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Sram RED AXS 2024 in Review

Sram RED AXS 2024 in Review

07.01.25 08:27 2Text: NoPain (translated by AI)Photos: Erwin HaidenLong-term test of the revised Sram RED AXS: with optimized shifting performance, reduced weight, greater gear range, more powerful brakes, and a reliable power meter.07.01.25 08:27 246

Sram RED AXS 2024 in Review

07.01.25 08:27 246 NoPain (translated by AI) Erwin Haiden
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Long-term test of the revised Sram RED AXS: with optimized shifting performance, reduced weight, greater gear range, more powerful brakes, and a reliable power meter.07.01.25 08:27 246

History of the electronic Sram RED (eTap -> AXS)

Since the presentation of their first road bike groups in 2006 - the Force and Rival - Sram has regularly caused a stir in the market. While Shimano works with a more conservative and methodical approach and Campagnolo largely remains technologically loyal to its followers, the American company takes a different path: continuously driving innovations and repeatedly breaking new ground.

With the introduction of the RED eTap (2015), Sram marked a paradigm shift in the cycling industry: moving away from mechanical and wired systems, towards electronic, wireless, and customizable shifting.
This group was groundbreaking, as it completely eliminated wires between the shift levers and derailleurs, unlike the competition (Shimano Di2 and Campagnolo EPS). Additional advantages included the simple operation - the right shift lever shifts to a harder gear, the left to an easier gear, and both together switch the chainring - as well as the interchangeable batteries directly on the derailleurs.

In 2017, Sram combined the wireless shifting with hydraulic disc brakes (Hydraulic Road Disc, HRD) through the RED eTap HRD and went a step further in 2019 with the market launch of the AXS platform and the RED eTap AXS: integrating an app for user customization, maintenance alerts, and firmware updates, as well as the use of 12-speed cassettes for a wider range and closer gear steps.

Although the RED eTap AXS has since been among the top shifting groups in the road and gravel bike sectors, it faced criticism for its limited chainring selection (X-Range), often imprecise front derailleur function, its rather clunky lever ergonomics, and braking performance that was only mediocre for a premium group.

However, that changed last year when Sram made perhaps the most remarkable step in the evolution of their high-end shifting group with the launch of the RED AXS.

  • Sram RED AXS 2024 in Review

SramRED AXS 2024

The latest generation of the Sram RED AXS road bike groupset remains wireless and equipped with twelve sprockets on the cassette, but has been completely redesigned in all other aspects compared to its predecessor, saving an impressive 154 grams in weight – the term “eTap” has also been removed from the product name.
The innovations range from improved shifting performance at the front derailleur to optimized shift and brake levers. Additionally, new cassettes and a derailleur with greater range have been introduced, and braking performance has also seen a significant improvement.

From summer to winter, we were able to form our own opinion of the new Sram RED AXS during a long-term test on our Trek Madone SLR 9.

 Shift and brake better with less weight. 

Sram RED AXS 2024
  • Sram RED AXS 2024 in ReviewSram RED AXS 2024 in Review
  • Sram RED AXS 2024 in ReviewSram RED AXS 2024 in Review
  • Sram RED AXS 2024 in ReviewSram RED AXS 2024 in Review
  • Sram RED AXS 2024 in Review
  • Sram RED AXS 2024 in ReviewSram RED AXS 2024 in Review
  • Sram RED AXS 2024 in ReviewSram RED AXS 2024 in Review
  • Sram RED AXS 2024 in ReviewSram RED AXS 2024 in Review
  • Sram RED AXS 2024 in ReviewSram RED AXS 2024 in Review

Weights: Sram RED AXS in comparison

Weight is not everything, but less weight is always an advantage with increased performance – especially in the road bike sector, where every gram saved counts. A lighter groupset not only reduces the overall weight of the bike but also improves acceleration and creates a more agile ride.

That’s why weight reduction was at the top of the priority list during the development of the new Sram RED AXS. The result is impressive: the new design is a full 154 grams lighter than its predecessor. Compared to the Force AXS, it has even expanded its weight advantage by a significant 376 grams. Even in comparison to a similarly configured Shimano Dura-Ace Di2 component group, the two are separated by only a few grams – depending on the gearing.

RED New vs. RED Old

Sram RED AXS Sram RED eTap AXS Weight Savings
Cassette 10-28 180 g 181 g 1 g
Bottom Bracket DUB BSA 76 g 76 g 0 g
Crankset 172.5 mm / 48-35 545 g 574 g 29 g
Crankset 172.5 mm / 48-35
with Powermeter
580 g 609 g 29 g
Rear Derailleur (without battery) 262 g (36T Max) 278 g (33T Max) 16 g
Front Derailleur (without battery) 145 g 149 g 4 g
Shift-Brake System 689 g 772 g 83 g
Chain (114 links) 236 g 249 g 13 g
Brake Rotors (2 pcs. á 160 mm,
including lockring)
280 g 288 g 8 g
2 Batteries 48 g 48 g 0 g
Total 2,461 g 2,615 g 154 g
Total with Powermeter 2,496 g 2,615 g 154 g


Since researching the individual weight specifications is very labor-intensive, we honestly pulled this table from the internet. However, we are confident that the data is accurate because the 154-gram difference matches Sram's specifications exactly.

  • Sram RED AXS 2024 in Review

The test bike

The platform for our Sram RED AXS test group was the Trek Madone Gen 8, an evolution of the popular aero road bike that offers numerous improvements compared to the Gen 7: The frame made from the latest OCLV carbon is lighter without compromising aerodynamics or stiffness, while the IsoFlow system enhances comfort compared to the aero predecessor and absorbs road irregularities more effectively than the Émonda.

Madone SLR 9 AXS

Frame 900 Series OCLV Carbon, Full System Foil tube shaping, IsoFlow seat tube, RCS Headset System, electronic-only routing, removable aero chainkeeper, T47 BB, flat mount disc, UDH, 142x12 mm thru axle Fork** Madone Gen 8 full carbon, tapered carbon steerer, internal brake routing, flat mount disc, 12x100 mm chamfered thru axle
Sizes XS, S, M, ML, L, XL Cassette Sram RED XG-1290 E1, 10-33, 12 speed
Crankset Sram RED AXS E1, power meter, 48/35, DUB Chain Sram RED E1,12 speed
Handlebar Tape Bontrager Brake Sram RED
Handlebar/Stem Trek Aero RSL Road integrated bar/stem, OCLV Carbon, Race Fit, 80 mm reach, 124 mm drop Brake Rotors Sram CL, 160/160 mm
Seatpost Madone aero carbon seatpost, 0 mm offset, short length Bottom Bracket Sram DUB, T47 threaded, internal bearing
Saddle Aeolus RSL, carbon rails, 155 mm width Wheels Bontrager Aeolus RSL 51, OCLV Carbon, Tubeless Ready, 51 mm rim depth
Rear Derailleur Sram RED AXS E1, 36T Tires Pirelli P Zero Race, 120 tpi, tubeless compatible, 700x28 mm
Front Derailleur Sram RED AXS E1, braze-on Shift/Brake Levers Sram RED AXS E1

Optical drawback. Possibly favored by the slim aero handlebar-stem unit and the thin Trek handlebar tape, but also observed on other bikes, is the large gap between the SRAM RED AXS rubber hoods on the inner sides of the shift/brake levers and the handlebar (or handlebar tape). While this does not affect ergonomics, it looks a bit odd.

  • Unsightly finish of the grip rubbers...Unsightly finish of the grip rubbers...
    Unsightly finish of the grip rubbers...
    Unsightly finish of the grip rubbers...
  • ... or practical storage space for an emergency ciggie?... or practical storage space for an emergency ciggie?
    ... or practical storage space for an emergency ciggie?
    ... or practical storage space for an emergency ciggie?

 Less weight, more speed, and more comfort. 

Applies to both the bike and the group.
  • Sram RED AXS 2024 in Review
  • Sram RED AXS 2024 in Review

Lever design and ergonomics

Detailansicht

With the old RED eTap AXS, there was always the risk of pinching your fingers between the brake levers and the handlebar during hard and long braking maneuvers - depending on finger width or reach adjustment - or not achieving a full lever stroke, which could noticeably impair braking power.

With the new grip design, the longer lever body, and the slimmer shift paddles, this problem has now been resolved. The narrow grip rubbers not only feel ergonomic in the hand but also integrate more harmoniously into the top handlebar compared to the previous version.

  • Sram RED AXS 2024 in ReviewSram RED AXS 2024 in Review
  • Sram RED AXS 2024 in ReviewSram RED AXS 2024 in Review
  • Sram RED AXS 2024 in ReviewSram RED AXS 2024 in Review
  • Sram RED AXS 2024 in ReviewSram RED AXS 2024 in Review
  • Sram RED AXS 2024 in ReviewSram RED AXS 2024 in Review

Brakes

Thanks to the extended lever body, the brake master cylinder was shifted from a short, vertical position to a longer, horizontal position. This optimized the pivot point and increased the piston stroke.
The longer the stroke, the more power and control can be achieved. Sram states that the effort required on the brake levers has been reduced by 80% and by 33% in the drop handlebar grip. The completely independent adjustment of reach and bite point also allows for customization to personal preferences.

Detailansicht

The higher braking performance is said to be due to the revised construction of the polished brake calipers and the rotors positioned further outward, which at the same time enables more efficient heat dissipation.

Improvements to the pad guides and the brake surface geometry reduce vibrations and ensure excellent pad clearance, so that even on longer descents there is neither residual friction nor scraping noises on the rotors.

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  • Sram RED AXS 2024 in ReviewSram RED AXS 2024 in Review
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  • Sram RED AXS 2024 in ReviewSram RED AXS 2024 in Review
  • Sram RED AXS 2024 in ReviewSram RED AXS 2024 in Review

Shifting

Detailansicht

The shift logic has not changed. As before, you move the chain to the next smaller sprocket with the right button and to the next larger sprocket on the cassette with the left button. Pressing both buttons simultaneously activates the front derailleur, and holding down a button allows you to shift multiple gears at once.
Compared to the old RED eTap AXS, the shift paddles are slightly thinner and longer and seamlessly merge into the brake lever. This makes them easy to operate even with thick gloves, and accidental activation while braking is effectively prevented.

New are the bonus buttons on the inside of the hoods, which by default have the same function as the shift buttons on the brake levers. However, using the Sram AXS app, both buttons can be freely configured. They can take over any shifting function or even be used to control the bike computer.

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  • Sram RED AXS 2024 in ReviewSram RED AXS 2024 in Review
  • Sram RED AXS 2024 in ReviewSram RED AXS 2024 in Review
  • Sram RED AXS 2024 in ReviewSram RED AXS 2024 in Review
  • Sram RED AXS 2024 in Review

Rear derailleur and front derailleur

Detailansicht

While our experiences with the ergonomics of the grips and the shifting logic are rather subjective, the implementation of the shifting commands by the derailleurs can be evaluated much more objectively in terms of precision and speed. The conclusion: Both derailleurs operate precisely and almost as quickly as we know from the current Shimano Dura-Ace.

With the rear derailleur, this was not very surprising, as the predecessor already functioned reliably and only received minor, mostly superficial upgrades. These include a newly designed parallelogram and a new lower pulley, which now supports cassettes with a maximum of 36 teeth.

It is worth noting critically that the new rear derailleur is no longer compatible with the previous 10-26 cassette and still does not feature Sram's UDH standard, which was omitted in favor of weight savings. However, these limitations do not in any way diminish the overall good functionality.

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  • Sram RED AXS 2024 in ReviewSram RED AXS 2024 in Review
  • Sram RED AXS 2024 in ReviewSram RED AXS 2024 in Review
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  • Sram RED AXS 2024 in ReviewSram RED AXS 2024 in Review
Detailansicht

Sram has made a big step forward with the front derailleur. A slimmer derailleur cage speeds up the chain's transition from one chainring to another, and the new auto-trim function ensures that the thinner cage provides noise-free operation even with an extremely angled chainline.
The result: Front shifting has not only become faster but also significantly more precise. With the RED AXS, Sram has definitely closed the gap to Shimano Dura-Ace Di2, making the choice between the two rivals more a matter of personal preference.

As for the Sram AXS batteries, they continue to offer both advantages and disadvantages. They are easily accessible, simple to charge, and with an extra battery in your pack, you have a level of security that other electronic groupsets don’t provide. However, the batteries often don’t last as long as the manufacturer claims, so regular monitoring is advisable. A quick status check before each ride, however, is no big deal and can easily be integrated into your routine.

  • Sram RED AXS 2024 in Review

Gear ratios

Sram has clearly recognized that the previous RED cassette and chainring ranges were not optimally chosen and has addressed these shortcomings in the current version. From now on, the chainrings are offered in six practical combinations: 46/33, 48/35, 50/37, 52/39, 54/41, and 56/43 (with Sram stating that 48/35 is by far the most popular).
Additionally, there are four matching cassette options to choose from: 10-30t and 10-36t complement the already available 10-28t and 10-33t (the 10-26 variant has been discontinued, as described above).

A major advantage in terms of user-friendliness for retrofitting changes: Both revised derailleurs can cover the entire range. This means there are no different versions of the rear derailleur with short or long cage or chainring size restrictions on the front derailleur.

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  • Sram RED AXS 2024 in ReviewSram RED AXS 2024 in ReviewSram RED AXS 2024 in Review

 The ideal 2x12 gearing for everyone and every purpose. 

Factory-installed and also retrofittable without significant costs.
  • Sram RED AXS 2024 in Review

Optional: Power meter from the factory

The trend of modern groupsets is increasingly moving towards the factory integration of power meters, so the RED AXS is also very often offered with a power meter on complete bikes. This was also the case with our test bike, which was equipped with the AXS Quarq spider, still firmly integrated into the one-piece machined chainrings.
Critics might argue that when the chainrings wear out, a new power meter would be necessary, but in practice, this is extremely rare. It’s a different story when it comes to subsequent changes to the gear ratio, which is why this aspect deserves special attention.

However, there is no criticism regarding the functionality and accuracy of the power meter. Pairing was seamless, the power meter automatically zeroed itself during the ride, and the power readings as well as the left/right balance were always precise and plausible, as was the cadence calculation.
Battery replacement, if necessary, is also simple. When it comes to power measurement, Sram is clearly ahead of Shimano.

  • Sram RED AXS 2024 in Review

In practice

Long-term experiences with the predecessor group: We had the "pleasure" of testing SRAM's RED eTap AXS with 2x12 and powermeter for a long time on the Scott Addict Gravel. The group fundamentally worked well in pure road bike use, but consistently showed weaknesses compared to the Dura-Ace Di2, particularly with the front derailleur and braking performance. Shifting through the gears at the rear, on the other hand, worked excellently, although a slight delay between the actuation of the shift lever and the actual shifting process was always noticeable—not nearly as severe as with the first eTap versions, but still perceptible.
We found the somewhat clunky operation of the SRAM front derailleur less convincing, as it repeatedly caused shifting problems or even chain drops. Only after intensive, repeated fine-tuning of the front derailleur settings did the function improve, but it never quite matched the performance of a Shimano.

Accordingly, we were curious about the new RED AXS. And to be honest, its performance has very positively surprised us.

  • Sram RED AXS 2024 in ReviewSram RED AXS 2024 in Review
  • Sram RED AXS 2024 in ReviewSram RED AXS 2024 in Review
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  • Sram RED AXS 2024 in ReviewSram RED AXS 2024 in Review
  • Sram RED AXS 2024 in ReviewSram RED AXS 2024 in Review

Top: Ergonomics of the grips, functionality of the shift paddles, and bonus buttons
The new grips feel great in the hand, almost as good as those of the Shimano Dura-Ace Di2 9200. They are less bulky, ergonomically shaped, very grippy, and all controls are perfectly accessible. Cruising, climbing, descending – even on uneven terrain, the road bike can be safely steered. Shifting works excellently with both the shift paddles and the bonus buttons, and braking is a joy even with hands lightly resting on the levers, without pinching your fingers – whether with or without gloves.

However, considering the 6 mm longer lever body, you might want to rethink the length of the stem or consider a handlebar with a shorter reach. This applies both when interpreting frame geometry specifications of complete bikes and when doing a custom build. Compared to the old RED eTap AXS, you now grip the brake levers 6 mm further forward, resulting in a slightly more stretched riding position.

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  • Sram RED AXS 2024 in ReviewSram RED AXS 2024 in ReviewSram RED AXS 2024 in Review

Top: Braking performance and modulation
When it comes to braking performance, not only has the shape of the carbon levers been noticeably improved, but the significantly shorter lever travel with its precise pressure point is also fun.
The reason for this is said to be the higher positioned lever pivots, the stiffer brake calipers, and the optimally fitting brake pads, which together ensure low hand forces and progressively engaging, easily controllable braking power.

One-finger braking at 70 km/h downhill? No problem. Bringing the bike to a standstill confidently in any situation with the hands on the hoods? Easy!
What's more: The braking performance is so impressive that NoPain nearly flew off the road during the first sharp downhill braking at high speed - which was only prevented by the grippy Pirelli P Zero Race tires.

  • Sram RED AXS 2024 in ReviewSram RED AXS 2024 in Review
  • Sram RED AXS 2024 in ReviewSram RED AXS 2024 in Review

Top: Shifting performance, gear range, and power meter
The Sram RED AXS is the first 2x drivetrain from the American brand that is virtually beyond reproach. While its reaction speed is still minimally slower compared to the wired Dura-Ace, the AXS shift paddles score points with their more intuitive shifting logic, tactile handling, and crisp feedback—even with thick gloves.
There’s also nothing to criticize about the front derailleur under load. It impresses with the new auto-trim function and also allows for extremely angled chainlines. This means that regardless of whether it’s sensible from a wear-and-tear perspective or not, the rider is at least not restricted in this regard. We like that.

The power meter does what it’s supposed to do: it skips sophisticated calibration tricks, pairs quickly, auto-zeros, and delivers precise watt, cadence, and left/right balance data. What more could you want?

  • Sram RED AXS 2024 in ReviewSram RED AXS 2024 in Review
  • Sram RED AXS 2024 in ReviewSram RED AXS 2024 in Review
  • Sram RED AXS 2024 in ReviewSram RED AXS 2024 in Review
  • Sram RED AXS 2024 in Review

Conclusion

Sram RED AXS
Model year: 2024
Test duration: 5 months
+ Lever ergonomics
+ Top single-finger braking performance
+ Shifting faster, more precise, and still crisp
+ Low weight
+ Functionality of the power meter
o Comes at a price
- Grip rubber gap
BB verdict: Currently one of the best options on the market.

Overall, the Americans have done an excellent job updating their top-tier group. The new Sram RED AXS impresses with its low weight, improved ergonomics, and excellent shifting and braking performance.

The integrated power meter is a worthwhile addition to the overall package, provided you're confident in your choice of chainring configuration. From our perspective, it's a clear must-have.

Compared to the premium group of their biggest competitor Shimano, Sram has significantly narrowed the gap with the RED AXS, if not closed it entirely. To be completely honest, the choice between RED AXS and Dura-Ace Di2 now comes down to personal preference and no longer depends on functionality or weight.

  • Sram RED AXS 2024 in Review