Giant Defy Advanced SL 0 review

When this bike was released, the UCI had just annouced that disc brakes would enter the pro peloton in 2017 - although after an accident a Paris-Roubaix it was withdrawn. That said, it's looking strongly like the UCI will reintoruce it so it means, potentially, that in the great brake war of the early 21st century, disc brakes have been declared the winner. For some this is an affront to tradition that will eradicate a century-old standard for no other reason than financial gain for the manufacturers. The Giant Defy Advanced SL 0, though, seems to suggest that the revolution may be painless, as well as televised.

Cabling - Giant has tried to integrate hydraulic cabling into the build, but the front brake cable still relies on zip ties rather than internal cabling, albeit partially concealed by the fork leg.

While I have my own doubts about the move, the bike industry is generally awash with excitement about disc brakes, welcoming the improved braking performance and the potential to re-examine the basic principles of the wheel. There’s no doubting the stopping performance of disc brakes, but so far we’ve seen few other benefits. Giant, however, has committed fully to the new technology, and has converted its entire range of endurance carbon bikes – the Defy – to disc brakes. With the Defy being a highly celebrated endurance platform, I was keen to see what the redevelopment has added (or taken away) from the bike.

Arresting development

The Defy isn’t a bike that I would expect to sit at the top of my favourites list. It has a relaxed, compact geometry, comfortable ride and weighty discs – the spec sheet seems to contradict my impulses to go as quickly as possible all of the time. It was to my great surprise, then, that I found the Defy to be one of the most fundamentally fun and likeable bikes I’ve ever ridden.

The Defy makes few claims to high speeds or aero trickery, but it gives every bit of the sensation of being a fast bike. It picks up speed remarkably well, and offers that rare, fast-paced rumble through its carbon chassis without ever compromising on comfort. Handling and acceleration both give the impression of a racy set-up, and I never found myself backing away from an opportunity to sprint. It seemed immensely stiff, while still flexing where it needed to. But it’s not its speed that makes the Defy great – rather its all-road appeal.

Reinforced rear - The rear end of the Defy has been only mildly reinforced to accomodate the discs, as it was already supremely stiff. The top tube, seat tube and seatmast all use D-shaped tubes, which Giant argues are better in terms of flex.

One of my rides took me to the back roads of Dorset, where single track became farm track became mud track, and yet I never found the ride quality compromised. The Giant offered a tactile response, yet was forgiving enough to take on a surprising variety of road surfaces and still perform every bit like a road bike should. While the cabling and discs seemed noisy over bumps, only a fraction of the shock was ever transmitted to my hands or backside. At times the front end did seem a little robust, however, possibly as a consequence of the beefier build necessary to accommodate the discs. But the Defy strikes a rare balance of a lightweight, stiff ride that is also forgiving when the asphalt turns nasty.

Frame

One key component in striking that balance is the use of an integrated seatpost, a feature that is becoming increasingly unpopular because it can make travelling with the bike tricky and harm resale value. The benefit, though, is that the flex of the frame, seatpost and riders, can be designed as an entire system. ‘By running an ISP we’re actually able to make a much lighter and more compliant frame,’ says Jon Swanson, Giant’s global category manager. ‘We’ve also found that it actually makes a torsionally stiffer frame because you’re not interrupting the flow of the carbon – it’s all one unit.’

Wheels - The Zipp Firecrest wheelset works particularly well with the frame, lowering overall weight and remaining impressively stiff. An odd feature, though, is the use of TRP rotors with the Shimano hydraulic braking system.

The weight-saving properties of the ISP may be the most impressive aspect, though, as the claimed frame weight of 890g includes the seatpost, potentially saving nearly 200g. With that in mind, the Defy is in super-light territory, despite being equipped for disc brakes. Accordingly, I found myself eagerly attacking 25% inclines, helped considerably by the compact gearing. But while speeding up climbs was great, it was slowing down on the descent where the bike really shone. 

Disc brakes

A big part of the charm of the bike (I’m reluctant to say) was the astounding performance of the disc brakes. On a Saturday morning ride in the dry, I can’t say I noticed much difference in the performance of the brakes over a well-maintained set of callipers on decent carbon rims. But in the wet or on rough muddy tracks or gravel, the discs really did change the game. Giant has clearly done a fine job of harnessing the power of the discs, and there was no shudder or harshness when braking, as I’ve seen on other bikes. The level of control and modulation meant I could roll down 20% muddy inclines without fear of losing control or locking a wheel.

The details - Thanks to Giant's own-brand finishing kit, the contact points of the bike do an excellent job of cushioning any disturbance to the rider. The beefy stem was also a welcome addition. Despite looking like Cav or Kittel's sprint setup, the SLR stem and handlebar were efficient while remaining comfortable over rough terrain. 'We moved to a larger steerer tube diameter [1.5-1.25" tapered] a year ago that increased the stiffness of the front end,' says Jon Swanson from Giant. 'But whenever you stiffen one piece the flex has to go somewhere, so what we were finding was that the stem became a bit of a weak link. So we counteracted that by increasing its stiffness and size.'

The disc brakes do come with some disadvantages, though. At times, despite generally feeling smooth, the brakes can be too powerful, and there is a risk of skidding when panic braking in situations – such as a car pulling out. I also felt that when feathering the brakes in sharp turns, the power of the rear disc brake seemed to pull the wheel out from under me. Then there’s the weight issue. With the frame weighing less than 900g, it’s surprising that the total weight of the bike adds up to 7.15kg. Given the high-end spec, it’s the hydraulics and discs that are the prime suspects for taking this figure higher than it might be. It’s a small penalty, but when paying this sort of money we’d really expect the best stats in every area. These niggles aside, the disc brakes irrefutably come out on top when compared with a conventional set-up.

Then there’s the groupset, Dura-Ace Di2, which, in conjunction with the hydraulic brakes, bestows a real ease when it comes to the bike’s controls. Of course, there is a sense of detachment too, as the bike almost manages itself. I personally like the feeling of a cable engaging a set of brake pads, and the tactility of shifting gears mechanically.

Yet I was constantly excited about riding the Defy. At any spare moment I was keen to hop aboard for an hour’s blast or a 100-mile day out. Some credit also has to go to the Zipp wheelset, which avoids the trend of disc brake-equipped wheels to bulk up at the rim to handle the extra forces, and felt as light and lively as any wheel I’ve ridden. But I’m not sold on discs yet, as there’s one final issue – compatibility.

The cycling world has not yet decided which disc-brake hub system will become standard. Giant has settled for the easiest standard, but the least likely to catch on. With traditional 9mm quick release rather than thru-axle wheels, it’s possible that upgrades could become difficult with this frame if wheel producers side with thru-axles. But with a spec like this, and no risk of brake-track rim wear, who needs upgrades?

For some the idea of spending eight grand on a Giant Defy will be challenging – especially with disc brakes. But I believe that this is just about the most technically advanced and high-performing road bike I’ve come across. If this is the future, there’s cause for excitement, as it brings together the thrill and speed of a road racer with the comfort and durability of an endurance build. It pains me to admit it, but while the Giant isn’t the bike of my dreams, it’s very nearly a perfect package.

Geometry

Spec