It's not surprising that Giant claims the current Propel aero road bikes are the fastest ever – that's usually the way – but we were seriously impressed when we reviewed the Advanced Pro 1 model back in the summer. It’s efficient, comfortable, and good value too, so it's certainly worth taking a good look.
When Giant announced its updated Propel bikes for the 2023 model year, it made some big claims, which is pretty normal for a major launch. It said that compared with the previous iteration, the top-level Propel Advanced SL improved aerodynamic drag by 6.21 watts at 40km/h (25mph) – in other words, you’d be able to achieve the same speed for less effort – and that the stiffness-to-weight ratio had improved by 26.4%.
You’ve probably got used to taking those kinds of claims with a pinch of salt – we certainly have – but the Propel Advanced Pro 1 put in a superb performance when we reviewed it.
The latest Propels mark a radical departure from previous models, to the extent that when they were first spotted ahead of launch, many people didn’t believe that they actually were Propels. Apart from retaining a horizontal top tube, just about everything else was altered.
The frame features truncated ellipse airfoil shapes in key areas, including the down tube, seat tube and seatstays.
“The frontal sections, where aerodynamics matter most, feature sculpted lines and that truncated ellipse shape to minimise drag,” says Giant. “We even created two different water bottle cages (one for the down tube, one for the seat tube) to minimise aerodynamic drag for each of these specific tubes.”
Those tubes are different profiles, so Giant’s bottle cages are shaped to blend with each.
Giant altered the shapes and diameters in sections of the head tube, down tube, and bottom bracket area to achieve greater stiffness.
On the flip side, the seat tube, chainstays and integrated seatpost were all re-engineered to provide a smoother ride. They’re far slimmer than on the previous generation Propel. As well as improving compliance, the skinnier back is also designed to save weight.
Comfort is one of the first things you notice when you ride the Giant Propel Advanced Pro 1. It’s impressive. Things have moved on a long way from the sometimes incredibly harsh aero bikes of old. The Propel feels pretty smooth with its 25mm tyres (that we measured closer to 28mm), and there’s space for tyres up to 30mm now if you want to go wider and drop the pressure.
The outstanding feature of the Propel, though, is its efficiency. There's little discernible movement at the bottom bracket when you're cranking out full power, and the front end feels equally tight, even when you're sprinting out of the saddle or pushing it hard into a sharp corner.
While we can't confirm Giant’s aero claims without a wind tunnel test, the Propel's nimble handling makes it easy to navigate through a group of riders or handle road defects confidently. It's responsive in turns and performs well in climbing despite not being the lightest option in its price range. Our size ML hit the road.cc scales at 8.47kg, better. If you want lighter, we weighed a Propel Advanced SL 0 (below, ML size, Shimano Dura-Ace Di2 build) at 6.96kg – although that model will set you back 12 grand.
Although it has changed from a Gloss Phoenix Fire/Helios Orange finish to Matte Carbon/Gloss Black, the price of the Giant Advanced Pro 1 remains the same for 2024 at £5,499. The least costly Propel is the £2,999 Propel Advanced 2. This model doesn’t have exactly the same frame as the more expensive Advanced Pro and Advanced SL bikes but it’s still very good quality and comes equipped with Shimano’s mid-level 105 mechanical groupset for £2,999.
Mat has been in cycling media since 1996, on titles including BikeRadar, Total Bike, Total Mountain Bike, What Mountain Bike and Mountain Biking UK, and he has been editor of 220 Triathlon and Cycling Plus. Mat has been road.cc technical editor for over a decade, 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 winner of the Cycling Media Award for Specialist Online Writer. Now over 50, he's riding road and gravel bikes most days for fun and fitness rather than training for competitions.