Wilier Triestina bills the Zero SLR as “the first ultralightweight racing frame with disc brakes and fully integrated cables.” While the exact point when a lightweight bike earns the “ultra” moniker is up for debate, a sub-7-kilogram build—a size medium with disc brakes weighs 6.795 kilograms (14.95 pounds)—is certainly deserving of the title in our book. One caveat is that that weight includes tubular ULT38 wheels, although quality clincher race wheels would still put you under 7 kilos.
Speaking of disc brakes, this frame is optimized for them, with asymmetrical fork blades that accommodate the uneven forces they generate. There is no rim-brake version available. This is a project bike for Wilier to meld its years of experience with all the latest technologies, including hydraulic Di2. It’s looking to the future, and rim brakes appear to be slowly fading from sight in bike-tech’s rearview mirror.
At under 800 grams, the Zero SLR frame sets a low weight for climbing. But it incorporates aerodynamics too. Truncated airfoil tube shapes help it target Strava segments, both on pancake-flat county-line sprints and shallow climbs. A new seat-post clamp, integrated to secure the truncated airfoil seat tube, is thin to keep the weight down but it also creates a narrow profile for enhanced aerodynamics. Additionally, the asymmetrical fork, which weighs in at a svelte 340 grams, has an increased distance between the fork blades and the wheel, which creates better airflow, a trick Wilier picked up from designing its Turbine time trial bike.
Wilier’s Zero.6 and Zero.7 models were already impressively light and responsive, but the SLR beats them both by quite a bit in terms of stiffness to weight. Wilier claims the SLR has a full 24-percent higher stiffness-to-weight ratio than the Zero.6—and better still compared to the Zero.7. Wilier achieves this by using high quality carbon called HUS-MOD. Integrated into the carbon layup is a liquid-crystal polymer—the same type of material used in bulletproof vests—to increase the frame’s strength and impact resistance while reducing road vibration. Fortunately, we stayed rubber-side down and never had to test the added impact resistance. And, like the fork, the rear triangle is asymmetrical, but in this case it is to better handle the uneven forces applied to the drive side.
Because this is an Italian bicycle, it would not feel right if it did not have the striking good looks to match. Luckily, that’s not a problem. Many companies are integrating aerodynamics into their lightweight climbing bikes, but few match the aesthetics of this bike. The cable routing through Wilier’s own Zero integrated carbon handlebar hides the cables for sleek lines. And the cable ends are hardly noticeable as they exit the frame for the brakes and derailleurs. With rounded edges and, at only 330 grams (100×42 size), the integrated handlebar is also beautifully sculpted in its own right. Plus, it neatly integrates a computer mount in a way that allows any GPS to be a continuation of the bike’s sleek aesthetics, not an afterthought.
Our only hang-up on the looks is the notch inside the main triangle housing the seat-post wedge. But its placement does provide an aero advantage. We were also a little saddened that our test bike did not come in the striking blue or velvety red paint jobs—not that it’s a disappointment to ride a bike like this in any color. As a consolation, the black version comes with a slight weight savings and still looks plenty beautiful—but, man, those blue and red colors turn heads!
Sometimes a bicycle’s maiden voyage at the Peloton Service Course is so enjoyable that we feel the urge to immediately pop open a bottle of Prosecco upon getting home. We can’t divulge how many times this has happened in our testing history, but the SLR is in rarified company.
Riding this bike feels a bit like waltzing with a professional dancer but having next to no experience yourself. Sure, the pro makes you better and you’re having a wonderful time, but deep down you know that you’re not letting her show off her unbridled talent. This bike is so lively uphill that it forces you out of the pedals to dance up climbs, until you come back to earth and remember that you’re no Pantani. But for brief moments you get to feel like a Pantani or a Contador anyway. Trying to be disappointed after riding this bike would be a tall order. You’ll be painfully aware of its potential and the biological limitations preventing you from fully engaging that potential. But that’s okay. It’s a fun ride even if you can’t quite take full advantage of it.
The same highly tuned handling that makes this bike excel in the mountains also makes it a bit twitchy on descents. Some riders dislike this feeling, but if you can tame this bike, it is capable of carving tight turns through technical switchbacks with ease. And once the road flattens back out, a strange thing happens. The very same bike that is twitchy downhill somehow offers some respite from the chatter of rough roads. No doubt the 28C Vittoria Corsa tubular tires have a hand in this feel, but the frame itself still offers an unexpected touch of compliance that will keep you feeling fresh for longer.
On flat roads, the SLR benefits nicely from the new aerotube shapes. It spins up to speed quickly and then holds onto that speed. It does not feel quite as fast as some other bikes in the aero lightweight race category that we have tried, but its sub-7-kilogram weight is noticeable when attacking—it takes off. In sprint efforts, the stiffness of this frame comes alive, just as it does in the mountains. All you have to do is think where to go and you’ll be transported there on demand.
As with many highly integrated bikes, adjustability is lacking. The bar/stem combo is the main culprit as there is no way to adjust the angle of the bars. Wilier’s stem spacers work very well for adjusting the height of the stem, but the total integration of cables makes it difficult to add or subtract much height after the cables are cut. The seat-post wedge can also be difficult to install. But at this price point, you are not paying for adjustability, you are paying for the absolute best. No one goes up to an F1 car and says, “Yeah, it’s the fastest car in the world but all the proprietary parts make it too difficult to work on.” All the best features, like total cable integration, require a little more maintenance.
Overall, the ride is race-tuned and punchy. It’s a climber’s dream and there is seemingly nothing it can’t do well. The Zero SLR easily sits among the best-handling race bikes we have tried.
€11,100 (approx. $12,500)
6.795kg/14.95 lbs (size M)
Dura-Ace Di2, 11–34 cassette, 50/34 Dura-Ace cranks, Wilier Zero Integrated Carbon Bar, Wilier Zero SLR Carbon, Selle Italia SLR Boost Kit Carbonio Superflow, Hydraulic Dura-Ace 9170 brakes (160mm/140mm rotors), Wilier ULT38 wheels, Vittoria Corsa 28C tubular tires.
This review originally appeared in issue 88.