2019 Trek Madone SLR first-ride review: Upping the ante

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The Trek Madone SLR takes all that was good with the previous Madone and made the new bike markedly better in seemingly every way. It’s now offered in both disc-brake and rim-brake variants, it’s supposedly just as aerodynamic as before (in both versions), the ride quality is more balanced and composed, and it even looks better with a shape that’s clearly derived from the predecessor, but yet cleaner and more refined.

Is the new Madone SLR the best aero road bike on the market? That question is impossible to answer with putting every other competitor through an exhaustive battery of objective and subjective tests, like the new Specialized Venge, Cannondale SystemSix, Giant Propel, and BMC Timemachine Road. But Trek sure seems to have made it harder for anyone else to claim the crown.

A clever new IsoSpeed design and a more balanced feel

While much of the attention surrounding the new Madone SLR revolves around its newly available disc brakes, it’s the new IsoSpeed system that should really be generating all the buzz.

But first, a primer on IsoSpeed for those of you who might not be entirely familiar with it: Instead of molding the seat tube, seatstays, and top tube together in a single structural unit as is usually the case, Trek “decouples” the seat tube from the rest of the frame, connecting it only with a pivot axle and a set of cartridge bearings. In this way, the seat tube is able to flex much more than usual when riding over rough terrain, and there’s a very significant improvement in ride quality as a result.

Although it’s a big deal that the Madone is offered with disc brakes for the first time, what’s arguably the bigger story is the new IsoSpeed seatmast design, which is now not only adjustable, but offers a broader tuning range than the old seat tube-based design ever could.

Pivot or not, though, deep-section seat tubes like what you typically find in an aero road bike aren’t exactly conducive to bending, so on the previous Madone, Trek used a novel dual seat tube design, where the integrated seatmast stepped down to a much smaller section at the IsoSpeed pivot. That smaller-diameter tube was then inserted into the outer aero-section seat tube, and bonded at the base. It definitely worked, but it wasn’t without its issues.

For one, the softness of the system was inversely related to the length of the tube, which is exactly what you don’t want; smaller bikes are usually piloted by shorter and lighter riders, not heavier ones. And unlike Trek’s Domane SLR endurance road bike, the system on the previous Madone wasn’t adjustable. It’s also worth noting that from a manufacturing standpoint, the double nested seat tube design wasn’t exactly easy to make.

And so for this new Madone SLR, Trek has shifted to a new L-shaped design, with the spring portion of the IsoSpeed system residing beneath the top tube. Since there’s more length to work with here, smaller bikes can now be set up from the factory to ride softer than bigger ones as they should, and because the unit is also now externally accessible, Trek was also able to give it the same adjustable stiffness functionality as on the Domane SLR.

According to Trek, the ride quality of earlier IsoSpeed designs on the Madone and Domane was still linked to frame size – and not in the way you’d want, as smaller frames would feel stiffer than bigger ones. This new boomerang arrangement takes care of that, and it’s also (slightly) easier to manufacture.

According to Trek, that adjustment range is pretty generous, too. The frame is 17% softer in its softest setting than the old Madone’s fixed setting for a given size, but up to 21% stiffer for riders who want a firmer feel. To combat unwanted bounciness, there’s even a small elastomer-based friction damper hidden inside the seat tube to help control the motion while pedalling.

Another complaint on the old Madone was its somewhat disjointed ride: while the rear end stayed impressively planted on rough roads, the front end was comparatively harsh and unyielding. Trek hasn’t added the Front IsoSpeed device on the new Madone SLR like it did for the Domane SLR, but the new cockpit supposedly offers a little more flex nonetheless to help balance things out (more on that in a bit).

As on the current Trek Domane SLR, a small slider effectively adjusts the length – and, therefore, the stiffness – of the carbon fiber leaf spring.

Disc-brake and rim-brake variants

As expected, Trek’s new aero road flagship finally adds disc brakes to the options list, along with the usual flat-mount caliper interfaces and 12mm-diameter front and rear thru-axles. Despite the decidedly non-aero brake hardware, though, Trek says that the new disc-brake Madone SLR posts virtually the same drag figures in the wind tunnel as the previous rim-brake Madone — a claim that’s all the more impressive considering that the predecessor was already widely regarded (and proven in third-party testing) to be among the most aerodynamic bikes on the road.

Trek was once openly resistant to the idea of offering disc brakes on its flagship road racing lineup, but that’s clearly changed with this new Madone SLR.

Trek hasn’t abandoned rim brakes just yet, though.

Rim brakes will be available throughout the entire Madone SLR line, and they’ve undergone some significant refinements. The rear caliper is mildly reshaped, but still blended into the seatstays, but the front caliper is virtually complete redesign.

Whereas the previous Madone had the front brake mounted to the front of the fork, the new Madone SLR flips the script and places the caliper on the back of the fork. It’s still a symmetrical roller-cam arrangement like before, but now the cable passes directly through the base of the steerer tube, and the wedge-and-roller assembly is turned almost 90° to create a more compact package. The old “vector wings” — better known as the spring-loaded “flappy doors” — that were once required for sufficient steering range are gone. There’s now a stop hidden inside the upper headset assembly to keep the bars from slamming into the top tube during a crash.

Trek hasn’t given up on rim brakes for the new Madone SLR, and in fact, they’ve only been further refined. Mounting the front caliper on the backside of the fork instead of the front, and routing the cable through the crown, yields a cleaner final package that also no longer requires those novel spring-loaded doors of the previous Madone.

I didn’t have a chance to sample the new rim brakes, but it’s at least encouraging to see that they offer the same amount of easy adjustability as before, including left and right pad location, left and right arm angle, and left and right arm tension, all of which can be accessed through ports on the cosmetic caliper cover.

The switch to disc brakes carries an additional benefit, too: more tire clearance.

Officially, the maximum allowable tire size is 25mm for the rim-brake version, but 28mm for the disc-brake one. However, it’s worth noting that Trek’s internal guidelines for tire clearance are more conservative than typical, requiring no less than 6mm of space between the tire and the closest point on the frame or fork; 4mm is more common (and technically mandated for stock bikes), and some companies flout those guidelines altogether when making claims of what will fit.

As such, it seems safe to say that a 28mm-wide tire will comfortably fit in the rim-brake Madone SLR, and 30mm-wide ones will fit in the disc-brake version, which should provide more than enough cush for most paved roads.

One geometry to rule them all, but still plenty of fit options

Trek previously offered each Madone size in two fit variants: the slightly more upright H2 version that was aimed at everyday riders, and the more aggressive H1 fit with its substantially lower, and slightly longer, front end. Trek has now switched to a single geometry called H1.5 for the Madone SLR, however.

As the name suggests, the H1.5 fit splits the difference between H1 and H2. It’s about 1.5cm taller than the former and about 1cm lower than the latter. According to Trek, a new -12° stem option will still replicate that H1 fit for its sponsored pro athletes and anyone else that can comfortably ride in that sort of posture, while the standard -7° stem will still offer a sportier fit than the old H2.

Gone are the old H1 and H2 fit variants in favor of a single H1.5 version.

Like before, there is no women-specific frame. There will be women-specific models, but those will only differ from the unisex versions in terms of components, component sizes, and colors.

Speaking of components, Trek has supplied the Madone SLR with an all-new two-piece aero cockpit that replaces the previous one-piece design and finally allows users to fine-tune the bar angle (by up to +/-5°). The flattened tops are also now swept back slightly (for better ergonomics, according to Trek), and there’s more wrist clearance while in the drops than before as well.

Perhaps best of all, the new two-piece configuration not only allows for the slightly softer ride quality already mentioned but also offers a wider range of width and length combinations than before. Stem length options are again limited to 90, 100, 110, 120, and 130mm, but in addition to those two -7° and -12° angles, there are now four bar widths instead of three: 38, 40, 42, and 44cm. Changing either the stem length or bar width later on will obviously be less expensive now, too.

Just as aero, and nearly as light

Trek says that its goal for the new Madone SLR was to “maintain aerodynamic drag performance of the current Madone (within 30g) across an averaged -12.5° to 12.5° yaw sweep.” In the end, the company claims a 3,216g of measured drag with the disc-brake Madone SLR vs. 3,202g on the old Madone — supposedly within the margin of error for the well-known Low Speed Wind Tunnel facility in San Diego, California.

Frame weights have gone up, but only very slightly. According to Trek, the current 56cm Madone 9 frame comes in at 1,053g, plus 376g for the matching fork. Claimed weight for the new rim-brake Madone SLR frame and fork are 1,112g and 378g, respectively, while the disc-brake version is slightly heavier still at 1,131g and 421g. Even so, Trek says the complete bike weights are identical for the rim-brake version — 7.1kg (15.65lb) for a 56cm size, without pedals. Claimed weight for the disc-brake Madone SLR is expectedly heavier, at 7.5kg (16.53lb), but supposedly still within the design targets.

The previous Madone never seemed all that inelegant or clumsy, but it does now in comparison to the new version, which is notably cleaner and sleeker looking.

Truly stunning custom paint options with Project One ICON

Naturally, Trek will once again offer the Madone through its Project One custom program, and there are apparently a lot of people who choose to go that route. According to Trek, fully half of all current Madones sold are Project One variants.

Project One buyers will be able to choose components, component sizes, and paint as usual, but new this year is the Project One ICON paint program, which includes six pre-configured color and design schemes that are clearly above and beyond the usual offerings.

There’s little point in wasting words describing what the new Project One ICON paint options look like. Instead, it’s far better to just show them to you.

Sampling the Madone SLR in cow town

Trek’s global headquarters of Waterloo, Wisconsin seems like an odd place to develop a world-class aero road bike like the new Madone SLR. There are seemingly more dairy cows here than people, no massive cols, and the rumbly pavement is poorly maintained. Winters here are long and punishing, and summer heat and humidity can sometimes make riding indoors in artificially cooled air oddly appealing.

Yet that environment still offers a surprisingly demanding setting. Harsh-riding bikes are downright punishing on the coarsely surfaced tarmac and annoyingly pronounced expansion joints, and mushy chassis bog down on the steep and punchy climbs that dot the dairy roads west of town, not to mention the unofficial sprint lines marked by the frequent town and county limit signs. The downhills may be short, but they’re similarly steep and fast, and coupled with the lumpy road surface, it’s easy to get in over your head.

The previous-generation model was widely regarded as a benchmark in the category, with independently verified best-in-class aerodynamic performance, a surprisingly accommodating ride quality thanks to Trek’s truly innovative IsoSpeed “decoupler” at the seat cluster, and one of the most highly integrated designs in the industry.

So is the new version really better? Actually, yes, it is.

The “Blue Mounds” area of Wisconsin is known for its wealth of paved roads, and general absence of traffic. The roads aren’t always the smoothest, however, which also makes them a good proving ground for a bike’s ride quality. Photo: Jeff Kenner / Trek Bicycle Corporation.

First and foremost, the improvement in ride quality is striking. The new IsoSpeed design is unquestionably smoother than the old one, but I didn’t notice a hint of bounciness in the saddle even with the IsoSpeed slider set in “full party mode.” Even better is the more controlled ride up front, which is less chattery and punishing than the one one-piece cockpit. It’s still nowhere near as pillowy as what the IsoSpeed offers out back, but it nevertheless makes for a more balanced feel front-to-back and a more planted sensation in general.

Remember what I said about those dairy roads being a little coarse and occasionally steep? One descent there dropped a paltry 70m (230ft) in elevation, and yet I still easily topped 80km/h (50mph) on the way down. Thankfully, the new Madone SLR felt perfectly at home in that moment, with neither the twisty corners nor the less-than-ideal pavement doing much of anything to upset its composure.

Those twisty corners also only served to confirm another of my favorite traits about the Madone: its impeccable handling. High-speed stability is truly confidence-inspiring, but yet it’s still plenty eager to change direction when necessary, and with little more than a subtle lean required to initiate the turn. Aside from the difference in head tube length, Trek changed nothing about the Madone’s frame geometry, and in this case, that’s a very good thing.

A bike with tubes this deep shouldn’t ride anywhere near as comfortably as the new Trek Madone SLR does on the road.

Bottom bracket stiffness feel about on-par with the old model, which is to say it’s very good and amply efficient. Front-triangle torsional stiffness seems to have improved slightly, though, which is a welcome change seeing as how I found the previous Madone to be a bit lacking in that regard.

Speaking of bottom brackets, Trek is soldiering on with its proprietary BB90 press-fit design. I didn’t experience any creaking either during my initial test ride in Wisconsin, or subsequent rides back on local roads in Colorado, but it’s still only been a few days so far. Even given the weight penalty, I still wish Trek had switched to a wide-format shell with more robust bearing options, such as PF86, T47, or even BB386EVO. But such is life.

I have no complaints so far about the new cockpit, however. The sweptback tops indeed feel more natural to hold (although I’d still prefer they were taped from the factory), and the additional wrist clearance while in the drops is most welcome.

Going along with the new frame design is an all-new aero carbon cockpit, whose two-piece configuration now finally allows for some bar angle adjustment.

But is the Madone SLR fast? And is it light? I can only objectively confirm the latter, as my 52cm sample weighed 7.70kg (16.98lb) without pedals, but with cages — not far off from the claimed figures, but still within the ballpark given the thick coats of paint (and paint is surprisingly heavy). As for speed, well, it certainly seems easier to maintain high speeds on the Madone SLR, which suggests that it’s just as aerodynamically slick as before.

However, what I found more interesting was the fact that I stopped thinking about it being a good aero road bike, and more about how it was a good road bike, period: capable, composed, planted, responsive. Those are all traits I value for any road bike, and the fact that companies have finally figured out how to make everything converge into a single machine that also happens to be aerodynamic is something that is long overdue.

Welcome to the new reality.


Disclaimer: Trek provided CyclingTips with airfare, accommodations, and loaner equipment to use during this event. Trek has also been an advertiser with CyclingTips.

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