SRAM Red AXS chainset and derailleur on an S-Works Aethos

SRAM launches new Red AXS groupset: the lightest on the market, designed for ‘effortless’ riding

SRAM's new flagship groupset is all about refining the experience for every rider – instead of adding sprockets or new shifting systems it has focused on light brake feel, comfortable ergonomics, smooth front shifting, more wireless connectivity and expanded gearing choices... and of course saving grams


Photos: Alessandra Bucci Words: Simon Smythe

When you won all six Grand Tours of 2023, what are you going to do in 2024? Launch a new flagship groupset, that’s what. It’s called building on success. SRAM, which only equips four teams in the men’s WorldTour – including of course Visma-Lease a Bike – had a pretty incredible year by anyone’s standards. 

So where will the famously disruptive US brand take road cycling groupsets next? Well, the direction of new Red AXS seems to be aimed at consolidating SRAM’s position as the winningest component brand rather than ripping up the rule book and starting again. 

S-Works Aethos with SRAM Red AXS

SRAM burst onto the scene in the late-1980s with its bar-mounted Grip Shift system, shook up mechanical shifting with DoubleTap in the 2000s, was first of the ‘big three’ with wireless shifting in 2015 and most recently reimagined gear ratios with Red eTap AXS in 2019. But this time there are no big surprises – no 13th or even 14th sprocket, new protocol, electronic braking or anything as mindblowing as some of its previous innovations – and actually all the components of new Red AXS are backwards compatible with existing SRAM 12-speed electronic groupsets including derailleur batteries. Instead, SRAM says it has listened to rider feedback, watched the market and done a careful analysis of what worked and didn’t work with outgoing Red eTap AXS, closed performance gaps and come up with a refined and improved version that it says is more “effortless”. Additionally – and this was undoubtedly a big objective – it has dropped 153g, undercut the weight of Shimano Dura-Ace 9200 and now claims to be the lightest electronic groupset on the market. This is a feather that every component manufacturer wants in its casquette and one that SRAM previously owned with its mechanical Red groupset.

The new Red AXS (‘eTap’ has now been dropped) brings, according to SRAM, “light brake feel and comfortable ergonomics, smooth front shifting, fully wireless connectivity and expanded gearing choices to fit every rider and their needs … new shift points and more brake adjustability while still shaving grams off every component.”

Controls

Perhaps it’s the shift/brake controls that have had the biggest makeover. Longer, slimmer in circumference at the hood body and with a lower pommel (the protruding section directly above the brake lever), SRAM’s aim here was to allow more fingers around the hood body for better control with the smaller pommel making one-finger braking from the hoods more accessible. Moving the position of the hydraulic piston from the pommel into the body has made this new lever architecture possible and SRAM says additionally the design requires less force to activate the brake. There are even figures for it: 80% less effort when braking from the hoods and 33% less effort when braking from the drops (compared with outgoing Red).

SRAM Red AXS shifters

The ribs and textures on the hoods are not only there for grip but also to help set them up correctly: for example, the bottom of the rib pattern on the outsides of the hoods should be parallel to the ground. Reach adjust is via a 2.5mm Allen key on the front of the lever. SRAM has added ‘Bonus Buttons’ to the insides of the pommels, which are thumb operated and programmed out of the box as auxiliary shifters doing the same job as the paddles (i.e. right for a harder gear, left for easier, both together for front shift) but which can be programmed via the AXS app to control other ANT+ devices/swipe between computer screens. As before, the CR2032 coincell batteries are estimated to last around years based on 15 hours a week of riding.

SRAM Red AXS brake rotor and caliber

As for the brakes themselves – Red AXS is hydraulic disc brake only – SRAM has redesigned the calipers and claims that they're stiffer, lighter and offer better pad clearance than before, contributing to a saving of 83g combined with the new shifters. The Paceline X rotors get lighter aluminium carriers – "the lightest we've ever made",  come in 140mm or 160mm sizes and are the Centerlock type.

Derailleurs

There’s just one front and one rear derailleur for all chainring and cassette sizes (see below). The front has a narrower front cage that SRAM says allows faster and more accurate shifts. The rear has a larger lower pulley with ceramic bearings – which looks like the Magic Pulley of Eagle XX and XX SL groupsets but actually isn’t. It’s for better chain articulation and reduces chain friction very slightly.

SRAM Red AXS rear derailleur

There’s an orbit fluid damper to control a bouncing chain over rough terrain. The rear derailleur can be used with 2x or 1x configurations on road or off. It looks a little more hollowed-out than before and SRAM claims it’s 16g lighter. Both derailleurs are compatible with existing batteries.

Crankset

Aesthetically it's not that different from the previous version, but it has sharper, straighter, cleaner lines. There are 2x and 1x (‘Red 1’) cranksets available. An optimised layup for the hollow carbon crankarms saves a claimed 29g and SRAM has added a 160mm crank length for the first time.

SRAM Red AXS chains

Sizes are now 160mm, 165mm, 167.5mm, 170mm, 172.5mm and 175mm and the one-piece 2x chainrings come in 50/37, 48/35 and 46/33. There are aftermarket ratios (as used by the pro teams) which comprise 52/39, 54/41 and 56/43. Cranksets run on SRAM’s DUB spindles as before. There are spider-based power meter options for both with +/-1.5% accuracy.

Cassette and chain

SRAM has ditched the 10-26 cassette but added 10-30 and 10-36 options to the 10-28 and 10-33 making a total of four. These install on the existing XDR driver body and are made from one-piece machined steel – SRAM’s X-DOME tech. As with the new chain, these are all available in the rainbow/oil slick colourway.

SRAM Red AXS cassette from above

The Flattop chain remains but now it has cutouts and hollow pins that SRAM claims saves 13g. SRAM says the hollow pins are stronger than solid ones and, with the hard chrome inner plates and rollers, says the chain overall offers better strength and durability.

New Hammerhead Karoo

It deserves its own review – and it will get one a soon as I’ve spent more time with it – but SRAM has launched a new Hammerhead Karoo head unit (it owns Hammerhead) alongside Red AXS that promises deeper integration with the groupset than any other computer.

Hammerhead Karoo on an S-Works bar

Since it automatically pairs with the AXS system it can supply insights into your shifting, time spent in gear as well as power data and the ability to (for example) configure the Bonus Buttons directly without having to use the phone app. So far I can say it is more smartphone-like than any bike computer I've ever used. The touchscreen and the display are stunning.

Ride impressions

If you’re going to review the lightest electronic groupset on the market, you need a suitably light frame to put it on. I’ve heard so much about the S-Works Aethos, even rumours that cycling journalists have liked it so much that they’ve bought one with their own money! The frame in a size 56 is said to weigh a ludicrous 585g. I just had to get on the phone to Specialized and ask if they could lend me one for a special assignment. So senior brand manager Symon Lewis pulled some strings and one was duly shipped over from California with this beautiful, subtle limited-edition ‘glacial metallic’ paintjob. It was built up with the new Red AXS groupset with a power meter chainset, Roval Alpinist CLX II wheels with S-Works Turbo 28mm tubeless tyres and an S-Works Power with Mirror saddle. It had a Roval Alpinist alu stem and S-Works carbon bar. The actual weight was 6.4kg – very impressive bearing in mind that these are standard components.

So far I haven’t mentioned aesthetics, but I do particularly like the amount of polished silver here. With the slightly retro silver-blue of the Aethos and the silver wheel decals, this is one of the classiest looking bikes I’ve seen in a long time.

The ride is all class too. The almost magical lightness of the Aethos showcased the new lightest electronic groupset on the market perfectly. It would be difficult for me to verify SRAM’s data about how much less force on the levers is required to brake, but I wouldn’t dispute it having experienced it. It’s simply incredible stopping power – for hardly any input, but at the same time plenty of progression so that if you need to back off slightly (with your one finger) you know it. SRAM says the Paceline X rotors are quiet and it's only now occurred to me once I've already given the bike back that I didn't hear a single squeak let alone a squeal or shriek from the disc brakes.

Shifting – as you’d expect from the mostly ‘if it ain’t broke don’t fix it’ approach to the new groupset, it’s the signature SRAM ‘beep boop’ that's similar to the feel of a MacBook trackpad, it shifts evenly and quietly across the whole cassette without that gunshot sound that you sometimes get as you hit the smaller sprockets with other groupsets. SRAM doesn’t claim shifting is faster than that of its competitors and this would be difficult to call. Certainly, though it excels at smoothness. Front shifting is impeccable, but it did occur to me that I hadn’t done all that much of it during my time with the bike thanks to AXS gearing. With the 48/35 chainrings and 10-36 cassette I was in the big ring most of the time, which is of course one of the great things about AXS.

SRAM Red AXS

A feature of the new groupset that SRAM doesn’t talk about in its press release is the actual shape of the carbon brake levers and paddles tucked in behind them. The redesigned levers kick significantly outwards when the pommel is vertical. With a flared bar they would line up with the drops, but with a more traditional bar without flare – like the one I was using – they don’t, so when you’re in the drops the levers are not directly in front and for me not in the optimal position for braking and shifting. However, as SRAM points out, most riders, including pros, spend more time on the hoods than in the drops, so it’s clearly the wrist ergonomics of this position that SRAM has aimed to optimise. And at the moment flared levers just look cool.

I was won over immediately by the Bonus Buttons on the insides of the hoods and would leave them exactly as they are – as auxiliary shifters. In an aero-hoods position it makes perfect sense to be able to shift with thumb pressure rather than unwrapping a little finger and reaching down to the paddle.

In summary, "effortless" is an accurate description of the new Red AXS. I’d say SRAM has achieved everything it set out to achieve in making all the components work easily, lightly, smoothly and harmoniously. Refining and improving – rather than creating a new ‘ecosystem’ – and ensuring everything is backwards compatible shows that SRAM has read the room, and that gets my vote. And Red AXS and the S-Works Aethos complement each other perfectly. For the ultimate ride experience it’s hard to see what could beat this setup. It’s as close to a match made in heaven as you’ll find. And although there’s not much anyone can do about Tadej Pogačar as I write, there’s no doubt SRAM’s WorldTour teams will be onto a winner with this groupset.

SRAM Red AXS-equipped bikes are available immediately from all the main brands, including this actual S-Works Aethos LTD build, which will cost £12,500 from Specialized – £500 lower than the S-Works Aethos with outgoing SRAM Red eTap AXS.

Check out SRAM’s website for all the details and individual component prices.



Photos: Alessandra Bucci Words: Simon Smythe


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