettes, but is still significantly higher than the 420% of an 11-speed drivetrain.
The SRAM E-MTB triggers at a glance:
Website