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by Matt Wikstrom
May 17, 2018
Photography by Matt Wikstrom
TECH NEWS BROUGHT TO YOU BY BIKEEXCHANGE
Trek recently updated its lightweight racing chassis, the Émonda, with a variety of refinements for 2018, including the addition of a disc-brake version. We had a look at the Émonda SLR Disc when it was launched last year, so for this review, we follow that up with a closer look at the more affordable mid-range Émonda SL 6 Disc.
It has been almost four years since Trek launched the Émonda, the company’s lightest road chassis that not only yielded, at 4.65kg, the lightest production bike in the world, but according to Trek, the lightest range of road bikes as well. After devoting two-and-a-half years to development, Trek was never going to talk down what it had managed to achieve with the Émonda, which included some bold adjectives for the performance of the new bike.
The introduction of road disc brakes seems to have provided the main incentive for revisiting the design of the Émonda, but it also gave Trek’s engineers a good opportunity to build upon the experience gained from creating the first-generation Émonda (which supposedly included 300 physical prototypes). Computer modelling and finite element analysis was used to explore hundreds of refinements to identify only those that could provide a tangible improvement for the weight, stiffness, and compliance of the new frame. After that, physical prototypes were used to validate those predictions.
According to Trek’s figures, the company has managed to achieve all of these goals, however the magnitude of said improvements are modest, at best. The first-generation Émonda SLR frame and fork (56cm, H1 fit) weighed 690g and 280g, respectively, according to Trek, compared to 640g and 313g for the second-generation frame and fork. Overall frame stiffness has been increased by 11% with a head tube that is 1.7% stiffer and a bottom bracket that is 7.6% stouter, while vertical compliance has been improved by 1.9%.
The disc-brake version of the Émonda SLR mirrors the rim-brake version in many regards, however it is 62g heavier (frame, 665g; fork, 350g) and overall frame stiffness is down a little, offering a 9% improvement over the first-generation chassis. Clearly, Trek is working within the realm of marginal gains, but our roving reporter, Dave Everett, was able to notice a difference when he attended the launch of the bike last year, and concluded that the new bike was a tangible improvement.
While all attention was focussed on the new Émonda SLR Disc frameset at the launch last year, the more affordable SL version also received an overhaul, including the addition of a disc-brake version. Once again, Trek promised an increase in both frame stiffness and compliance coupled with a marginal weight saving: the first-generation SL frame weighed 1,050g with a 358g fork; the new SL frame weighs 1,091g with a 313g fork.
Unsurprisingly, the disc-brake version of the new Émonda SL is heavier than the rim-brake version with a claimed weight of 1,149g for the frame and 350g for the fork. Be that as it may, the Émonda SL in either guise is not going to woo weight-weenies, but it will have broader appeal since it is a lot cheaper than the SLR version.
A difference in carbon fibre accounts for much of the extra weight (and expense) of the Émonda SL frame — which is constructed from Trek’s 500 series fibre compared to the 700 series that serves the SLR — however there is also a difference in the moulds that are used, and hence, the final shape of the two frames.
Nevertheless, the SLR and SL frames share the same specifications that have been carried over from the first-generation Émonda, such as Trek’s proprietary BB90 bottom bracket, E2 tapered head tube, internal cable routing, and a semi-integrated seatpost. For the disc-brake version, there are flat mounts for the disc callipers and 12mm-diameter thru-axles for the wheels.
The geometry of the frame remains unchanged, too. Thus, the Émonda SL continues with Trek’s forgiving H2 fit that provides a taller head tube, however it is not as generous as the geometry for the Domane.
Frame sizes 50-54cm are partnered with a fork with 45mm of rake, while the larger sizes get a fork with 40mm of rake. Bottom bracket drop is 72-68mm, decreasing with frame size; chainstay length is 410-411mm, increasing with frame size.
It’s worth noting that the geometry of the Émonda SL is identical to the Émonda SLR and does not vary between the rim or disc-brake versions. In addition, it is almost identical to the current Madone, however the latter offers an extra 5mm of stack for each frame size.
The semi-integrated seatpost places a limitation on the maximum and minimum saddle height for any given frame size, which is detailed in Trek’s geometry charts for the Émonda SL. However, the maximum saddle height is based on a 175mm seat mast cap rather than the stock 135mm cap that ships with the bike, so buyers with long legs should pay attention to this when ordering and/or collecting the bike. Buyers that require less saddle setback can also opt for a cap with 5mm of offset rather than 20mm to help with their fit.
Trek has put together two builds for the new Émonda SL Disc frameset: the SL 7 and SL 6. However, the former (which features a Shimano Ultegra Di2 groupset and a Bontrager Aeolus Pro 3 carbon wheelset) is not available in all markets, such as Australia. By contrast, there are several builds for the rim-brake version of the Émonda SL on offer, providing buyers with a much wider range of options and pricepoints.
The Émonda SL 6 Disc features Shimano’s new Ultegra R8000 mechanical groupset (50/34T crankset, 11-28T cassette) with hydraulic disc brakes and 160mm rotors. The rest of the components come from Bontrager’s catalogue: Paradigm tubeless-ready alloy wheels with R2 Hard-Case Lite tyres (25C), Elite VR-C alloy bars, Pro alloy stem, and a Montrose Comp saddle with chromoly rails.
I’ve long been impressed by the quality of the presentation of Trek’s bikes, and the Émonda SL 6 Disc is another good example of this. The matte metallic gunmetal finish may strike some as conservative, but it’s not dull, and it sits well against the black components.
The 54cm sample sent for review weighed 7.94kg/17.5lb without pedals or bottle cages, which doesn’t do much to support the notion that the Émonda is a lightweight race bike. For those hoping for a lighter bike, they can opt for the SLR 6 Disc that promises a weight saving of 700-800g (depending on frame size), but it costs almost twice as much as the SL 6 Disc. Alternatively, the SL 6 with rim brakes provides almost the same kind of weight saving (600-700g) and actually costs less than the disc-brake version.
The asking price for the Émonda SL 6 Disc is AU$3,999/US$2,999/£2,650, which is fair given the quality of the build, but it won’t woo bargain hunters. For those looking for better value, the rim-brake version of the SL 6 sells for AU$3,499/US$2,699/£2,250. In both instances, Trek provides a lifetime warranty for the Émonda frame and a two-year warranty for the fork and all Bontrager components.
For more information on the Émonda SL 6 Disc and the rest of the Émonda range, visit Trek.
The Émonda has always fitted very nicely into Trek’s road catalogue, confidently staking out the middle ground between the aerodynamically-refined Madone and the rut-gobbling Domane. And while Trek went to extraordinary lengths to highlight the weight savings that the first-generation bike had to offer, they were limited to the high-end SLR frameset, so that everyday buyers opting for the SL version were missing out on the best that Trek had to offer.
With that said, a back-to-back comparison of the first-generation Émonda SLR 6 with the SL 6 (both of which featured rim brakes) demonstrated that the distinctions between the two versions of the frame were surprisingly modest. In fact, I found it difficult to appreciate any of the performance gains that the lighter SLR frameset might have provided simply because there was very little feedback from the bike.
The second-generation Émonda has reversed this to some degree, presumably due to the increase in the stiffness of the frame, and as a result, I found that the bike was more exciting to ride. An increase in feedback from the road adds life to the bike and gives it a race-oriented feel.
The bike was at its best on smooth bitumen. Rising out of the saddle, the stiffness about the bottom bracket was obvious, and I could enjoy some sense of responsiveness whenever I pressed on the pedals to accelerate. However, the overall weight of the bike held it back, so it won’t impress buyers looking for a svelte climbing rig.
It’s better to think of the SL 6 Disc as a bike for undulating courses. On this kind of terrain, the extra weight of the bike was less noticeable and I could enjoy the stiffness of the bike when attacking each short rise. Moreover, I was often struck by how sturdy and robust the bike felt, and sudden changes in speed really had no effect on its demeanour.
The second-generation Émonda SL 6 Disc may provide more feedback from the road, but that doesn’t mean that Trek has done away with the highly refined ride quality that defined the original Émonda. It’s still there, and at times, I was impressed with how well it worked to insulate me from unnecessary chatter. This was most obvious on groomed unpaved tracks where the Émonda SL 6 Disc provided a smooth, almost gentle ride, without robbing me of a sense of how the tyres were behaving on the dusty surface.
While the Émonda SL 6 Disc did an admirable job of soaking up vibration and chatter, it wasn’t nearly as adept at contending with shock, especially at the front end of the bike. Any kind of sharp hit from a bump, crack or hole was quite harsh, which was something that Dave Everett noticed at the launch of the Émonda SLR Disc last year. By contrast, the rear end of the bike was noticeably more compliant, so my backside never suffered the same kind of shock as my hands.
I was able to fit tyres up to 30mm wide on the Émonda SL 6 Disc without any risk of frame or fork rub. The larger tyres were able to reduce the shock of sudden impacts, however the front end of the bike was still too rigid for long stretches of unpaved terrain. Compared to a bike like Cannondale’s new Synapse or Canyon’s Endurace, the Emonda SL Disc Disc isn’t nearly as versatile, but then, riders interested in extra versatility are probably going to be looking at Trek’s Domane or the new do-it-all Checkpoint instead.
Thus, it’s best to consider the Émonda SL Disc as a pure road-going machine where tyre size and pressure can be used to satisfy the owner’s preferences for ride quality. I found myself vacillating between the stock 25c clinchers at 70psi and more supple 28c tyres at 60psi, but by the end of the review period, the narrower tyres seemed a slightly better match for the bike.
The stable and predictable handling that characterised the first-generation Émonda was still very much in evidence, which isn’t surprising given that no changes were made to the geometry of the second-generation frame. As such, the Émonda remains an inviting and well-mannered bike to ride. The steering tends towards slow, so the bike requires a little more effort when negotiating tight turns and technical descents, but I can’t see many riders struggling with this aspect of the Émonda’s handling.
Shimano’s new Ultegra R8000 groupset continues to shine, regardless of whether it is partnered with rim or disc brakes. The latter adds significantly to the weight of the bike, but that has more to do with the associated hardware (e.g. rotors and wheels) than the brakes. This is a handicap that continues to afflict road disc bikes in general, but for those looking for more braking confidence, it’s a necessary compromise.
Bontrager’s one-bolt saddle clamp promises to be easy to use, however the wedges that sink into the cap provide too much bite, so it is difficult make minor changes to the angle of the saddle. At the front end of the bike, Bontrager’s Elite VR-C handlebars offer more reach (85mm) than other compact shapes, which, when coupled with the generous length of the hoods of Shimano’s hydraulic brake levers, adds significantly to the overall reach of the cockpit. Swapping to a stem that was 10mm shorter was enough to address this issue for me.
It has been over 25 years since Trek introduced its first carbon fibre road bike frame and the amount of evolution that has taken place in that time is quite remarkable. One frame has slowly grown into three specialised offerings and the number of builds has blossomed to give shoppers an impressive range of bikes to choose from.
The Émonda may appear to be quite removed from Trek’s original OCLV road frame, but it still possesses the same kind of aura as a lightweight and exotic racing bike. This is certainly true for the Émonda SLR and some of the aspirational builds on offer, but the SL version is well within reach of many mid-level shoppers. It’s not going to dazzle buyers with a low weight like the SLR, but it is a confident road-going bike that promises to provide a tangible upgrade from an entry-level bike.
For those contemplating such an upgrade, the choice of brakes may create some consternation, however much of the controversy surrounding disc brakes has died down. Quite simply, discs have become a legitimate option for road bikes and are now future-proof to some degree, so buyers can decide the matter on the basis of appeal. In this regard, the Émonda may be a little late to the party, but the second-generation frameset gives shoppers both options to consider.
Tyre clearance is pretty generous with plenty of room for 28C tyres (25C tyres are shown).
The stock 25C tyre fits easily within the fork.
According to Trek, external routing reduces the weight of the fork.
The RT800 rotors build on Shimano’s Ice Tech concept by extending the alloy core to form cooling fins.
The rear brake hose and derailleur cables are all routed through the down tube of the frame.
Trek has dubbed its new internal cable routing system “Control Freak”.
The second generation Émonda provides a port for Trek’s DuoTrap speed and cadence sensor.
The new Ultegra front derailleur provides a plastic clip for keeping the end of the inner wire out of the way.
Bontrager’s Paradigm alloy wheelset is 23mm wide and tubeless ready.