In its attempt to build the ultimate high-performance (UCI legal) road bike, Giant took just about every top-end feature and popular technology and crammed it into one bike: the Propel Advanced SL 0 Disc.

As you might expect with the launch of a brand-new model, Giant’s representatives claim the Propel’s aerodynamics, overall stiffness, and stiffness-to-weight ratio are on par with or exceed the bike’s main competitors, be they rim-brake or disc-brake equipped. It’s certainly possible that those claims are accurate. But those characteristics did not jump to mind while I was riding it. What struck me about the Propel was its balance.

It is remarkably unburdened for a bike crammed with so much – an aerodynamic frame, disc brakes, a power meter (the new Dura-Ace power crank), electronic shifting, deep-section tubeless wheels, and integration, including the seat mast and post, as well as the bar and stem. It’s light (our sample weighed 7.3kg) yet stable in crosswinds, and it’s even quiet.

It feels like a race bike in all the ways it should: It’s reactive, it’s stiff, it’s slippery. It’s brilliant on the flats, but it’s also great for climbing, and even better for descending. The handling is excellent; it’s smooth and damped enough to ride for hours. And the braking and drivetrain are nearly perfect. That performance is enhanced by Shimano’s peerless Dura-Ace Di2 group. With the included power meter (not on our sample) and sprint shifters, it’s just a set of tubulars away from a World Tour race bike.

While this bike certainly has its compromises – the single-piece bar and stem, for example, which prevents riders from choosing a bar width independent of stem length – it manages to avoid almost all the turnoffs (additional weight, decreased frame stiffness, harsher ride, more drag) that detract from aero bikes with disc brakes. And in doing so, Giant has built the class-leading aero road bike – and one of the best high-performance bikes, period.

WEIGHT: 7.3kg (M)

This Bike Has It All:
Tubeless-ready, carbon clincher wheels (depth: 42mm front, 65mm rear)
Tubeless-ready tires (25mm) F Integrated seat mast
Carbon-railed saddle with relief channel
Shimano Dura-Ace Di2 electronic shifting
BB86 press-fit bottom bracket
Shimano Dura-Ace power meter crank
Shimano Dura-Ace hydraulic disc brakes
Truncated airfoil tube shapes
Carbon composite frame and fork (composites woven in Giant’s factory)
Hidden brake and derailleur lines
Oversize 1.25-inch upper-steerer diameter
Shimano EW-WU111 wireless unit (connects Di2 to ANT+/Bluetooth devices)
Remote sprint shifters
Aerodynamically tuned carbon bar and stem
Thru-axles front (100x12mm) and rear (142x12mm)
Garmin out-in-front computer mount

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