TREK EM O ND A
Trek’s Emonda SLR 9 eTap Project One aims to maintain its flyweight roots with the latest in aerodynamics…
Warren Rossiter gets to grips with the revamp of the Trek’s specialist climber, the SLR 9 eTap Project One
When Trek introduced the first Emonda back in 2014 it completed the brand’s triple line-up of pro-level race bikes. Trek, like the rest of the pro-peloton providers, had a bike for every stage of major races. Trek’s Madone, introduced in 2003, was raced by Lance Armstrong. In 2012 Trek diversified with its first anagram of Madone: the Domane. This bike was designed to attack the cobbled classics - a comfort-orientated race bike to take on Specialized’s all-conquering Roubaix, Trek even secured classics specialist Fabian Cancellara to ride it in 2014. In the same year the Madone had morphed into a full-on aero-road bike but Trek knew that its climbing specialists required a lightweight bike for the highmountain stages of the grand tours and so the Emonda was born, a bike designed to be lightweight above all else.
BR AV E NE W WOR L D
Bike design and the requirements of the pro-riders has changed since 2017. Many teams saw aerodynamic gains from the likes of the Madone, (Specialized) Venge, (Merida) Reacto and (Cervelo) S5 as worth the extra weight (usually around half a kilo to as much as a kilo) over a race distance. But pro climbers still wanted light bikes and were having to make tough decisions on bike choice, which is why we’re now seeing classic lightweight bikes being reinvented with aerodynamics as a major consideration. The Emonda’s competition (Specialized Tarmac, Cannondale SuperSix EVO, BMC Teammachine, Giant TCR) all aim to combine aerodynamics with lightweight to bring the best of both worlds to a more rounded racing machine.
So too the Emonda has evolved from its origins to be more aerodynamic than any of its previous versions while keeping light weight in the equation. Trek says that for its pro-tour Trek Segafredo riders (who can choose any bike from the Trek stable) they expect them to choose the new Emonda on seven out of 10 race days. That’s not to say the Madone and Domane are redundant: the Domane is still the best choice for the classics and the Madone will out-perform the Emonda on flatter stages as the sprinter’s bike of choice.
The most expensive, range-topping SLR follows a whole new shape in both its frame and the tube shapes although it does retain the signature, slightly bowed top-tube shape common across all of Trek’s road bikes. The new frame and tube shapes came about from Trek’s goal to create a more aerodynamic bike in all conditions, including while ascending, while previous design goals were lightweight and sti ness alone.
IN TO T HE MOUN TA INS
When it comes to aerodynamics, testing and development has always focused on bikes riding on the flat, or at speeds very few of us could ever achieve.
In recent years, however, these ideas have been questioned. We first heard rumblings of dissent from Nathan Barry, chief aerodynamicist at rival brand Cannondale who purported the idea that air resistance acting on a rider comes in at far lower speeds than most had thought. Extensive research discovered that even at 15kph/9.3mph, half of the resistance on a rider is the air.
There has, however, always been a trade-o between weight and aero. Research has also shown that a lighter bike (compared to a full-on aero road bike, such as the Madone) will climb faster on more extreme, steeper slopes. Trek’s thinking behind the design of the SLR is to get the best of both worlds by keeping weight, along with drag, as low as possible.
Trek’s approach to all-round aerodynamics included benchmarking the new Emonda prototype against the previous generation (2018 model) by basing the data on the new bike by climbing some of world’s most famous climbs, starting out with the iconic Alpe D’Huez. The reasoning for this was to prove the concept that by adding more aerodynamics to the Emonda, which does add a little weight (though much less than the di erence between the 2018 Emonda and the Madone) would have a significant benefit. From the results on page 92 you can see that the new bike would ascend Alp D’Huez 15 seconds faster (with the same rider) or 21 seconds faster up the Stelvio. With races won and lost by smaller margins, Trek considers the new design to be a resounding success.
Trek claims that a cyclist weighing 70kg on an eight per cent grade riding at 350w of e ort would save 18 seconds over the previous model per hour; on the flat at the same power output that would rise to a minute an hour. Aside from serious professional athletes not many riders could hold that sort of output, but for us more average cyclists there will still be some gains.
THE GENTLE TOUCH
The second aspect of the new Emonda is the retention of the lightweight character that the model is famous for. This is the result of research and development into carbon fibres and new processes into the manufacture of the OCLV 800 series carbon, but Trek won’t reveal details.
OCLV (‘Optimum Compaction Low Void’) is Trek’s long-standing carbon manufacturing process. This particular process of moulding carbon is designed to compact the layers of carbon and resin tightly together to eliminate ‘voids’ in the construction that can weaken the structure. It also helps to minimise the amount of heavy resins needed in the construction.
WHEN IT COMES TO AERO DYNAMICS, TESTING AND
DEVELOPMENT HAS ALWAYS FOCUSED ON BIKES RIDING ON THE FLAT, OR AT SPEEDS VERY FEW OF US COULD EVER ACHIEVE. IN RECENT YEARS, HOWEVER, THESE IDEAS HAVE BEEN QUESTIONED ...
Trek remains tight-lipped about the details but it does reveal that the carbon fibre material is the lightest and strongest it’s ever used; the resin has changed and the way in which these come together and are arranged within the construction has evolved way beyond its current OCLV materials.
The numbers bear it out: by comparison the 2018 SLR frame weighed in at 640g at its lightest rim-brake configuration. The new frame weighs in at just 698g (unpainted, 56cm) and a similarly svelte fork at 365g (unpainted with 220mm of steerer). The previous Emonda’s fork weighed 345g (rim brake, unpainted). When you consider that the addition of disc-brake mounts, new larger-sized aerodynamic tube shapes and a new, threaded bottom bracket shell (the previous model used Trek’s standard press-fit BB90) then the extra 58g of weight looks like a huge achievement.
The lightweight chassis is combined with Bontrager’s new Aeolus RSL 37 wheels at just 1325g a pair and a raft of new lightweight components, all finished o with SRAM’s flagship Red AXS wireless groupset. Our 58cm test bike, finished in luxury Project One livery, tips the scales at an impressive 6.92kg, just 22g over the UCI’s legal limit and a few grams heavier than Giant’s new flagship TCR Advanced 0 (6.71kg including two bottle cages), and a few grams lighter than BMC’s latest aero-integrated Teammachine SLR01 TWO (7.09kg including two bottle cages).
W H AT ’S YOUR A NGLE?
The geometry of the new Emonda range is based around Trek’s H1.5 numbers – an evolution of the brand’s old H1 and H2 fits. H1 represented the full professional ready-to-race position and H2 the place that most of us non-professionals occupy. It’s a great balance between race and recreation but, make no mistake, this is a racing machine so it is aggressively positioned with a 73-degree seat angle and a steep 73.8-degree head. The wheelbase is very short for a disc-brake bike at 992mm and the reach (the horizontal distance between the centre of the bottom bracket to the centre of the head tube) of 396mm isn’t overly long. The 581mm stack (the vertical distance between the top of the head tube to the centre of the bottom bracket), however, is low and racy (all figures quoted are for a 58cm bike). In comparison to Giant’s TCR, it shares the same stack height for a comparable size and a reach, just 6mm shy of the TCR’s 402mm combined with a short trail figure of 57mm (the trail figure comes from a combination between headtube angle and the fork o set). This measure shows the tyre’s contact point ‘trailing’ behind the steering axis. A small measure of trail makes for a fast handling bike while more trail slows down the steering response. Cannondale’s SuperSix EVO by comparison has a 58mm trail making both fast-handling machines.
RANGE TOPPINGS
This SLR is Trek’s premium o ering with a £9700 price tag in its favour so the specification o ers nighon flawless performance; nevertheless, Trek hasn’t compromised. The groupset comes with a Red AXS Quarq D-Zero powermeter chainset (with a list price of £1070 on its own), Bontrager’s latest, lightest
(and priciest) wheels, carbon-railed saddle, luxurious tyres and the smartly designed one-piece cockpit in the form of the RSL VR-C. This cleverly combines a real aerodynamic advantage over a standard barstem setup without the headache of complex internal routing. Instead Bontrager has channels running on the underside of the bar and then internally through the head tube in a channel that sits forward of the headset and fork steerer. It makes maintenance simple and the bike easier to pack down for travel. As a pro-racer’s bike first and foremost, this is of paramount importance.
ALL ABOUT THE FEEL
As soon as you are aboard the Emonda it feels wonderfully alive and yet the solid sensation of the chassis on a bike this light inspires confidence and is exciting too. The sharp snap to the steering is in keeping with the bike’s nimble character, thanks to its short wheelbase and lack of any energy-sapping excess weight.
As you’d imagine it also makes for a rapidly accelerating bike that covers ground with impressive ease and is not hampered (as previous ultra-light bikes have been) by a lack of torsional rigidity under power. There’s no flexing between front and rear: just perfect tracking even under a high load cornering at speed.
Trek’s aero-testing and aero-climbing research shows significant gains from the improvements in design, but impressive wind tunnel and modelling derived numbers are one thing, what we’re interested in is how it rides. We love the feeling through the pedals of a bike that’s so wonderfully quick. The Emonda’s chassis is responsive without being overly rigid and the lightness translates into a fine balance between nimble handling and reassuring balance.
When it comes to ascending a bike with this little weight, particularly regarding the wheels which are shod with supple, high-cotton count handmade clincher tyres (not tubeless), it’s very impressive. You have SRAM’s superb Red AXS ensuring quick, smooth shifts across its 48/35 – 10-33 pairing. This is comparable to a traditional 52/36 with an 11-28 cassette – though you have both a lighter and harder gear at each end with SRAM’s X-Range 12-speed setup. The
SLR is not going to turn you into a polka-dot jerseywearing rider at the sight of the first col, but it does make climbing easier and you will feel, and gain, an advantage on serious ascents.
COMFORT COMPROMISE
Both the Domane and Madone come equipped with Trek’s road-bike suspension, IsoSpeed. This system
THE CHASSIS IS RESPONSIVE WITHOUT BEING
OVERLY RIGID AND THE LIGHTNESS MEANS NIMBLE HANDLING
uses a pivot, or decoupler, between the seat tube and top tube at the rear that allows the seat tube to flex over rough terrain providing vibration damping and superior comfort. The Domane also gets an IsoSpeed unit on the head tube, which allows the fork steerer freedom to flex, o ering comparable comfort up front. In comparison, the Emonda has always been Trek’s firmest riding bike and the same is true of this new machine where obsessive weight reduction and management has taken precedence over comfort.
Subsequently, the Emonda transfers a lot more of the road surface, so when riding over high-gravel content tarmac or chip-laden roads you do get some vibrations. Thankfully, it’s not wearing but it’s still not ideal. You certainly notice poor road surfaces more than on Cannondale’s EVO and Giant’s new TCR, although it is in line with the feel from BMC’s new Teammachine. In fact, we’d go so far as to say that the 2021 Emonda with its 25mm tyres rolls firmer than the 2018 incarnation as the specification on that bike included 28mm tyres for its final versions. All of the rivals mentioned above are running 25mm tyres as standard too.
The R4 320 thread-count tyres are wonderful on great road surfaces and zip along swiftly and grip well, but on the high-chip-stone tarmac mix common on our home test roads the SLR can start to feel somewhat choppy and chattery. The wonderfully ergonomic Aeolus RSL bar does a good job of easing highfrequency vibrations whether you’re in the drops or on the hoods, while the tactile, aero, yet ergonomic tops dressed with quality Bontrager bar tape also deserves praise in keeping your hands free from numbness.
The Aeolus Pro, Bontrager’s new short-saddle design is incredibly comfortable with quality padding in all the right places and a deep channel to avoid undue pressure where you don’t need it. Trek has done a wonderful job with getting the contact points just right, but we’d still like to see the specification reflect the road quality in the UK; that simply means 28mm tyres. We switched in a wheelset with 28mm Continental GP5000s and the ride was significantly smoother. The bike is designed to take up to 28mm tyres with plenty of room to spare (we measured a full 9mm each side of a 28mm tyre). With Trek’s Project One custom program you can specify your own tyre choice.
RACE DNA
The new SLR is everything a cutting-edge racing machine should be: sti and responsive with confident handling and very light. It boasts the best modern design and technology have to o er, aerodynamics, disc brakes and now it can add light weight into the equation. Bikes such as Cannondale’s SuperSix Evo, BMC’s Teammachine, Scott’s Addict and the TCR Advanced 0 showcase what the professionals will be riding now; in a few short years lightweight advancements like this will be found on bikes that we can all a ord.