2021 Trek Émonda SLR 9 eTap road bike first ride review – An aerodynamic climber

Trek’s flagship 2021 Émonda SLR 9 eTap model is the third generation of the American brand’s climbing specialist. With a completely new frame, a new Bontrager cockpit and wheels, the latest model also promises to deliver on flat terrain. Read on to find out whether Trek have mastered the balancing act between aerodynamics and light weight and how it compares to the Madone.

The Émonda has always been Trek’s quintessential road bike and the lightest model in their portfolio. The Émonda series has always developed in quantum leaps, taking Trek into a new era with every new generation: while the goal of the first generation was to fall below the 5 kg mark, the flagship model of the second generation already came in at just under 6.8 kg, including disc brakes. Trek were yet to include features such as internal cable routing, aerodynamic optimisation or increased tire clearance. That’s all about to change with the brand new, 2021 Émonda SLR 9 eTap, which was developed from the ground up in close cooperation with Trek’s in-house pro racing team. The briefing of Trek-Segafredo was to fill the gap that had opened up between the lightweight Émonda and the aero optimised Madone! A lightweight, aerodynamic bike that combines the best of both extremes, making it a high-performance all-rounder. While the advantages of aerodynamic bikes are obvious, it was extremely important for the team to meet the UCI weight limit of 6.8 kg. For top-performing athletes in the pro peloton, this is an entirely legitimate and important objective as they’ve already optimised their own weight to the maximum and races are often won or lost depending on the riders’ power to weight ratio.

The concept of the Trek Émonda frame

The latest generation Émonda is as light as Trek’s current know-how was able to make it while keeping the design aerodynamically optimised. Heavily influencing the bike’s development was the climb to Alpe d’Huez with its 21 hairpin bends, 1,120 meters of altitude over 13.8 kilometres and an average gradient of 8.1%. As you can imagine, weight played a crucial role. If aerodynamics were the only issue, the Émonda would have ended up looking just like the Madone. According to Trek, the latter will still be faster when it comes to wind resistance on flat terrain. However, the size 56 Madone weighs 7.63 kg, considerably more than the size 58 Émonda SLR, which comes in at just 6.86 kg. In contrast to the Madone, the aerodynamic optimisation of the new Émonda didn’t concentrate on the effect of high-speed wind hitting the bike head-on, but rather on the type of turbulent winds and gusts that you’re likely to encounter while climbing alpine passes such as Alpe d ‘Huez. This is referred to as slow or unsteady aerodynamics, which places a higher emphasis on constantly changing wind directions and rider positions at slow to medium speeds. Of course, the tube shapes and aerodynamic details developed in this way should also offer advantages over traditional round tube designs at high speeds, though not quite at the same level as a pure-bred aero bike such as the Madone. If you compare the difference in cross-sections of the tubes between the 2018 Émonda and the latest generation model, you can clearly see how aerodynamic optimisation affects the design of the bike.

In order to achieve the optimal balance between aerodynamics and weight, Trek rely on a new carbon technology called OCLV 800. Developing this new proprietary composite was a necessary step in achieving their goal since aerodynamically shaped tubes are typically heavier and less stiff than round tubes. Previously, OCLV 700 was Trek’s best performing carbon composite. According to Trek, when comparing OCLV 700 and 800, they were able to make the frame 60 g lighter, all else being equal. Considering the raw frame weight of 698 g for the SLR model (incl. derailleur hanger), that’s a saving of close to 10%. The new wonder material is reserved exclusively for the SLR models while the Émonda SL range will rely on Trek’s OCLV 500 grade composite. This results in almost double the raw frame weight, bringing it up to 1,140 g (incl. derailleur hanger). Like all of Trek’s road bikes, the new Émonda is approved for a rider weight of up to 125 kg. Trek also approve the use of the Émonda on a home trainer. Unfortunately, they couldn’t tell us whether the bike’s weight and aerodynamic optimisation would also have a positive effect on your results in a race on Zwift. 😉

The latest design of the Émonda is optimised for 25 mm wide tires with a maximum clearance of up to 700 x 28C. This includes the prescribed 4 mm of clearance per side plus an additional 2 mm tolerance. In practice, this means that you should be able to fit slightly wider tires, depending on the rim and tire combination. For the bottom bracket, Trek rely the T47 standard, which we first saw on Trek’s new Crockett cyclocross bike and is likely to feature on all future models. Besides being compatible with 24 and 30 mm axles, Trek see further advantages in the oversized bottom bracket housing as it provides added torsional rigidity. The frame set doesn’t only eschew with mounting points for mudguards but also Trek’s proprietary IsoSpeed system, as featured on the Madone and Trek Domane to much acclaim for the comfort that it adds. Even the dropped chainstays as you’ll often see on modern road bikes have had to give way to weight optimisation and maximum performance. Similar to the GIANT TCR Advanced SL 0 Disc or the OPEN MIN.D. Trek have integrated the seat post and seat cap, though with a comparatively generous adjustment range of 60 mm. Cable routing is internal throughout. The Émonda is compatible with all current electronic and mechanical groupsets as well as two-by drivetrains with a maximum chainring size of 53/39 t and one-by drivetrains with a maximum chainring of 50 t. It is disc brake specific only, whereby customers can choose between 140 or 160 mm rotors on the rear and the front is exclusively compatible with 160 mm rotors. Other features rounding off the frameset include the 100×12 mm thru-axle standard up front and 142×12 mm at the rear as well as the option of integrating Bontrager’s DuoTrap sensor into the chainstay.

However, Trek didn’t focus solely on optimising the frame but rather considered the bike as a whole as they developed the new Émonda. They invested heavily in their cooperation with the in-house brand Bontrager to develop a coherent overall concept, especially with regards to the cockpit and wheels.

Bontrager’s Aeolus RSL one-piece cockpit

The one-piece Bontrager Aeolus RSL cockpit made of OCLV carbon was designed specifically for the Émonda SLR and is reserved exclusively for the flagship models, while the SL models have to make do with a conventional stem and handlebar. We were particularly impressed with the way the included Blendr bracket for your GPS device and light attaches seamlessly to the handlebar. Even the cable routing is neat. Instead of routing the cables through the handlebar, they are guided along a channel in the bottom of the bar and stem and then enter the frame via a specially designed spacer, as on the ROSE REVEAL. This makes maintenance and replacements a whole lot easier. The Aeolus RSL cockpit is optimised for eTap (AXS) and Di2 groupsets and relies on the conventional 1 ⅛” steerer tube diameter, making it cross-compatible with other bikes. It’s equally compatible with mechanical shifters. However, the housing of your shifter cable could protrude slightly from the channel for the cables. The cockpit comes with a stem angle of -7°, a reach of 100 mm and a drop of 124 mm. You’ll be able to use conventional spacers on either side of the stem in order to set your desired cockpit height without having to shorten the steerer tube. On top of that, the cockpit is claimed to be 7 watts more efficient than its predecessor and is approx. 160 g lighter than the two-piece, integrated cockpit featured on the Trek Madone. See the table below for the available cockpit configurations (options vary depending on the market).

Dimensions (handlebar width x stem length in mm)	Weight (manufacturer’s spec in g)
440 X 120	295
440 X 110	289
440 X 100	290
420 X 120	290
420 X 110	286
420 X 100	285
420 X 90	280
400 X 110	282
400 X 100	280
400 X 90	274
400 X 80	274
380 X 100	276
380 X 90	274
380 X 80	272

New Bontrager Aeolus wheels on the 2021 Trek Émonda

In addition to the brand new cockpit, Trek present a new range of Aeolus wheels. The carbon wheels are available in three versions: RSL, Pro and Elite. All models are designed for clincher tires, tubeless-ready and exclusively for disc brakes with 24 spoke holes, centerlock rotor mounts, 12 mm thru-axles front and rear and no weight limit. The freehubs are compatible with Shimano 10/11-speed and SRAM 10/11-speed cassettes across the range, whereby 12-speed freehubs will be sold separately. All of Bontrager’s products come with the so-called Unconditional Bontrager Guarantee. See the table below for all the details at a glance.

Modell	Aeolus RSL 37 TLR Disc	Aeolus Pro 37 TLR Disc	Aeolus Elite 35 TLR Disc	Aeolus Elite 50 TLR Disc
Rim depth in mm	37	37	35	50
Rim width in mm	28	28	27	28
Internal width in mm	21	21	19	19
Weight per set (manufacturer’s spec in g)	1,325	1,505	1,665	1,730
Hubs	DT Swiss 240s	DT Swiss 350	Bontrager	Bontrager
Freehub	DT Swiss Ratchet EXP with 36 engagement points	DT Swiss Ratchet freehub with 18 engagement points	24 engagement points and 3 pawl mechanism	24 engagement points and 3 pawl mechanism
Price per set	€ 2,399.98	€ 1,299.98	€ 899.98	€ 899.98

The concept behind the Aeolus RSL 37 TLR disc wheels as featured on our test bike is en par with that of the Émonda: lightweight with good aerodynamic performance.

Project One for the Émonda

Project One has long been the go-to for all Trek enthusiasts who want something a little more special than the standard paint jobs and spec, never failing to deliver some truly jaw-dropping creations! Included are three new ICON paint jobs, Amplified Alchemy, Holographic Diamond, and Gold Flake (including real 24k gold), as well as the new KOM signature series. Besides the pre-configured ICON paint jobs, Project One allows customers to choose any colour combination from 49 different shades. In terms of componentry, you can take your pick of any component that Trek’s portfolio offers. If that’s not enough, we recommend taking a closer look at Project One Ultimate. Here, one of Trek’s own designers will help you realise your dream build with a professional custom paint job and every conceivable componentry spec. Price? Available on request.

Trek Émonda SLR 9 eTap 2021 – geometry and spec

Unlike the predecessor, Trek have done away with the two different geometry options, H1 (aggressive sitting position) and H2 (more relaxed sitting position), designing the new Émonda around H1.5 geometry. This should offer a good balance between aggressiveness and everyday suitability. Trek also refrain from gender-specific models, offering all frame sizes for both women and men. Instead, the stem, crank and handlebar are adjusted to suit smaller riders. In terms of fit and geometry, the Émonda is heavily based on the Madone aero bike.

Size	47	50	52	54	56	58	60	62
Seat tube length	424 mm	453 mm	483 mm	496 mm	525 mm	553 mm	573 mm	593 mm
Seat tube angle	74.6°	74.6°	74.2°	73.7°	73.3°	73.0°	72.8°	72.5°
Headtube length	100 mm	111 mm	121 mm	131 mm	151 mm	171 mm	191 mm	211 mm
Headtube angle	72.1°	72.1°	72.8°	73.0°	73.5°	73.8°	73.9°	73.9°
BB Drop	72 mm	72 mm	72 mm	70 mm	70 mm	68 mm	68 mm	68 mm
Chainstay length	410 mm	410 mm	410 mm	410 mm	410 mm	411 mm	411 mm	412 mm
Wheelbase	972 mm	974 mm	977 mm	981 mm	983 mm	992 mm	1,001 mm	1,010 mm
Reach	373 mm	378 mm	383 mm	386 mm	391 mm	396 mm	399 mm	403 mm
Stack	507 mm	521 mm	533 mm	541 mm	563 mm	581 mm	601 mm	620 mm

Depending on the frame size, the integrated seat post can be combined with two seat caps of different lengths. For sizes 47 to 54, you get a 135 mm long cap. The frame sizes 56 to 62 come with a 175 mm cap. Both caps are available with 5 or 20 mm offset, to allow you to find the optimal fit. The adjustment range of the seat post cap is 60 mm for both variants.

The flagship model that we tested came with a 2×12 SRAM RED eTap AXS groupset (click for review), including an integrated Quarq power meter, priced at € 10,999 and weighing in at just 6.86 kg in size 58. The spec list at a glance:

Groupset SRAM RED eTap AXS, 2 × 12, 48–35T
Cassette SRAM RED 10–33T
Brakes SRAM RED eTap AXS 160/160 mm
Wheels Bontrager Aeolus RSL 37 TLR Disc
Tires Bontrager R4 320, 700 x 25C
Seat post Bontrager carbon integrated, 20 mm offset
Handlebar Bontrager Aeolus RSL Integrated, OCLV Carbon, 440 mm
Stem Bontrager Aeolus RSL Integrated, OCLV Carbon, 110 mm
Weight 6.86 kg in size 58
Price 10.999 €
Availability now at official dealers

Trek Émonda first ride review

On our first ride, the Émonda delivered a convincing performance with extremely light-footed acceleration. No matter whether you’re exiting a corner, from a standstill or on an incline: the slightest bit of pressure on the pedals is immediately converted into forward propulsion. The surprising thing is not just how fast the Trek accelerates in every situation, but how efficiently it is able to maintain its speed on flat terrain or on ascents with a gradient of 1-2%. Speed all-rounder? Check!

The Trek doesn’t hide its competitive genes with regards to handling either, responding to the rider’s input with extreme precision. For experienced pilots, this results in handling that allows you to navigate tight corners even at high speeds. However, this also means that beginners should approach the Trek’s direct and precise handling with caution. It’s like a road-legal Formula 1 car and it needs to be handled accordingly. However, all this doesn’t mean that it’s difficult to keep the Trek going in a straight line. The geometry allows you to hold a straight line without any feeling nervousness or like you’ll get a speed wobble, successfully combining agility and composure.

As with the handling, you have to remind yourself of the type of bike you’re dealing with when considering comfort. The vertical compliance of the frameset is limited due to its aggressive nature, offering limited comfort on extended rides. The Émonda is not uncomfortable per se since it offers a pleasant degree of vibration damping. However, bigger bumps are passed on to the rider unfiltered. The more competitive riders amongst us will enjoy the feedback that you get from the ground, while those who prefer just cruising will miss the IsoSpeed damping system. Just like handling and comfort, the riding position screams pro-peloton and is aggressively stretched. Due to the combination of an integrated seat post and seat cap, it is important to go for a bike fitting before deciding which size to buy and make sure that you’ll be able to get comfortable. Although the adjustment range is comparatively big, riders with long legs and a short torso might reach the limits of what’s feasible due to the bike’s design.

How does the Émonda compare to the Madone

Èmonda or Madone? This is a question that not only the professionals will have to ask themselves in future races. As expected, the Émonda clearly has the edge in mountainous terrain, when sprinting up steep inclines and winding up endless climbs. Even on the descents, the razor-sharp handling and fast acceleration out of the corners put it far ahead of the Madone. On flat terrain, the Èmonda comes in at a very close second to the Madone as it is unaffected by changing wind conditions and crosswinds, delivering an equally convincing performance here. Even if it is slightly “slower” than the more aerodynamic Madone when studied in a laboratory, it has some clear advantages over the Madone in certain scenarios.

The Madone is perfectly equipped for everything from hilly to flat terrain. If you’re not racing against the clock on the climbs but simply trying to defeat your inner bastard, you can also tackle those mountain passes on the Madone. It is lightning-fast on flat terrain, but its oversized tube shapes and deep rims also make it very sensitive to crosswinds. In terms of comfort, the Madone is clearly superior: the IsoSpeed damping system doesn’t affect efficiency while taking the horror out of bad roads and is a huge plus on long rides. It allows you to go on long rides in a relaxed fashion without having to make an appointment with the physiotherapist when you get home.

Our conclusion on the 2021 Trek Émonda SLR 9 eTap

Trek’s 2021 Èmonda SLR 9 eTap is a speed-seeking all-rounder with super quick acceleration and razor-sharp handling in every situation. Anyone looking for a bike to take to the races or with a need for speed on their flat-out after-work ride will find it here. If you enjoy long all-day rides, you’ll find more versatile alternatives in the Madone or the Domane, which are much more comfortable. The Émonda was built with the aim of conquering Alp d’Huez’s 21 hairpin bends as quickly as possible and that’s exactly what it is ready for!

For more information about the Èmonda visit trekbikes.com. If you want to know more about the latest Bontrager products check bontrager.com.

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Words & Photos: Benjamin Topf