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by James Huang
July 7, 2018
Photography by James Huang
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.
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.
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.
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.
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.
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.
We’ve seen this sort of paint used on other brands (such as Masi, who calls it “unicorn blood”), but Trek’s Prismatic Pearl is no less striking.
Is it silver? Green? Orange? Purple? Yes.
The Project One ICON Refliptive finish is meant to recall the old Klein bikes of yesteryear.
The down tube logo is reflective on this one, though, which not only helps with nighttime visibility, but is also just plain cool.
The Trek logo is also pleasantly subdued on this one.
The Brushed Liquid Metal option is elegant and subtle.
From a distance, the Brushed Liquid Metal finish looks like just a plain silver paint job. But when you look closer, you can see the brush lines that are applied by hand to make the bike look like it’s made of metal.
The Brushed Liquid Metal finish really lets the shape of the Madone SLR frame speak for itself.
Holy green! The Candy Emerald Green finish is incredibly rich and deep.
Team riders will be on the Chrome Tour finish, which uses pearlescent white paint and red chrome logos.
The Black Gold option in Trek’s new Project One ICON custom paint program clearly isn’t for riders who want to fly under the radar. This is about as showy as it gets.
The bike is fairly subdued when it’s cloudy, but once the sunlight hits it, the gold really comes out.
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.
Never has the aero road bike category been so hotly conteested with bikes that are not only fast, but far more usable for everyday riding than they used to be. The latest Madone is supposedly as speedy as the previous one in terms of aerodynamics, but also more comfortable.
Trek clearly isn’t shy about the logo on the new Madone.
With the UCI now finally making disc brakes fully legal, it’s now likely just a matter of time before they become the norm, rather than the exception.
Rather than try to completely hide the new IsoSpeed structure into the frame, Trek actually highlights it as part of the new bike’s design.
The slider can’t be adjusted on the fly, but changing the ride stiffness only requires loosening a single bolt.
This latest evolution of Trek’s fantastic IsoSpeed concept truly does deliver a smoother ride than previous Madones – or a stiffer one, should you so desire. The company says the tuning range should satisfy just about every preference.
The previous Trek Madone uses a complex dual seat tube design to accommodate the IsoSpeed functionality.
To minimize bouncing, there’s now a small eleastomeric friction damper built into the base of the pivot assembly.
The new Madone SLR may be slightly less complex to manufacture than before, but there’s still a lot more going on here relative to a conventional modular monocoque carbon fiber road frame.
One can only wonder how soon the new IsoSpeed design will find its way into Trek’s other road bike lines.
A pass-through is built into the boomerang to accommodate rim-brake bikes.
When all of the cosmetic covers are in place, the new seat cluster actually looks quite tidy.
Seat height adjustments are now performed with a 5mm hex wrench, which secures an internal wedge. I would have liked to see a snap-on rubber cover here, though.
As with Trek”s earlier no-cut seatmast designs, this one eliminates some of the hassles of truly integrated seatposts. And if you were really pressed for space inside a travel case, for example, you could theoretically remove the IsoSpeed boomerang altogether.
The handlebar clamp itself is aluminum, but there’s a cosmetic carbon composite cap bonded on to the top of it.
At least for now, Trek is only offering its popular VR bend for the Madone cockpit.
As before, the headset spacers are profiled to match, and are split so they can be added and removed without having to recable the entire bike.
The front of the cockpit once again includes an integrated mount for computers, lights, and cameras. Bontrager offers a number of Blendr accessories already, but anything based on the GoPro mounting standard will work. The single-mount plate is shown here, but there’s also a double plate if you want to run a computer and a light, for example.
The new bar features swept-back tops, which Trek claims are more ergonomic than the straight tops used on the previous Madone.
Trek has enlarged the openings on the underside of the stem to help ease the build process (a little).
Bar angle adjustment is physically limited to +/-5°.
The unique steerer tube shape has two flattened sides along with a central channel to accommodate derailleur and brake housings as necessary.
Trek did a great job with the previous Madone, but clearly it wasn’t good enough. Every note shown here represents some type of improvement identified internally by Trek.
Trek showed this concept a few years ago, and it’s interesting to see how similar the new Madone SLR is in terms of styling.
This is just a computer rendering, but essentially identical to the real thing. It looks better in person.
One thing is for sure: the new Trek Madone SLR is about as far from traditional in appearance as you can get while still satisfying UCI guidelines.
Is the new Trek Madone SLR fast? It sure sems that way. But is it subtle? Not exactly.
Even given the complexity of the new IsoSpeed design, Trek has still managed to build an admirably sleek and modern-looking structure around it.
At the rate aero road bikes are progressing in terms of traditional performance metrics like ride quality, weight, and stiffness, one can only wonder how soon they’ll outnumber round-tubed machines.
The frontal profile of the new Trek Madone SLR is particularly svelte, and made even more so by the omission of the rim brakes (and the associated flappy doors of the old version).
Trek supposedly designed the new Madone with water bottles in mind, although it’s hard to see how that would be given this sharp leading edge on the seat tube.
The straight break between the two colors on my test sample makes for a simple, yet impactful, look.
Trek uses its top-end 700-series OCLV carbon fiber blend for its flagship road racer, although it’s worth noting that the company quietly shut down its US production within the last couple of years. Every Trek bike is now made overseas.
The chainstays only look relatively slim in comparison to the monstrous down tube. It’s only when you compare them to the crankarm that you get a better sense of their height.
The chainstays are highly asymmetrical, too. And these 25c tires have an actual measurement of around 26.5mm on the wide Bontrager Aeolus XXX rims, so you can see how conservative Trek is being with its 28mm maximium official tire size.
The new front brake caliper operates on the same basic wedge-type design as the old one, but the wedge and rollers are not basically turned almost 90 degrees to make the package more compact.
There are still independent adjustments for pad position, arm position, and spring tension like on the previous Madone.
On rim-brake bikes, the front brake housing stop is built directly into the pass-through at the base of the steerer tube.
The new rear brake has slightly different shaping than the old one, but is basically the same in terms of function.
Shimano’s new handlebar-mounted Di2 interface has been very popular. No longer is it hidden away inside the down tube like on the previous Madone.
To help prevent frame damage in a crash, there’s a stop built into the headset assembly that limits how far the bars can be turned.
The latest Madone is once again compatible with Bontrager’s DuoTrap S wireless speed and cadence sensor.
Can’t stand Trek’s proprietary BB90 press-fit bottom bracket design? Sorry, folks, it’s still here.
The seatmast head is simple to adjust, with separate clamps for tilt and fore-aft position.
Hoses and wires are only very briefly visible on the new Trek Madone SLR.
Trek’s latest Madone SLR features a new chain catcher design, too, which is now adjustable from the top.
Cable guides for bikes with mechanical drivetrains are molded directly into the shell. Cable liners are definitely required.
The new Madone SLR will actually have two options for cleanly mounting rear lights. One attaches to the seatmast binder bolt hardware while the other one clips directly to the back of the seatmast head.
The Shimano Di2 battery and junction box are secured to the backside of this plate on the down tube, which also secures the rear brake hose to help keep it from rattling.
Where does the Madone go from here? We’ll have to wait a few years to see.
Trek is offering the new Madone SLR in a variety of complete builds, but says a surprising percentage of buyers just go through the Project One custom program instead.
The Trek Madone SLR 6 and SLR 6 Disc will be the least expensive on the inline Madone models, built with Shimano Ultegra mechanical drivetrains.
Trek will offer the women-specific version of the Madone SLR 6 Disc in a wide array of colors. The frameset is identical to the unisex version, but touch points are altered to supposedly provide a better fit.
The Trek Madone SLR 7 Disc WSD moves up to Shimano’s Ultegra Di2 groupset.
The unisex Trek Madone SLR 7 Disc is much the same as the women-specific version, save for a few minor component changes (and different color options).
Feeling a little more flush with cash, but still want to stick with a non-powered drivetrain? Trek answers the call with the Madone SLR 8 Disc, which is built with Shimano’s latest Dura-Ace mechanical groupset.
The Madone SLR 8 is possibly the lightest of the new Madone SLR options, featuring rim brakes and a Shimano Dura-Ace mechanical groupset.
The flagship model is the Madone SLR 9 Disc, built with either Shimano Dura-Ace Di2 or SRAM Red eTap, and Bontrager Aeolus XXX 6 carbon clinchers.
And finally, there’s the Madone SLR 9, offering rim brakes and Shimano’s Dura-Ace Di2 electronic drivetrain.