Wilier's new Zero SLR is a disc brake road bike that combines a light weight with a high level of frame stiffness. With internal routing throughout, it's also one of the cleanest looking bikes of its kind.
Wilier took road.cc out to the launch of the new bike at its HQ in Rossano Veneto, northern Italy last month. I got two rides on the Zero SLR on successive days: one hilly ride of 2:20hrs and one of 3:20hrs which included climbing Monte Grappa – it's 1,775m high – and coming down the hairpins. In other words, I had a total of 5:40hrs on the bike over various types of terrain.
I rode a Zero SLR built up with a Shimano Dura-Ace Di2 groupset and non-standard Mavic wheels. All of the stock bikes in the range feature either Fulcrum or Wilier wheels (as in the photos).
As promised, the Zero SLR feels light in use, especially for a disc-equipped bike, but I'd say its overriding characteristic – the feature that you can't miss – is the high level of torsional stiffness. Get out of the saddle and sprint and the amount of sideways movement that you can detect through the centre of the frame is tiny.
The other time you really notice that stiffness is during out-of-the-saddle climbs. Hit the pedals hard on a steep section and everything feels solid underneath you, giving the impression that efficiency is high here.
We came down Monte Grappa on the shorter, steeper, more zig-zagging route, and the Zero SLR was a lot of fun on these roads. This is a bike that allows you to brake hard and late without any noticeable fork flex or judder, and you can lean it as far over as you dare in tight corners in the knowledge that you'll end up exactly where you want to go rather than simply in the general area. I have only good things to say about the Zero SLR's stiffness – a feature that's sometimes compromised when designers go in search of weight savings. The more power you put in the more you'll appreciate this.
The Zero SLR's other key characteristic is the smoothness of its ride. Wilier says that liquid crystal polymer woven into the frame improves vibration absorption. Maybe; it's hard to say based on just a couple of rides on unfamiliar roads.
The frame and fork are each able to take 28mm wide tyres and that's what I had fitted to my bike – Mavic's Yksion Pro USTs – although all of the options you can buy come with 25s. I'd certainly consider making the switch because I enjoyed a ride that was notably free of vibration – a lovely ride quality without much rattling even at high speed, and bear in mind that Italian roads don't tend to be any better maintained than British ones.
I was expecting some sketchy moments on the fastest downhill sections, maybe a bit of jumping about on the bumps and cracks, but I couldn't have been more wrong. The Zero SLR soaked up pretty much everything that came its way without worry. This is a bike you could happily ride all day long, and given half a chance I would have.
As you'd expect, the Zero SLR's geometry is highly performance orientated. It comes in six sizes from XS to XXL. I rode the XL model with a 54cm seat tube, 57.2cm effective top tube and a 17.2cm head tube. The head angle is 72.8° and the seat angle is 73°.
The stack on this size is 572mm while the reach is 397mm, giving a stack/reach of 1.44 – a typical race bike figure. Across all the sizes, the stack and reach measurements are never more than 2mm from those of Wilier's Cento10Pro Disc aero road bike. If you're after a relaxed endurance bike, this ain't it, although as usual you can adjust the front-end height with spacers.
You need to use two proprietary spacers between the top of the head tube and the one-piece Zero integrated carbon handlebar/stem, and then you have the option of fitting other 5mm and/or 10mm spacers. These spacers come in two parts that lock together with the brake hoses and gear cables running inside. They can be added and removed without the need to disconnect the brakes or derailleurs.
I only rode the XL size, of course, but Wilier says that the tube sections of the various options have been designed to offer consistent rigidity, handling and comfort.
"Specifically, during the design phase a different section of the main tubes was created depending on the size in order to increase the torsional stiffness and stability of the frame," says Wilier.
The cross section of the top tube, for example, measures from 38.13mm to 41.45mm depending on the frame size of the frame. Size-specific tubing isn't unique to Wilier – brands like Specialized and Trek do something similar – but it's not universal either.
You don't need me to tell you about the looks of the Zero SLR; you can judge them for yourself. I must say, though, that the clean design really appeals to me. Yes, external routing is easier when it comes to maintenance but the lack of any visible cables gives the Zero SLR a super-tidy appearance.
Many brands have been putting their efforts into aerodynamics over the past few years, but lightweight bikes like the Zero SLR still have a central place both in the pro peloton and among the bike buying public.
"The problem with a lot of aero bikes is the weight, and almost every race goes uphill a bit or a lot, so weight is a big thing," said Paris-Roubaix and Tour of Flanders winner Niki Terpstra, who was at the Zero SLR launch because his Total Direct Energie team ride Wilier bikes.
"You have to find the balance between stiffness, aerodynamics and weight. A big part of efficiency for me is stiffness, but adding 1kg to a bike for more stiffness is too much.
"I gave my preferences on the Cento10Air and Wilier took this information in the development of the new bike. I have a big history with a lot of different bikes and I have clear opinions about what's good and what's not good. It's really nice to be so close to the company and talking to the guy who's developing the bike.
"If you are sponsored by a bike brand that has two bikes, a light bike and an aero bike, it's also important that the geometry is the same. That allows you to switch between them easily."
Of course, that's not something that most of us need to worry about.
Overall initial impressions of the Wilier Zero SLR are positive. It's lightweight, stiff and reactive. It's also smooth, well behaved and easy to control. You're not offered a super-aero performance here, but if you're after a lightweight bike that packs in plenty of stiffness, this is a winner.
For more info on the Zero SLR go to www.wilier.com/global/zero-slr.
Mat has worked for loads of bike magazines over 20+ years, and been editor of 220 Triathlon and Cycling Plus. He's been road.cc technical editor for eight years, testing bikes, fettling the latest kit, and trying out the most up-to-the-minute clothing. We send him off around the world to get all the news from launches and shows too. He has won his category in Ironman UK 70.3 and finished on the podium in both marathons he has run. Mat is a Cambridge graduate who did a post-grad in magazine journalism, and he is a past winner of the Cycling Media Award for Specialist Online Writer.