New Trek Madone SLR: Can a hole in the seat tube make it the fastest one yet?
The brand new Trek Madone comes with a revolutionary design, but retains the neat and powerful look of its previous iterations
It's been cycling's most known open secret for the last month. But now it's no longer a secret. The brand new 2022 Trek Madone SLR is finally here ahead of the Tour de France.
The new steed from the American brand was seen and widely photographed and filmed at the Critérium du Dauphiné in June. Team Trek-Segafredo was racing with the new bike but jokingly denying they were using it, fuelling the secret-not-really narrative.
The development of the new Madone, as former world champion Mads Pedersen has explained, had started only a few months after Trek launched the previous Madone in 2019. So Trek engineers asked their professional riders what could have been improved on that bike, and though the bike is still fast and smooth, they said it could still be lighter and quicker, while remaining something that could be raced every day. Not an easy task.
Isoflow
The Madone (the seventh iteration) will be remembered for its hole in the seat tube, placed where the seat and top tube meet. Yes, there's a hole in the frame. And if you think it's to improve aerodynamics, you're correct, although that's not the whole story. But let's not call it simply a hole: Trek's engineers spent a lot of time to make it happen, and the technology goes by the name Isoflow.
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Among Madone's previous technology that riders questioned the most, regarding efficiency and aerodynamics, was the Isospeed, Trek's system that decouples the seat tube from the top tube, allowing the seat tube to flex with the forces of the road. The system was initially used for the Domane but landed on the Madone in 2016 and gravel bikes more recently. Trek says that even though the new Madone is a tad stiffer and racier than before, without the flexing component of the Isospeed, they could still transfer the flex component into the frame and maintain the excellent ride feeling and the seat tube compliance.
The seat tube junction area of the bike is also where a lot of turbulence is generated by the airflow. That's why after computer modelling and wind tunnel testing, the new system was born as you see it now as their best solution to improve aerodynamics. Still, it ended up enhancing stiffness and comfort at the same time. The Isoflow, simply put, can accelerate the air coming from the head tube in the front.
Trek also points out that the Isoflow helped in reducing the overall weight of the bike and that it made the bike more compliant, meaning that the overall ride experience is perfectly balanced.
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Time and watt savings
Of course, the new aerodynamic development goes hand in hand with speed and time-saving claims. Trek first tested the Madone through CFP (Computational Fluid Dynamic), then in the wind tunnel along with a pedalling mannequin. And it can comfortably say that, compared to the previous Madone, the new one is a minute faster over an hour if you ride at 45kph (30 seconds coming from the rider's position and 30 from the bike itself). But it also says this saving will be proportionate at lower speeds: 59 second gain at 35kph and 58 seconds per hour at 25kph. This makes the new Madone the fastest road racing bike Trek has ever made.
The time saving is due to many watt-saving improvements (and a total of 19 watts at 45 km/h). Of these, 9.3 watts are encapsulated in the frame design, and the improved rider's position gives another 9.7 watts.
The bar and stem system
On top of the Isoflow, a significant advancement in aerodynamics is also courtesy of the bar and stem system. Not only did Trek come up with an improved shape of the aero cockpit (again, a result of CFD and wind tunnel testing), but it also opted for different measurements on the top and bottom of the bar to optimise the riders' position in the saddle.
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Most notably, the new system features a shallow reach and a different width between hoods and drops, with the width of the hood 3cm narrower than the drops. The resulting position looks like what riders are trying to achieve these days: a narrower and more TT-like position on the road bikes (but still UCI legal).
This position, says Trek. both improves ergonomics and aerodynamics by putting the rider in a different position on other bars. However, the new bar is incompatible with aero extensions, and Trek suggests not sizing it up. For example, if you ride a 40cm handlebar, you should still go with a 40cm drop width (or 37 top widths).
Tube shapes
Then there's a new tube-shape system that helped make the new Madone faster and lighter. The bike uses a new generation of Kammtail Virtual Foil tube shapes, which feature a truncated, square end that employs the advantages of airfoils to reduce weight but increase stiffness and perform better in crosswinds.
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One of the more characteristic tubes of the new Madone is the chunky down tube which ends up in a pretty tall bottom bracket. This also reduced the drag created by having two water bottles on the down and top tube. Bringing the down tube up to meet the bottom of the seat tube bottle resulted in reduced drag overall. 
In term of frame geometry, the new Madone comes with what Trek calls a H 1.5 overall score, which sits in between its more aggressive design (H1 being the most aggressive, for pros only) and H2 more relaxed. H1 1.5 makes it a good compromise for pros and keen weekend warriors alike.
Weight
In terms of weight, the new Madone stands as the lightest Madone disc Trek has ever produced, and it's almost 300 grams lighter than the previous Madone (though their lightest remains the Émonda, while the Domane is the more comfortable model for endurance and rougher terrains).
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The areas where weight was reduced the most were, once more, the Isoflow and the bar and stem combo – where half of the savings come from. Extra weight was also saved in the seat post area, thanks to a new seat post clamp solution that comes in two different lengths and two different offsets to serve different riders' height. The front derailleur can be removed to save extra weight, improve aerodynamics further, and allow for a 1x drivetrain option.
The final touch is also the use of the OCLV Carbon 800, Trek's patented carbon fibre process, that allowed it to reduce overall weight by using less material in certain places but maintaining stiffness through the high quality of the fibres and the use of more material in other areas.
The Madone now weighs 7.1kg in size 54 and between 7.4 and 8.0kg in size 56 depending on the groupset. It is only compatible with electronic drivetrains (all cables are integrated), and it's shipped with tubeless-ready wheels but fitted with inner tubes and rim strips.
Trek recommends a max tyre width of 28 mm. It uses flat-mount disc brakes (160mm max rotor size), T47 BB, and it's compatible with cranks with 30mm spindles (though they suggest checking with the crank manufacturer for a compatible T47 BB).
For those into customisation there’s good news too, as in the future the Madone SLR will be also be available in the Project One customisation option.
