The Trek Madone SLR 9 introduces a new aero concept, upping the ante with their IsoFlow technology. This transforms it from a pure aero bike into a true all-rounder, effectively pushing the Émonda into retirement. But can the Trek Madone SLR 9 in review shine not just with its eye-catching paint job but also in that crucial photo finish?
US brand Trek have always stood for high-end engineering, committed to peak performance backed by a strong WorldTour team. The newly introduced 2024 Madone SLR 9 Gen. 8 aims to blend the climbing prowess of the Émonda with the proven aerodynamics of the Madone, promising uncompromising race-readiness with an added dose of comfort. Designed for blistering sprints, endless climbs, and rapid descents, it’s built to excel in every racing situation. And with the exclusive ICON Interstellar finish, the Madone SLR 9 makes a statement within the Rari Racing Team’s lineup, turning heads even in the pro peloton – guaranteed! We put the SLR 9 through its paces in a head-to-head test to see how it fares against the competition.
ISS or IsoFlow? –The Trek Madone SLR 9 AXS in detail
With its striking appearance, the Trek Madone SLR 9 could be likened to the Lightning McQueen of race bikes. Trek’s Project One configurator allows for custom designs and one-off finishes, and our test bike’s ICON Interstellar paint scheme, with its mesmerising oil slick effect, makes the frame shimmer in every imaginable colour depending on the light. However, this finish adds a hefty € 4,000 to the price, which is already a steep € 13,999 for the base model. That aside, the real talking point is the “hole” in the frame. Trek’s IsoFlow technology, consisting of a distinctive cut-out in the seat post first introduced with the previous model, has been refined with a more delicate design and new carbon fibres, aiming to deliver greater comfort while further minimising weight. Riders with long legs who prefer a more compact frame geometry should opt for the longer of the two seat post versions. The saddle height can be adjusted using Trek’s Seat Dome system, although the split-seat post design offers just a few centimetres of adjustment. Trek are pursuing their own approach to compliance with the IsoFlow system, aiming to combine the comfort of an endurance bike with the stiffness of a thoroughbred race machine. Exciting stuff!
With IsoFlow and a new aero design, the Madone proves that comfort and speed aren’t mutually exclusive.
The 52 mm Aeolus wheels offer excellent performance in crosswinds and at high speeds.
Aero bottle cages and bottles save watts — Trek make it possible!
The new American all-star racer joins the ranks of all-round race bikes from the likes of Specialized and Lapierre. Compared to the former aero-focused Madone with its deep tube profiles, this all-rounder takes on a fresh concept that promises the same performance as its predecessor while also saving weight. The Trek Madone SLR 9 on test weighed in at 7.24 kg without a tubeless setup — we’ve had even lighter builds of this bike in the office earlier this year. Borrowing the slim seat stays from the Émonda, the Trek Madone SLR 9 frame remains surprisingly light despite its aerodynamic design. Aero bottles and a broad down tube are designed to channel airflow efficiently along the sides, allowing it to achieve similar speeds to the previous pure-aero model, even without being a dedicated aero bike.
The Aero RSL cockpit may look bulky at first, but it delivers in terms of ergonomics and control.
The new full-system foil aero frame design optimises airflow and reduces drag.
DThe ICON Interstellar finish makes the Madone shine – a real eye-catcher, whether you’re on a group ride or stopping for an ice cream!
| Size | XS | S | M | ML | L | XL |
|---|---|---|---|---|---|---|
| Top tube | 517 mm | 532 mm | 545 mm | 557 mm | 568 mm | 584 mm |
| Seat tube | 404 mm | 440 mm | 476 mm | 512 mm | 548 mm | 609 mm |
| Head tube | 100 mm | 121 mm | 136 mm | 150 mm | 172 mm | 201 mm |
| Head angle | 71.6° | 72.2° | 72.9° | 73.5° | 73.8° | 73.9° |
| Seat angle | 73.8° | 73.8° | 73.6° | 73.4° | 73.4° | 73.4° |
| Chainstay | 410 mm | 410 mm | 410 mm | 410 mm | 411 mm | 412 mm |
| BB Drop | 72 mm | 72 mm | 70 mm | 70 mm | 68 mm | 68 mm |
| Wheelbase | 971 mm | 976 mm | 981 mm | 980 mm | 990 mm | 1007 mm |
| Reach | 370 mm | 378 mm | 384 mm | 389 mm | 394 mm | 402 mm |
| Stack | 507 mm | 530 mm | 546 mm | 562 mm | 582 mm | 610 mm |
On interstellar mission: The specs of the bike
Trek rely almost exclusively on in-house Bontrager components for the Madone SLR 9’s build. The Bontrager Aeolus RSL 51 wheels, weighing in at 1,425 g with a rim depth of 52 mm, already impressed us in our performance wheelset group test, thanks to their excellent aero performance and versatility. Their wide 24 mm internal rim width is designed to create a larger contact patch when paired with the 28 mm Pirelli P ZERO tires and offer improved stability. For those seeking extra cushioning, the frame accommodates up to 32 mm wide tires.
The ergonomic Trek Aero RSL cockpit flares out by 3 cm in the drops, measuring 39 cm wide at the tops. This 6-degree flare is intended to enhance aero efficiency in the hoods while offering plenty of control in the drops for descents and sprints. Shifting and braking duties are handled by the latest SRAM RED AXS groupset, complete with a Quarq power metre, which performs reliably and helps keep the Madone SLR’s overall weight down. You get a 48/35 t chainring up front, paired with a 10–33 t cassette at the rear, promising ample range for both steep mountain pass climbs and finish line sprints.
Das neue Aero-Konzept des Madone SLR sieht einen Aero-Flaschenhalter und passende Flaschen vor. Durch diese Kombination soll man schneller als ohne sein und bis zu 2 Watt bei 45 km/h einsparen – Kleinvieh macht auch Mist!
TREK MADONE SLR 9 AXS
€ 18,199
Specifications
Seatpost Madone Aero Carbon Seatpost, 0mm Offset, Short Length Shaped
Brakes SRAM RED AXS HRD 160/160 mm
Drivetrain SRAM Red AXS 2x12
Stem Trek Aero RSL Road 100 mm
Handlebar Trek Aero RSL Road 390 mm
Wheelset Bontrager Aeolus RSL 51
Tires Pirelli P Zero Race 700 x 28c
Cranks SRAM RED AXS DUB 172,5 mm
Cassette SRAM RED XG-1290 11-32
Technical Data
Size XS S M ML L XL
Weight 7.24 kg
Specific Features
Iso Flow Project One Paint
Aero bottles
Ready for Light Speed? The Trek Madone SLR 9 AXS in review
The Trek Madone SLR 9 looks like a rocket – but can it deliver both aero speed and comfort? Out on the road, it impresses as a thoughtfully designed aero all-rounder, but how versatile can an aero bike actually be? Once it’s up to speed, the Madone is capable of accelerating almost like a rocketship, and it will hold the pace effortlessly over longer distances. While not as punchy off the line as the S-Works Tarmac SL8 or the BMC Teammachine R01, the Madone SLR 9’s short chainstays and weight-optimised design make it one of the most nimble climbers on test, leading the charge in hilly terrain.
Thanks to the revised IsoFlow technology at the rear, it absorbs vibrations more effectively than most of the competition on test, making the Madone SLR the most comfortable race all-rounder – without feeling sluggish like an endurance bike. Although the cockpit might look bulky at first glance, its ergonomic tops and flared drops won us over, providing excellent control even during all-out sprints.
With its balanced geometry and innovative damping technology, the Trek Madone SLR 9 achieves an impressive level of both aero efficiency and comfort, and its light weight makes it feel well-rounded, on par with the S-Works Tarmac SL8. While the striking ICON Interstellar paintwork makes it stand out from the crowd, the Madone performs like a well-balanced all-rounder.
Compared to the Rari support car, the Trek Madone SLR isn’t just fast but also comfortable, thanks to the IsoFlow technology.
What racer is the Trek Madone SLR 9 AXS for?
True to the motto “don’t race what you can’t replace,” the Trek Madone SLR 9 with its pricey Project One finish is especially suited to riders who value exclusivity. For those who can afford it, the Madone SLR 9 is the ideal all-rounder – perfect for fast sprints, tight technical races, and long training sessions. While aggressive, it’s less so than a pureblood aero specialist, even impressing beginners with its versatility, precision, control, and best-in-class compliance. This doesn’t just make it a contender for a photo-finish sprint, but also an excellent choice for long, flat races where comfort is key.
Our conclusion on the Trek Madone SLR 9 AXS
The Trek Madone SLR 9 impresses as a versatile aero all-rounder, combining high comfort with an effective blend of aerodynamics and lightweight. Its innovative IsoFlow technology sets the bar for race bike comfort, and the striking look is a true head-turner. The premium € 4,000 finish underscores its exclusivity, although it remains firmly in the high-end segment even without it. While less aggressive and explosive than the test winner, it scores for its compact geometry and highly balanced, intuitive handling.
Tops
- Fast, responsive cornering
- Excellent compliance thanks to IsoFlow
- Well-balanced mix of comfort and stiffness
Flops
- Very limited seat post adjustability
More information at trekbikes.com.
The test field
This bike was tested as part of the 2024 race bike comparison test – an overview of this comparison test and all other tested race bikes can be found here:
All bikes in review: BMC Teammachine R 01 | Canyon Aeroad CFR | Cervelo Soloist | Falkenjagd Aristos RSR | Lapierre Xelius DRS 9.0 | Specialized Tarmac SL8 | Trek Madone SLR 9 | Wilier Filante SLR
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Words: Jan Fock Photos: Jan Richter
