Exclusive first ride review of the 2023 Trek Madone SLR 9 Gen 7 – Trek’s aero comfort revolution?

After introducing the 2023 Trek Madone SLR with its unique look and promising updates, we couldn’t wait to put it to the test. We’ve now had the exclusive chance to swing our legs over the € 15,699 Trek Madone SLR 9 eTap Gen 7. Read on to find out how the new aero bike fares with the reduced weight and complexity of the IsoFlow system.

Trek claim to have developed their fastest bike yet with the all-new 2023 Madone SLR, and caused an uproar in the community while they were at it. When the first photos of the 2023 Trek Madone SLR at the Critérium du Dauphiné went live, the online community went nuts. The reactions ran the gamut from “that’s definitely a mad one” all the way to “at first I thought it was a joke, sadly it wasn’t.” There was a lot of speculation, but now we’ve finally got the first in-depth test results.

The 2023 Trek Madone SLR Disc is more than just a looker with its radical design and all-new IsoFlow system. The American brand promise a wide range of advantages and claim to have solved some of the issues of its predecessor. Trek have completely overhauled the existing IsoSpeed damping system, implemented several aero optimisations such as bigger aerodynamic compensation surfaces, according to the latest UCI regulations, and reduced the weight significantly. Besides the striking IsoFlow design, Trek obviously spec the bike with high-end components, including some from their in-house brand Bontrager, and offer deep customisation via the Project One configurator.

Trek IsoSpeed vs IsoFlow – An overview of the differences

Trek	IsoSpeed	IsoFlow
Availability	SLR Gen 6 | SL Gen 7 (from spring 2023)	SLR Gen 7
Mechanism	Damping element, seat post decoupled from the seat tube	Trapeze shaped cut out
Location	Integrated into the top tube	Between the seat stays, seat tube, and top tube
Adjustability	Yes, can be adjusted according to the rider weight	No, it changes depending on the extension of the seat post
Complexity & weight	Increased, weighing around 300 g more than the IsoFlow	Part of the frame construction

Improved aerodynamics of the 2023 Trek Madone SLR 9 eTap Gen 7

It’s not just thanks to the new IsoFlow system that the aerodynamics of the 2023 Trek Madone SLR Disc have been improved, but also via the cockpit and therefore the position of the rider. After all, the rider produces the most wind resistance by far: riding on flat terrain, as much as 75% of the total drag is caused by the wind resistance of the rider, from speeds of just 15 km/h. So, there are a lot of gains to be made by optimising the position of the rider. As such, the handlebar of the Madone has been designed specifically for this bike, bringing the rider into an aerodynamically optimised position.

The slightly flared drops should offer improved control over the bike while also optimising the airflow over the rider’s thighs in order to reduce drag. Even the water bottles and the front mech have been integrated into the frame design, and the enlarged bottom bracket area takes advantage of the latest UCI regulations to further improve aerodynamics, like on the new Cérvelo S5 or SCOTT Foil RC.

Trek have attempted to quantify the promised gains. Accordingly, the American brand claim to save 9.3 Watts with the bike’s improved aerodynamics, i.e. the new IsoFlow system, improved tube shapes and cockpit design (without the rider). The optimised rider position alone should save around 10 W, giving you total saving of 19 Watts at 45 km/h in the drops. All these figures are relative to the 6th generation Trek Madone.

Weight optimization – How much lighter is the 2023 Trek Madone SLR 9 eTap Gen 7?

As the predecessor, the 2023 Trek Madone SLR is made of OCLV 800, which is the highest grade carbon that Trek offer. The SLR 9 with the eTap groupset weighs in at just 7.36 kg in size 56, making the 2023 Madone SLR Disc the lightest Madone Disc on the market. In total, Trek say they’ve shaved off 300 g compared to the predecessor, which would be a significant weight reduction. However, the previous Trek Madone SLR 9 Disc Gen 6 we had on test tipped the scales at 7.63 kg in size 56, so the actual weight saving is quite a bit less at 230 g, and that’s compared to a bigger frame size.

Of course, a large part of the weight reduction is down to the new IsoFlow system. Despite all their efforts, however, the Trek Émonda SLR 9 (review here) remains the lightest bike in Trek’s portfolio, weighing in at just 6.86 kg, though the latest generation of the Madone is steadily closing the gap. Whether you stand to gain more from aero or weight optimisation is heavily dependent on the elevation profile of the route, of course. On the climbs, you’ll benefit the most from the lower weight of the Émonda – especially the rotating mass of its wheels. The Madone, on the other hand, can play to its strengths on flat stages and descents.

300 g lighter than its predecessor – the lightest Madone yet.

The 2023 Trek Madone SLR in detail and models variants

The 2023 Madone SLR Disc is available in 6 different models with prices ranging from € 8,199 to € 15,699. If none of the standard models meet your demands, you can let your creativity run wild and even adorn your bike with gold leaf in Trek’s Project One configurator. The new, 7th generation Trek Madone SLR is exclusively available with electronic groupsets. You can choose pretty much freely between SRAM and Shimano, though. From SRAM, Trek offer the Rival eTap AXS, Force eTap AXS and RED eTap AXS groupsets, or the corresponding 105 R7170, ULTEGRA R8170 Di2, or DURA-ACE R9270 Di2 options from Shimano. All the SRAM equipped models also come with an integrated power metre in the cranks. Only the SL models will be available with mechanical groupsets. The SL models will also continue to rely on the old, 6th generation Madone frame featuring the IsoSpeed system, and a different carbon layup. As such, the new IsoFlow technology is reserved for the SLR range for the time being.

Supplied in-house, the 25 mm Bontrager R4 tires keep the bike grounded. These are fitted to Bontrager Aeolus RSL wheels with a rim depth of 51 mm, which, unlike the R4 tires, are tubeless-ready. Before converting to a tubeless setup, therefore, you won’t just need tubeless valves and sealant, but also new tires. Trek recommend a maximum tire width of 28 mm, which they say should give you 6 mm clearance around the tires. If you want to make the most of this clearance and fit wider tires, it’s up to you to decide how far you want to risk pushing this limit. However, doing so isn’t officially Trek approved.

The seat post and handlebar are made especially for the 2023 Madone Disc. The seat posts are available in 4 different variants. Frame sizes 47 to 54 come with a short seat post whereas sizes 56 to 62 come with a long version. Adapting the seat post length according to the frame size is necessary since the seat mast is too short to offer a wide range of adjustability. By making the seat post clamp reversible, Trek were able to maximise the adjustment range, allowing you to adjust the saddle height by 70 mm with both the long and short seat post. Unlike our test bike, the seat post is colour matched, and it comes with 0 mm offset as standard, though there’s a 20 mm offset version available.

The cockpit of the 2023 Madone SLR Disc is made of one piece. Allowing you to dial in the fit, Trek offer 14 different sizes of the one-piece cockpit, which get specced according to the frame size or the customer’s request. If that still doesn’t let you get comfortable, you can fit any stem and handlebar combination you want, as long as it relies on a 31.8 mm clamp. All you need is a special headset cover.
The stock bike features a big 160 mm rotor up front and rear, making sure there’s enough braking power. Nothing has changed with regards to the cable routing, remaining almost completely hidden – you can only see a short section of the brake lines peeping out just before they reach the callipers.

As before, the 2023 Trek Madone SLR Disc is compatible with Trek’s Blendr range of lights. There’s a front Blendr mount included with the bike. Unfortunately, you’ll have to buy the mount for the Madone SLR seat post separately – we would have preferred if it was the other way around. After all, you want to be seen by other road users first and foremost. Of course, if you’re going to be training or riding day and night and in all conditions, it’s best to have both. Since it’s reliable and easy to maintain, Trek remain true to the T47 bottom bracket standard. That said, the 2023 Trek Madone SLR Disc is also compatible with 30 mm crank axles – you must just make sure that you’re using the correct bearings.

The geometry of the 2023 Trek Madone SLR Disc

As before, Trek have gone with their “moderate” H1.5 geometry for the 2023 Trek Madone SLR Disc, which sits between the more aggressive H1.0 geometry and the H2.0 variant that they use for their endurance road models. The rider gets put into an aerodynamic position predominantly via the handlebar. The bike will be available in Trek’s usual 7 sizes, ranging from 47 to 62 cm.

Size	47	50	52	54	56	58	60	62
Top tube	512 mm	521 mm	534 mm	543 mm	559 mm	574 mm	586 mm	598 mm
Head tube	100 mm	111 mm	121 mm	131 mm	151 mm	171 mm	191 mm	211 mm
Head angle	72,1°	72,1°	72,8°	73,0°	73,5°	73,8°	73,9°	73,9°
Seat angle	74,6°	74,6°	74,2°	73,7°	73,3°	73,0°	72,8°	72,5°
Chainstay	410 mm	410 mm	410 mm	410 mm	410 mm	411 mm	411 mm	412 mm
BB Drop	72 mm	72 mm	72 mm	70 mm	70 mm	68 mm	68 mm	68 mm
Stack	507 mm	521 mm	533 mm	541 mm	563 mm	581 mm	601 mm	620 mm
Reach	373 mm	378 mm	383 mm	386 mm	391 mm	396 mm	399 mm	403 mm

The 2023 Trek Madone SLR 9 eTap Gen 7 on the road – Our first ride review of the new IsoFlow aero machine

The 2023 Trek Madone SLR 9 eTap Gen 7 looks like it’s raring to go just standing there, looking like it’s in a continuous state of tension and striking a good balance between clean, simple lines and high-quality details – our high expectations of the bike were high.
Once aboard the bike, you can feel the flex and pleasant level of compliance offered by the IsoFlow system. While it isn’t adjustable, the amount of flex changes depending on how far you’ve got the seat post sticking out – 77.5 cm in our case. It does a good job of filtering out small bumps, and even bigger impacts get mitigated by the bike before being passed on to the rider. There’s nothing to stop you from taking on longer tours on rough asphalt and poorly maintained roads. The comfort offered by the rear end stands somewhat in contrast to the stiff front end, only providing a bit of compliance when you’re in the drops – if you hit corrugations with your hands on the hoods, you’ll feel your teeth rattle.

Cruising leisurely aboard the 2023 Trek Madone SLR 9 eTap Gen 7, you’ll quickly realise that that isn’t the bike’s forte. At slower speeds, the handling feels slightly nervous, and the front wheel tends to tip from side to side. This wasn’t an issue when winching our way up steep climbs, but it doesn’t instil you with confidence when rolling slowly up to a red traffic light as you wait for it to turn green. When get up out of the saddle and put the hammer down, however, the bike surges forward and begs for more. The stiff bottom bracket transfers your pedalling input with minimal losses, quickly propelling the bike up to cruising speed despite the deep and therefore relatively heavy 51 mm rims. Once you’re at your desired speed, the bike will hold that pace with ease, not least thanks to the ergonomically and aerodynamically shaped cockpit: the gentle back-sweep puts you in an aero position with your elbows tucked in while the flared drops offer plenty of control and a higher level of compliance. The rounded edges of the tops are pleasant to hold on to in case you feel like assuming a more upright position. Assume the aero position, though, and the 2023 Trek Madone SLR 9 eTap Gen 7 seems to crave speed, so much so that we feared running out of gears on flat terrain.

Once you’ve summited the peak and start heading downhill, the 2023 Trek Madone SLR 9 eTap Gen 7 really comes into its own. The handling feels planted and composed at high speeds, yet it remains responsive and precise enough for spontaneous corrections in the peloton or to swerve around a pothole that you didn’t see coming. Trek have struck an excellent balance with the bike’s handling at speed. The bike does get pushed sideways by crosswinds, but it does so evenly and remains easy to control. It doesn’t get jerked around and feel nervous at all! Only the tires tend to lose traction and slide out during hard braking manoeuvres on wet asphalt – we would have preferred a set of tubeless-ready 28 mm tires instead.

You can make the bike significantly more comfortable by fitting a pair of wider tires, though it’s an excellent all-rounder in the stock configuration, nonetheless. All in all, the 2023 Trek Madone SLR 9 eTap Gen 7 has become significantly more versatile: it’s become lighter and more aerodynamic, it’s a better climber and it’s less complex thanks to the new IsoFlow system, which is a boon for both home and pro mechanics. An (almost) complete all-rounder.

Who is the new 2023 Madone for?

Whether pro athlete or ambitious privateer, criterium or steep Alpine passes, the 2023 Madone Disc is aimed at those who have need for speed. If you know Trek, you will know that the SLR range isn’t aimed at the masses, but rather at pros and all those who dream of being one – assuming you’ve got the money. Still, the components make this aero bike a superb all-rounder for all those looking to save some Watts. If you prefer flying under the radar as you enjoy your training rides, the polarising design of the Madone clearly isn’t the right choice as other riders will try to quiz you about it wherever you go. That’s exactly what some riders want, so it all depends on the type of rider that you are. Want that race feeling, but far away from traffic and asphalt? Then check out our review of the 2023 Checkpoint SLR 7 with its integrated storage compartment (find the review here).

Tuning-Tipp: downsize for more comfort, due to the longer seat post extension | 28 mm tubeless tires

Our conclusion on the new 2023 Trek Madone SLR 9 eTap Gen 7

The updates made to the new 2023 Trek Madone SLR 9 eTap Gen 7 have made it significantly more versatile. It doesn’t just look damn fast; it is damn fast, too. And the handling remains responsive at high speeds without lacking in stability. The clever new IsoFlow system reduces the bike’s complexity while offering a similar level of compliance. As such, the new Trek Madone serves ambitious (hobby) racers well and has what it takes to get you on the podium.

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Words: Julian Schwede Photos: Mike Hunger