2024 SRAM Red AXS groupset review

Improvements to braking performance and shifting bring SRAM's new flagship Red AXS groupset on par with Shimano Di2 Dura-Ace R9200.

The groupset's claimed 154g weight saving over the previous generation also makes it the lightest electronic disc brake drivetrain on the market, if such claims matter to you.

The improved shifter ergonomics, with a new hood shape and lever profile, are the biggest change from the outgoing Red eTap AXS groupset.

Backwards compatibility with existing 12-speed AXS components means you can mix and match – want to run Red levers and brakes with the first-generation Force AXS from 2019? You can. Considering upgrading your Rival AXS-equipped bike? That’s easy too.

So unlike the more subtle differences between Shimano's Dura-Ace Di2 R9200 and Ultegra Di2 R8170, there are arguably more compelling reasons to step up to Red AXS if you’re already in the SRAM stable.

We've covered the full tech details behind the new SRAM Red in our news story; here I'll focus on its performance. As part of this launch, SRAM has also introduced a new Hammerhead Karoo bike computer, while Zipp – another brand in the SRAM stable – has collaborated with Goodyear on tyres designed specifically for its wheels.

SRAM Red AXS setup

As it is wireless, setting up any SRAM AXS groupset is about as simple as it gets.

The exception was its front derailleurs – in addition to moving in and out, SRAM front derailleurs arc as they move to limit the chance of the chain rub.

SRAM provides a new setup tool with Red AXS to accurately set the angle and gap of the cage in relation to the chainring. This holds the derailleur in place as you torque it into position. The tool comes in two sizes to suit different chaninrings.

It was easy to get the front shifting spot on the first time on my test bike using the tool.

The groupset is paired via the rear derailleur by pressing the AXS button on the derailleur body until it flashes green.

You then press the AXS buttons on each component until the rear derailleur light flashes rapidly. This indicates pairing the rear derailleur, which houses the brains of the system, was successful.

The groupset is quicker to set up versus a wired or semi-wireless electronic groupset.

You can pair the groupset to the AXS app once everything is linked

This enabled you to assign actions to the controls beyond the default settings. The function of wireless ‘Blips’ (secondary small buttons) are also set in the app.

The redesigned shifters feature a hidden button on the inner side of the hood pommel. This can be assigned to different functions.

In addition to the usual logic, I set mine up to shift the front derailleur, making actuation a single button press from the hoods.

This button can also be assigned to control ANT+ devices, such as a rear radar light, lights or to scroll through screens on your head unit. A similar button is included on Shimano Ultegra Di2 and Dura-Ace Di2 can groupsets.

Compatibility with Wahoo and Garmin computers has yet to be confirmed by SRAM. At the time of publication, beyond displaying the standard gear information and power meter data, Red AXS doesn’t talk to my Garmin Edge 830 Solar.

Brake bleeding is done via SRAM’s ‘Bleeding Edge’ ports – a carry over from the previous calipers.

These ports are push-fit, rather than more fiddly threaded ports on a standard caliper. Speaking from experience, this makes it quicker, cleaner and easier to maintain your brakes.

The brake’s contact point adjustment and lever reach are independently adjustable.

The lever’s reach is adjusted via a 2.5mm hex bolt on the inside of the lever shaft, offering up to 15mm adjustment at the lever tip.

The brake contact point adjuster offers four positions, effectively equating to four lever stroke lengths – shorter travel resulting in a firmer brake feel, while longer travel brings about a more progressive feel

I left the contact point adjustment as stock in the 2nd position from full lever stroke.

SRAM Red AXS drivetrain performance

SRAM Red AXS rear derailleur

SRAM has noticeably refined rear shifting while maintaining swiftness.

Shifting through the full 12-speed cassette range is noticeably quieter compared to the previous generation, especially when moving down from the largest to smallest sprockets.

Shifting in reverse from the 10t cog upwards is very smooth and quick.

The new derailleur’s larger X-Sync pulley wheels –up from a pair of 12 tooth pulleys to a larger 14 tooth lower pulley and 12 tooth upper – help smooth the chain’s path as it engages the smallest gears in the range.

The previous rear derailleur's smaller pulley wheels could feel notchy when pedalling at higher power and lower cadences, especially down in the smallest 10-tooth sprocket.

This sensation has now been almost completely removed.

The tooth pattern on the pulleys is noticeably squarer than traditional pulleys. SRAM claims this helps engage the chain earlier for better chain retention and smoother shifts.

In combination with the Orbit fluid damper, which has been retained to help keep chain tension in check and reduce unwanted bounce, it makes for a drivetrain that doesn’t get upset by poor road surfaces, bumps, and potholes.

SRAM Red AXS front derailleur

The new front derailleur has had a substantial makeover with a revised geometry, with the linkage on the cage shifting backwards a little, and new cage profile introduced (it’s both longer and slimmer).

This has had the intended effect of speeding up the front shifts – gone is the occasional hesitancy of the chain to engage when shifting up to the big chainring.

The addition of the electronic auto-trim function means I’ve been unable to get the chain to rub the cage, even when cross-chaining.

My test groupset paired the smallest 46/33T crankset with the widest 10-36t cassette option. Bigger chainrings may put this under greater strain.

Though it's psychological, assigning the new bonus buttons to shift – as opposed to pushing both triggers simultaneously – results in a faster feeling shift, even though the motor in the front derailleur is unchanged.

In all, these subtle changes add up to shifting performance and smoothness that now feels a match for Dura-Ace Di2’s slickness.

SRAM Red XG-1290 cassette

SRAM's one-piece X-Dome cassettes are easier to fit compared to Shimano and Campagnolo's multi-piece cassettes.

The cassette's ramps and profiles make for quick downshifts and upshifts are smooth and stable too.

I haven’t experienced any problems with the chain settling into place even when shifting under load at lower speeds when climbing or when downshifting under load when out of the saddle sprinting.

There are four cassette options:

• 10-28t
• 10-30t
• 10-33t
• 10-36t (the option I used for this review)

SRAM Red cassette ratios

	1	2	3	4	5	6	7	8	9	10	11	12
10-28t	10	11	12	13	14	15	16	17	19	21	24	28
10-30t	10	11	12	13	14	15	17	19	21	24	27	30
10-33t	10	11	12	13	14	15	17	19	21	24	28	33
10-36t	10	11	12	13	15	17	19	21	24	28	32	36

SRAM Red AXS crankset with integrated power meter spider

The crankset, which combines carbon fibre crank arms with a one-piece chainring – and, in this instance, a spider-based power meter – divides opinion.

To my eye, the crankset looks stunning. They also shift terrifically, which is due to their one-piece construction, which results in a stiffer chainring, according to SRAM.

SRAM also claims the one-piece design gives better chain retention over the original two-piece Red eTap cranksets.

On the other hand, you lose the scope to customise your chainring ratios independently. And, when you eventually wear out a ring, you’ll need to replace both simultaneously, which will cost £300 / $300 / €335 for a standard pair.

In comparison, an outer Dura-Ace FC-9200 chainring is priced at £169.99, while the inner £39.99.

If you have a power meter-equipped Red AXS crankset, a full-price replacement set costs $800 / €895 / £800.

Partially mitigating this, SRAM offers a trade-in through local SRAM dealers for a half-price, like-for-like replacement/recycle program.

The already wide range of options has grown, with 2x chainring options of 46/33, 48/35, 50/37, 52/39, 54/41, and 56/43T. There are five 1x chainrings too (42-50T at two tooth intervals). All can be had power meter equipped.

Crank arm lengths have expanded too, adding a short 160mm option to the 165, 167.5, 170, 172.5, and 175mm lengths.

SRAM Red AXS chain

The final piece of the drivetrain puzzle is the chain.

The new chain retains the same flat-top design but now features slotted plates and hollow pins. SRAM claims the new design is both lighter and stronger than the previous chain.

It’s also available in a rainbow oil slick colourway and the polished steel version on test.

Our full-length uncut chain (with 120 links) and link weighed in at 249g compared to the previous SRAM Red eTap AXS chain, at 262g.

On the bike, the chain hasn’t dropped, chattered or done anything untoward throughout testing.

SRAM Red AXS shift-brake controls

The large pommel that housed the hydraulic piston has been a divisive feature of SRAM's drop bar hydraulic brake levers since they debuted in 2013.

Generally, this wasn’t considered aesthetically pleasing and could be problematic for riders with smaller hands.

The new Red AXS units have addressed this with a significantly more compact design.

The new design moves the piston from a vertical position to a horizontal layout. Moving the lever pivot point higher up in the shift lever body also enabled SRAM to shrink the hoods.

The circumference of the hood is reduced too, which is claimed to make it more comfortable for smaller hands.

The hood body is 7mm longer. I thought this could impact my bike fit, but the hood position and shape felt natural in testing.

SRAM’s shift logic remains unchanged, with the right trigger pushing into a harder gear, the left into an easier gear, at the cassette. Pressing both together shifts the front derailleur up and down.

I've always felt the shift logic is intuitive, even if f pressing two buttons at once has felt slightly slower. As mentioned, setting up the new auxiliary buttons for one-button shifting remedies this, assuming you’re happy to dedicate them for this use.

The new triggers have the same defined ribbed surface as the latest Force AXS units – a good thing for a positive, tactile experience.

The carbon lever blades are a radically different shape to the previous generation. These have the biggest effect on the feel of Red.

The lever kinks outwards around a third of the way down its length. In the drops, the lever is within easy reach for 2 to 3 fingers on my large hands.

From the hoods, the lever has a flattened section in its first third. Combined with the new higher pivot position, this makes for brilliant overall brake feel.

SRAM Red AXS braking performance

The new lever design, brake caliper and lighter rotor have all combined to create braking that matches the terrific progressive feel of Shimano’s Servo Wave hydraulics.

SRAM says the new two-piece caliper is machined to make it lighter and stiffer than the previous design.

SRAM has also moved the piston more outboard. According to SRAM, this makes the centre of pressure of the pads on the brake surface more central on the brake track.

The rotor also sports a lighter aluminium carrier, saving a scant 8g, on a 160mm size rotor, over the previous rotor. The rotor track material, as well as the pads, are the same, though.

By actuating on more usable surface area, the effect at your fingertips is huge. The effort required to brake is minimal, and impressively progressive.

There’s a silkiness to the braking, delivering a subtle increase in brake pressure throughout the levers travel – this meant I never over-braked.

The brakes also never felt grabby, even in emergencies.

The 4mm increase in pad clearance results in a reduction in rotor scrape – I never got a hint of it in testing. In the wet, the brakes were easy to modulate and quiet.

That could be down to the design of the brake track on the rotor, which sees new venting gaps, and the new centre of pressure on the pad.

Braking performance and feel were where SRAM had lagged behind Shimano. But this new lever, combined with the new calipers and rotors puts the braking feel and performance on par with Shimano’s best.

SRAM AXS app

The AXS app still offers the best connection of all the electronic groupset apps on the market.

It has the most polished user interface – it’s fair to say Shimano’s e-Tube app looks and feels like it’s designed as a workshop tool.

Firmware updates from your phone, button functions from the app, and ride recording with key data-capturing abilities are all present and correct.

If you have the sensors to record it, the depth of data available has been second to none for years.

It also automatically uploads rides and accompanying data to Strava.

Hammerhead Karoo integration

The integration of Hammerhead’s Karoo bike computer into the SRAM ecosystem – which is included with aftermarket groupsets – is a real step forward.

The computer instantly recognizes your groupset’s configuration, immediately prompting you to select chainring and cassette sizes.

You can now perform most of the functions of the AXS app through the Hammerhead unit, even on the fly. Want to assign blips, hidden buttons or shift triggers to another function as you ride? You can.

I haven’t had a chance to fully test the new unit (a review will come in time) but my early impressions are positive.

Whether it’ll be the unit to tempt me away from more than a decade of Garmin computer ownership remains to be seen.

SRAM Red AXS weight

SRAM Red AXS is as light as you’d expect on a premium groupset – in fact, it's the lightest electronic t disc brake groupset on the market if you believe SRAM.

My test setup combining a 10-36t cassette, and 46/33t power meter-equipped crankset weighed in at 2,548g – 52g more than the SRAM’s claimed lightest configuration but still more than 100g less than the previous generation’s 2,650g in a comparable specification.

It comes up lighter than Dura-Ace Di2 R9200 by 37g, and 57g lighter than Campagnolo Super Record Wireless, according to our scales.

SRAM Red AXS pricing and value

SRAM Red AXS has a retail price of £3,000 / $3,000 / €3,350, for the following components:

• Left & right shift brake controls
• Front & rear brake calipers
• 2x 160mm Paceline X CL rotors
• 1x AXS charger
• 2x AXS batteries
• Rear derailleur
• Front derailleur
• Chain
• Hammerhead Karoo GPS
• All hardware required to fit

The crankset and cassette comes on top of this, bringing the total cost to £4,090-£4,110 ($4,090-$4110) / €4135-€4165) for a non-power meter set up, or £4,590-£4,610 ($4,590-$4,610 / €4695-€4745) with a power meter.

This assumes that you’ve opted for the standard steel colour cassette – the oil-slick rainbow colourway adds around $60 / £60 to the asking price.

It’s also worth noting that if you want 52/39, 54/41, 56/43, 48T or 52T combinations, you’ll need to purchase crank arms and chainrings separately.

The cranks cost $400 / €450 / £400, while the chainrings are $800 / €895 / £800 (all including the power meter) The single ring power meter option comes in at $500 / €560 / £500.

A non-power meter 48T chainring is $240 / €270 / £240.

Without the power meter, Red AXS comes in less than Campagnolo Super Record (£4,499/$5,399/€5,200), but more than Shimano Dura-Ace Di2 R9200 (£3,593.89).

Of course, real-world groupset prices invariably differ hugely from RRPs, so take these with a pinch of salt.

SRAM Red AXS bottom line

With its latest flagship road groupset, SRAM has addressed the issues of the previous generations of SRAM wireless hydraulic groups.

The new hood shape and lever profiling is a huge ergonomic improvement.

Combined with the new brake caliper design, it’s easily on par with Shimano’s Servo Wave. The added adjustability only enhances this impression.

SRAM’s clever chain management also keeps the drivetrain in check on rough surfaces – although Red eTap AXS was already stronger than its rivals in this respect.

Braking performance has also improved, alongside smoother front derailleur shifting and quieter running. I think Red AXS is now a match for Shimano Dura-Ace Di2 R9200 in sheer performance terms.

The much-vaunted weight reductions are marginal, though, and shouldn’t be a factor that swings a decision either way.

Backwards-compatibility with existing 12-speed components means you can steadily switch over to the raft of improvements when you’re ready. If I was interested in Red AXS, I'd consider rolling upgrades on an AXS-equipped bike rather than upgrading everything at once.