Giant Propel Advanced 1

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.

Is it really aero?

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.

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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.

How does it ride?

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.

Is it comfortable?

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.

What's the geometry like?

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.

> Read Your Complete Guide to Giant's 2016 Road Bikes here

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.

What about the components?

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...

> Check out our complete Ultegra groupset review here

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.

Summing up

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.

Verdict

Fast and agile aero road bike that offers exceptional value for money