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The Giant Propel Advanced 1 is a fast and reactive aero road bike that offers excellent value. There are slightly better climbers out there, but if you're after straight-line speed and snappy handling, this bike has loads to offer.
The Propel Advanced 1 is a very fast bike (for people who object to a bike being described as 'fast', that means that for a given power input it is quick compared to competitors). Tuck yourself down on the drops, hit the pedals hard and you're rewarded with impressive speed for your efforts. This thing can really shift.
Although the materials are different, the Propel Advanced 1 is a very similar design to Giant's top level Propel Advanced SL – the only distinction is that the SL version has an integrated seatpost. The tube profiles are identical so you benefit from the same aero technology as Team Giant-Alpecin but at a more affordable price.
We don't have the facilities to verify Giant's claims on aerodynamic efficiency so we'll just report them and you can choose whether or not you're convinced. Giant says that the AeroSystem Shaping Technology of its Propel Advanced SL (the same tube shaping as our Propel Advanced 1, remember, and the same brake positioning) "saves 12-36 seconds over a distance of 40km at a speed of 40km/h compared to key aero bike competitors".
Okay, that doesn't quite make sense. If two bikes are both going 40km/h they're going to cover 40km in exactly the same time – an hour. But you know what Giant means, right? If you put in the same amount of power, you'd cover the 40km slightly quicker on the Propel.
Who are these competitors of which Giant speaks? You can find out on this video from when the latest version of the Propel was released.
Personally, I'd take a lot of the details of aero claims from all manufacturers with a pinch of salt. Whether bike X is quicker than bike Y over a given distance depends on a million and one different factors. But Giant has designed this bike with the aim of minimising drag from all angles, and my speed versus power figures over regular routes convince me that the designers have done a very good job.
The Propel Advanced 1 isn't simply a one-trick pony. Aside from its aero credentials, it's a bike with plenty of frame stiffness.
Giant uses what it calls its 'PowerCore' design, meaning that the bottom bracket/chainstay area is oversized. Although it uses a 24mm rather than a 30mm axle, the bearings are incorporated within the BB shell.
The result is a bottom bracket that barely moves off-centre even when you're duking it out in a Marcel Kittel streak for the line.
The front end offers plenty of rigidity too, thanks to Giant's OverDrive arrangement. That's Giant's way of saying that the head tube is built around a standard 1 1/8in bearing up top and a 1 1/4in bearing down below. Although the fork legs are composite, the steerer that slots in there is aluminium (higher level Propels have full composite forks).
I've ridden bikes that offer a higher level of accuracy when gunning it through tight corners, but the Propel Advanced 1 provides you with enough confidence to lean the bike over hard and lay off the brakes, and to jump about in the group to get on the right wheel.
As an aero bike, the Propel Advanced 1 isn't as featherweight as some competitors – the extra material used to make the tubes deep and slippery obviously adds a bit – but at 8.05kg (17.7lb) it's still reasonably light for something of this price. It struggles just a fraction to keep up with lighter bikes coming out of the tight corners and on the steepest of climbs, but that's being really picky. It's certainly no slouch in either of those situations.
In terms of comfort, the Propel Advanced 1 feels like a race bike – which is exactly what it is. That's not a euphemism for saying it's harsh – that's not the case at all – but it does sit towards the firm end of the spectrum.
If the roads around your way ride are less than perfect – and, let's face it, they are less than perfect – the Propel Advanced 1 will pass on the message.
That's partly down to Giant's own P-SL1 tyres, though. There's absolutely nothing wrong with them – they're grippy and reasonably light – but they are 23mm wide when most of us have got used to the extra cushioning provided by 25s these days.
If the amount of buzz bothers you, there's enough room in there to switch to 25s. I did exactly that for a while and it certainly made a significant difference to the feel of the ride.
We had the XL sized Propel Advanced 1 in for review, but I'll tell you about the geometry of the M/L model because that's relevant to more people (sorry big fellas, you've been outvoted).
Giant calls the M/L a 545mm frame. It has a 570mm top tube and a 170mm head tube. The head angle is 73 degrees and the seat angle is 72.5 degrees.
The stack (vertical distance from the centre of the bottom bracket to the top of the head tube) is 566mm and the reach (the horizontal distance between those points) is 391mm.
It's an aggressive (but not crazy) geometry that's exactly the same as Giant uses for its higher level Propels and very similar to that of the TCR lightweight race bikes.
I removed all the headset spacers on our review bike (well, I stuck them on top of the stem because cutting down the steerer tube on a borrowed bike just isn't the done thing) and got myself into a position that felt both comfortable and efficient. You're likely to be able to do the same.
The Propel Advanced 1 comes with a mostly Shimano Ultegra mechanical groupset. The only significant deviation from the theme is the brakeset, and there's a good reason for that. Giant specs its own SpeedControl linear pull (V-type) brakes because the arms sit in line with the fork legs and seatstays to minimise drag.
The derailleurs, shifters, cassette and chainset are all Ultegra, and we've nothing but positive things to say about Shimano's second-tier road groupset. The shifting is light-action and good under load, the levers are comfortable and easy to use, it's all lightweight...
I'm a big fan of the chainset in this 52/36-tooth flavour. You need that 52t chainring on a race bike, and the 36t ring makes life a whole lot easier than a 39 on the steep stuff. It's a good choice.
Pretty much all the other components are Giant's own. They might not have the glamour of kit from some other brands but it's hard to fault the performance. The Contact aluminium bar and stem don't flex much, the Performance Road saddle is comfortable if a little bulky, and the P-A2 Aero rims spin smoothly on sealed bearing hubs. They're a little flexy and are probably worth an upgrade to something deeper further down the line, but they've served me well through a lengthy test period.
The Giant Propel Advanced 1 is a quick bike with a high level of frame rigidity. It reacts well to being chucked in and out of corners and handles sharply in the hurly-burly of a fast-riding group. It's not quite as adept at accelerating and climbing as superlight rivals, but this is still a very skilled race bike. With an almost complete Shimano Ultegra groupset, it's also excellent value.
Fast and agile aero road bike that offers exceptional value for money
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road.cc test report
Make and model: Giant Propel Advanced 1
Size tested: XL
About the bike
State the frame and fork material and method of construction. List the components used to build up the bike.
Frame Advanced-Grade Composite
Fork Advanced-Grade Composite, Hybrid OverDrive Steerer
Handlebar Giant Contact
Stem Giant Connect
Seatpost Giant Vector Composite
Saddle Giant Performance Road
Shifters Shimano Ultegra
Front Derailleur Shimano Ultegra
Rear Derailleur Shimano Ultegra
Brakes Giant SpeedControl
Brake Levers Shimano Ultegra
Cassette Shimano Ultegra 11-28
Chain KMC X11L
Crankset Shimano Ultegra 36/52
Bottom Bracket Shimano PressFit
Rims Giant P-A2 Aero
Hubs Giant Performance Tracker Road, Sealed Bearing
Spokes Sapim Race
Tyres Giant P-SL1, Front and Rear Specific, 700x23mm, Folding
Tell us what the bike is for, and who it's aimed at. What do the manufacturers say about it? How does that compare to your own feelings about the bike?
It's designed as a race bike although it's suitable for any type of performance-type sporty riding.
Giant says: "Best-in-class aerodynamics plus sharp yet stable handling on the road, you get it all with Propel Advanced. Engineered with AeroSystem Shaping Technology and Advanced grade composite, this race ready rocket ship delivers lightweight performance and a stiff chassis for sprinting.
"The Vector seatpost offers wide ranging adjustability with minimal drag. An OverDrive steerer tube and PowerCore bottom bracket help improve its sharp handling and pedalling efficiency''the perfect combo when you're at the front of the pack."
Frame and fork
Tell us about the materials used in the frame and fork?
The frame and fork legs are made from Giant's Advanced Grade Composite.
"High-performance T-700 raw carbon fibre is used to produce custom composite material in Giant's own composite factory," says Giant. "Extremely lightweight, stiff and compliant, these handcrafted frames feature the following materials and processes:
MATERIALS: High Performance-grade raw carbon material features an excellent stiffness-to-weight ratio.
RESIN: High Performance formula provides excellent void minimisation (bubbles) while maintaining outstanding strength. And vibration absorbing particles are added to help disperse road shock.
MODIFIED MONOCOQUE CONSTRUCTION: The front triangle (down tube, head tube, top tube, seat tube) is assembled and moulded as one continuous piece. This front half is then joined to the rear chainstays and seatstays in a secondary process. This process eliminates the outermost woven composite sheet to reduce weight without affecting ride quality, strength or stiffness."
Tell us about the geometry of the frame and fork?
You get a race geometry here: aggressive but not too extreme. I've covered this in more detail in the main text.
How was the bike in terms of height and reach? How did it compare to other bikes of the same stated size?
Most people will be able to get a position that's as low as they want for efficiency.
Riding the bike
Was the bike comfortable to ride? Tell us how you felt about the ride quality.
It's a fairly typical road bike feel, although the 23mm tyres do make things a little firmer than you get with 25s.
Did the bike feel stiff in the right places? Did any part of the bike feel too stiff or too flexible?
It certainly feels stiff through the bottom bracket and it's pretty sturdy up front too.
How did the bike transfer power? Did it feel efficient?
It does feel like your effort is getting transferred into forward motion rather than flexing the frame.
Was there any toe-clip overlap with the front wheel? If so, was it a problem?
How would you describe the steering? Was it lively, neutral or unresponsive? On the lively side of neutral so it's easy to change your line according to the situation.
Which components had the most effect (good or bad) on the bike's comfort? would you recommend any changes?
Ultegra levers are always very comfortable. The handlebar is a bit too skinny for my taste. If it was my bike, I'd fit something with a larger diameter to fill my palms more.
If you want more comfort, the obvious change would be to change the 23mm tyres for 25s.
Which components had the most effect (good or bad) on the bike's stiffness? would you recommend any changes?
The wheels flexed a little throughout testing. I'd upgrade them to something deeper for racing.
Ultegra is exceptionally good value on an aero bike of this price.
Wheels and tyres
Tell us some more about the wheels and tyres.Did they work well in the conditions you encountered? Would you change the wheels or tyres? If so, what for?
I found the wheels would flex a little more than is ideal. They're decent enough, they run very smoothly, and the freehub is silent (you might prefer a clicky one, but I like peace and quiet!). They would be my first upgrade, especially for racing.
Did you enjoy riding the bike? Yes
Would you consider buying the bike? If I was in the market for an aero road bike at this price, definitely.
Would you recommend the bike to a friend? Yes
Use this box to explain your score
This is a very good bike at an exceptionally good price. The fact that you get a full (well, very nearly full) Shimano Ultegra groupset swings it a 9 rather than an 8.
About the tester
I usually ride: My best bike is:
I've been riding for: Over 20 years I ride: Most days I would class myself as: Expert
I regularly do the following types of riding: commuting, club rides, sportives, general fitness riding
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 pushing 50, he's riding road and gravel bikes most days for fun and fitness rather than training for competitions.