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First Look: The New SRAM RED AXS is Lighter and More Refined

We all knew it was coming — the new SRAM RED AXS groupset is finally here! I got mine last week and plan to give it a review. Before we do, let's take a closer look at what's changed for SRAM's new and improved flagship road drivetrain.

Written by: Bruce Lin

Published on:

Posted in:Features

SRAM introduced the original 12-speed RED eTap AXS groupset back in 2019, and it’s been largely unchanged since. If you follow tech news or pro road racing, then you probably knew an updated RED AXS group was on its way. Photos were leaked early this year and it’s already been spotted on a few pro bikes. Now, it’s finally here.   

Just like the updated Force AXS group SRAM released last year, “eTap” has been dropped from the name. The new group is now known simply as “RED AXS.”

It is the culmination of many small refinements and the result is a new groupset that weighs less, shifts a bit better, and brakes MUCH better. It has improved shifter ergonomics, more crank length options, more gearing options, and it even comes with a nifty new head unit. 

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The New RED AXS Groupset

I didn’t get my hands on an actual RED AXS group until early last week. I've installed it on one of our ENVE Melee road bikes and got enough miles on it for a short review. If you want to read about how I think it rides, I put my thoughts in a second post:

[button]RED AXS First Ride Review[/button]

Here, we'll cover the tech and everything that’s changed with the new RED AXS update.

New SRAM RED AXS for sale
  • RED AXS is 153 grams lighter than the previous generation. It is the lightest electronic group on the market. 
  • Weight for a full group is 2,461g, or 2,496g with a power meter (weighed with 48/35t chainrings, 172.5mm cranks, a 10-28t cassette, 160mm rotors, batteries, hardware, adaptors, and brake hoses and fluid).   

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  • You can purchase an upgrade kit for an AXS-equipped bike with a “RED AXS aftermarket groupset.” This retails for $3,000 and includes the new shifters/brakes, front and rear derailleurs, a chain, brake rotors, a battery charger, a front derailleur setup tool, and the new Hammerhead Karoo 3 and Karoo accessories (no crankset or cassette).

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  • Full groups will start at $3,819 (no power meter or Karoo). You'll have to add up the individual components yourself since there's no full group package for sale (yet). 
  • Oh yeah, there’s a new and updated Hammerhead Karoo 3 bike computer too.


RED AXS Shifters & Brakes

2024 SRAM RED AXS Shifter

Key Features

  • Optimized hood shape fits a wider range of hand sizes
  • More braking power for one-finger braking in the hoods or drops
  • 83g lighter than the previous generation
  • “Bonus Button” provides an auxiliary shift option or ANT+ device control
  • Reach Adjust to personalize fit for more hand sizes
  • Contact Point Adjust to personalize brake engagement
  • Paceline X rotors with an 8g lighter aluminum carrier


  • RED AXS Shifter/brake - $675 (per shifter/brake)
  • Paceline X rotor - $70

New SRAM RED AXS hood shape brake pistonThe biggest beef some had with the previous AXS generation was the shape of the shifter/brake hoods. Some riders found the hoods felt too chunky. Last year’s Force AXS update introduced a revised hood shape that fit smaller hands, and some SRAM-sponsored pros even used the new Force shifters with the old RED eTap AXS group. 

The new RED AXS group features a redesigned hood shape that is much sleeker — it's longer and slimmer, which supports the palm more and allows for more finger wrap.

This was achieved with a new piston layout inside the lever and a new pivot location for the carbon brake levers. The levers have been moved forward so they’re less likely to pinch your fingers or bottom out on the bar during hard braking.

SRAM RED AXS Shifter hood shapeActuating the brakes now requires 80% less effort in the hoods and 33% less effort in the drops, meaning it’s now possible to brake with a single finger from either position.

This might be the feature I'm the most excited about. I one-finger brake on my mountain bikes, but with every road group I've ever used, I've always used two fingers. I was skeptical about one-finger braking from the hoods, but it really works. These brakes are impressively powerful, and they might be my new benchmark for hydraulic road disc. 

The lever reach and contact point offer a lot of adjustment to suit your preferences. The reach adjust for the levers is now easily accessed through a small rubber door on the front of the levers while contact adjust is hidden in a convenient spot behind the rubber hoods. The reach adjust provides A LOT of adjustment, so even riders with smaller hands should be able to get an easy-to-reach lever position. 

2024 SRAM RED AXS brakes

The brake calipers have been slimmed down too with machined cutouts in the caliper bodies. They also have “better pad clearance” so you should get less brake rub, especially when wrenching on the bars out of the saddle. The Paceline X brake rotors have lost some weight too thanks to a lighter aluminum carrier design.

RED AXS Front Derailleur

2024 New SRAM RED AXS front derailleur

Key Features

  • Refined cage shape for faster and more accurate front shifts
  • New setup tool
  • 3g lighter 


  • Front Derailleur - $450
  • Front Derailleur Setup Tool - $7

The big change with the RED AXS front derailleur come in the form of a narrower cage for better control of the chain, resulting in crisper, faster, and more reliable front shifts. The old eTap AXS front derailleur wasn’t the worst, but SRAM is definitely trying hard to bury its spotty reputation with front shifts. 

SRAM RED AXS front derailleur setup tool

The front derailleur also comes with a new setup tool designed specifically for RED AXS. It aligns the front derailleur and holds it in place as you torque the mounting bolt. This ensures the derailleur is in the correct position (something I’ve seen more than a few AXS owners struggle with) to ensure it shifts as well as possible.

The RED AXS front derailleur uses the familiar Yaw cage technology and a new auto trim feature to prevent rub and rasp. It can be mounted in two different positions to fit standard 46/33T, 48/35T, and 50/37T chainrings or Pro 52/39T, 54/41T, and 56/43T chainrings.

RED AXS Rear Derailleur

New 2024 SRAM RED AXS rear derailleur

Key Features

  • Orbit chain management technology
  • 16g lighter than the previous generation
  • Compatible with cassettes from 10-28T to 10-36T
  • Larger X-SYNC pulleys for increased efficiency


  • RED AXS rear derailleur - $700

The heart of the RED AXS group is mostly the same. It still has the Orbit Fluid Damper that improves chain retention in rough terrain. Some material has been shaved off the aluminum derailleur body to reduce weight, and the size of the pulley wheels (which have ceramic bearings) has been increased to 14T to improve efficiency (and looks). 

The new RED AXS derailleur comes in a single cage length that can handle cassettes ranging from 10-28T up to 10-36T and it is 2x or 1x compatible.

RED AXS Crankset, Chainrings, & Power Meters

New 2024 SRAM RED AXS crankset power meter crank arms chainrings

Key Features

  • Hollow carbon crank arms that are 29g lighter than the previous generation
  • Quarq power meters are fully integrated into the chainring(s)
  • Standard 50/37T, 48/35T, and 46/33T chainring options
  • Pro 56/43T, 54/41T, 52/39T chainring options 
  • 38-46T 1x and 48-50T Aero 1x chainring options
  • 160, 165, 167.5, 170, 172.5, and 175mm crank arm length options


  • Crankset - $700
  • Crankset w/ power meter - $1,200
  • Crank arms - $400
  • 2x chainrings -  $300
  • 1x chainrings - $135
  • 1x aero chainrings - $240
  • Power meter kit (w/ chainrings) - $800

The biggest news with the crank is the addition of shorter crank arm length options. To stay on top of current fit trends, the RED AXS crank arms are available in shorter 160, 165, and 167.5mm lengths. The RED AXS crank arms are still made of hollow carbon, but a new carbon layup means the crank arms have shed 29 grams. It continues to use the SRAM DUB spindle. 

Strong riders and flatlanders can now purchase larger “Pro” chainring options, but otherwise, the chainring and power meter options are largely the same with a 13-tooth gap for all 2x chainring options for fast shifts. 

The AXS power meter has been slimmed down slightly, but it is still the same excellent Quarq-based unit with +/-1.5% accuracy. Some riders may be disappointed that RED AXS power meters are still integrated with the chainring(s) to reduce weight. Fortunately, the machined chainrings have an impressively long lifespan. Several riders here at TPC use them and so far none have needed to replace them in the last 4 years and they definitely ride a lot. 

If and when you do need to replace your power meter/chainrings, SRAM has a recycling program. If you take it to an affiliated bike shop, you will get half off a new chainring/power meter combo and the old one will be recycled. It's expensive, but my guess is, if you can afford this groupset, that's a minor concern. 

Cassette & Chain

New SRAM RED AXS cassette and chain

Key Features

  • 10-28T, 10-30T, 10-33T and 10-36T cassette options
  • Five one-tooth jumps on 10-28T, 10 30T, and 10-33T cassettes
  • One-piece machined steel X-DOME design for weight savings
  • Rainbow colorway available in all cassette sizes
  • Revised RED chain is 13g lighter


  • XG-1290 Cassette - $390
  • XG-1290 Cassette (10-36t) - $410
  • XG-1290 Cassette (rainbow) - $450
  • XG-1290 Cassette (10-36t rainbow) - $470
  • RED Chain - $89
  • RED Chain (rainbow) - $99

The main change with the RED AXS cassette is the addition of more size options. SRAM has kept the 10-28T and 10-33T, eliminated the 10-26T, and added new 10-30T and 10-36T RED cassette options. The cassettes feature at least 5 one-tooth jumps at the top end to keep the gearing tight where it’s needed. 

new 2024 SRAM RED AXS rainbow cassette and chain

All RED AXS cassettes are still machined out of one-piece of steel using SRAM’s X-DOME construction to keep weight low. All cassette sizes are also available in the rainbow oil slick color if you want to add some bling to your bike. 

The Flattop RED chain has shed some weight thanks to redesigned cutouts in the outer and inner plates. It uses HollowPin construction and Hard Chrome plated inner link plates for increased strength and wear resistance. Like the cassettes, it’s available in silver or rainbow. 

Hammerhead Karoo (3)

New 2024 Hammerhead Karoo 2.1


  • Industry-leading touchscreen display
  • 64GB of memory, 4GB of RAM
  • Multi-band GNSS 
  • Connectivity with SRAM AXS products
  • Regular software updates
  • New companion app
  • 15+ hours of battery life


  • Karoo computer - $475
  • Karoo heart rate monitor - $64
  • Karoo mount - $40

The Hammerhead Karoo 2 has been one of my favorite head units for a while. One of its selling points is that it gets regular software updates. The Hammerhead team is always adding new and improved features, fixing bugs, and tweaking things based on feedback from its community of users. However, the Karoo 2 hasn’t had any major hardware updates since it was released in 2021. 

Like RED AXS as a whole, the new Karoo 3 (though the marketing materials just say "Karoo" it's the third iteration so I'm saying "Karoo 3" to stay in line with other reviewers) doesn't get a massive overhaul. It’s more of a refinement.

The shape of the unit itself is a bit slimmer. Storage has increased from 32GB to 64GB. Battery life has increased from 14 hours to 15+ hours (it can go longer depending on settings and usage). There’s also a new companion app that will allow users to upload rides without WiFi (my biggest complaint with the old browser-based dashboard) and manage the Karoo without removing it from the handlebars.

The Karoo also connects with SRAM AXS so you can control the Karoo with the Bonus Buttons or use the Karoo to change drivetrain settings or adjust your derailleur while riding.    

Hammerhead Karoo 2.1

Otherwise, it still has the best color touchscreen in the business. The Karoo runs on an Android OS, so navigating the unit feels like using your smartphone. It has the best maps and navigation that I’ve used too. There’s also new structured workout support that should let you start and edit workouts on the fly, which I’m eager to try. 

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