The all new 2105 Giant Defy Advance 1 provides tested best-of-class in weight and stiffness
—Defy Advanced 1: Carbon-fiber frame, mechanical disc brakes, D-Fuse seatpost, Shimano Ultegra 6800 mechanical, TRP Spyre mechanical disc brakes, Giant S-R2 rims
The stats don't begin to tell the story of the huge revision Giant has put into the new Defy line. Over the years, Defy has been about basic built for comfort and practical road use. With the changes in 2015, the Defy may be more comfortable and practical than ever, but there is nothing basic about it.
The engineers opted to go 100% disc on the advanced carbon-fiber frame end of the line. The chose to stay with quick release rather than move to through axles, feeling that grabbing mountain bike axles wasn't the answer, and preferring to wait until there was more clarity on the road bike standards.
Bicycling.com says:
Giant calls the Defy an endurance road bike—I’m not so sure that such classification is necessary. Much like modern trail bikes are to the world of knobby tires, the Defy seems to me to be a bike you’d choose to ride on almost any ride, any day, on any terrain, and feel confident and comfortable the whole time.Specifically, they point out that:
The trick on this bike was to come up with lightness, stiffness, and still get performance and comfort that this bike is noted for.The New Defy Design
The tube shapes are different, subtly in some places and more dramatically in others. The old aero-shape seatmast (or seatpost, depending on the model is gone in favor of a
flat-backed profile Giant calls D-Fuse, which first saw use on the TCX cyclocross model. The seatstays narrow to gossamer thinness, and attach lower down the seat tube to help prevent vibration from traveling up to the saddle.
RoadBikeReview.com interviewed Jon Swansan, global road category manager:
Weight was also a huge design driver. Swanson says the top end frame is the lightest road frame Giant has ever produced. “The perception is that with road disc you have to pay a weight penalty,” said Swanson. “We approached it as how do we offset that weight. And we actually dropped 50 grams on our top end frames, which is pretty significant when you see our competition having to add 40-50 grams to get disc tabs on.”Giant took this bike to the lab against it's most relevant competitors. They looked at weight, stiffness, and compliance, where compliance is the comfort to feet, hands, and rear end. The lower the amount of vibration that comes from the road, through the bike, to the three points of contact on the bike, the better for comfort in a longer ride.
That weight was shed in part by using hollowed carbon dropouts, eliminating the brake bridge, and generally minimizing the need for reinforcement frame material by reducing the number of holes in the carbon frame. The front brake hose is routed externally; all other cables/hoses go into one side of the frame because when you punch a hole in frame you have to add weight with reinforcing material. Instead Giant made a single slightly larger hole on the non-driveside.
As you can see, the Defy handily beat the others in both weight and stiffness.
When it came to compliance, the best number was chalked up by Cannondale's Synapse. However, if you look at the stiffness data above on that same model, you'll see that the bike performed very poorly in that category, apparently preferring to compromise on the side of comfort.
