Giant Propel Advanced Pro 1 2023

The Giant Propel Advanced Pro 1 is an excellent aero road bike that provides loads of stiffness and efficiency and, what's more surprising, a good level of comfort and straightforward front-end adjustment. It might take a while to get your head around spending £5,500 on a bike with a third-tier SRAM Rival eTap AXS groupset but it's good value against models from other big brands.

If you're interested in the Propel Advanced Pro 1, check out our guide to the best road bikes for more options, from £300 to £13,000.

Ride

The Giant Propel Advanced Pro 1 is all about efficiency and that's apparent from the get-go. This is a bike you can muscle about without worrying that it's going to flex from your best efforts. 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 fast right-angled bend.

The new Propel, which was revealed to the world last summer, uses truncated ellipse frame tubes that are considerably shallower than before, but Giant reckons that the bike as a whole is faster. It says that the top-level Propel Advanced SL allows you to achieve 40km/h while putting out 6.21 watts less power than on the previous model. This equates to 'a 2.6% aerodynamic improvement'. This claim relates to the bike as a whole, new handlebar, stem, wheels and tyres included.

The Propel Advanced Pro 1 that we have here has a frame that's the same shape although you get a standard rather than an integrated seatpost. We can't independently verify Giant's aero claims, we're just reporting them.

Back in ye olde days, aero road bikes were a bit like time trial bikes in that they were great for straight-line speed and long, sweeping bends but a bit of a dog elsewhere. Okay, that's a bit of an exaggeration, but on the whole, handling wasn't great and comfort was... well, it was a compromise.

That's totally not the case here. For a start, the Propel's handling is nimble. Steering is quick, so navigating through a group of other riders or around defects in the road surface is a cinch. This coaxes you to attack fast and tight turns at speed, confident that the bike's reactions will see you right even if your judgement is a bit off.

I didn't find it too much to handle in crosswinds either, although I don't tend to get shifted about as much as smaller riders anyway. On one stupidly windy day I felt like I had to keep my wits about me to avoid getting buffeted around, but even with 50mm-deep wheels – Giant SLR 1 50 Carbon Discs – it wasn't an issue the rest of the time.

As for comfort, the Propel offers plenty. Head out on a big ride at the weekend and it doesn't just feel okay for an aero bike, it feels, you know, good. There's not too much vibration coming up through either Giant's Fleet SL saddle or the Contact SL Aero handlebar.

Let's not go over the top; it's not endurance bike smooth, but it's certainly no filling rattler, and tubeless tyres – badged 25mm but measuring over 28mm on the SLR 1 50 Carbon Disc wheels – allow you to tune the feel. If you want to run them at really low pressures, fill yer boots.

Maybe the slim stays and seat tube play a part, maybe the fact that I have loads of seatpost extending out of the frame helps, but I never felt even remotely shaken up by this bike over two months of riding.

The Propel Advanced Pro 1 is an able climber too. Our size ML hit the road.cc scales at 8.47kg meaning it's far from the lightest £5,500 bike you can buy, but lighter doesn't always mean better. Granted, you probably won't be buying the Propel for its climbing prowess alone but it gets on with the job just fine. No complaints at all.

The Propel Advanced SL0 that came visiting road.cc last year (we couldn't ride it) showed 6.96kg (ML size, Shimano Dura-Ace Di2 build) on our scales, so if you really want a lighter weight that option is out there. The Advanced SL has a frame made from a higher-grade composite than the Advanced Pro and benefits from expensive manufacturing techniques – such as the laser cutting of swatches of composite that then go through an automated assembly process to place them precisely in key areas of the frame and fork to keep weight down. It's available in various high-end builds. So many positives!

Small point, though: the Propel Advanced SL 0 costs £11,999. You could buy two Propel Advanced Pro 1s for that and still have change for sweets or something. A helluva lot of sweets.

Geometry

We had the ML-sized Giant Propel Advanced Pro 1 in for review (according to Giant's guide, I should take a size L, but I wanted a top tube as close to 570mm as possible). This one comes with a not-far-off horizontal 565mm top tube, a 545mm seat tube and a 165mm head tube. The head angle and seat angle on this size are both 73 degrees.

You get a stack height of 562mm and a reach of 393mm, giving a stack/reach of 1.43. The riding position is aggressive, as you'd expect on an aero bike, but not crazily so. I played it safe with 20mm of spacers underneath the stem – it's always better to err on the side of caution rather than cutting a steerer too short and regretting it – but you could lower the front end easily enough.

The spacers come in two interlocking parts so it's easy to remove them – or add them back in – without the need to re-plumb the brake hoses. The lower (or lowest) 10mm spacer, which junctions as a hose guide, doesn't split and Giant recommends that you keep it.

The Propel's geometry is almost the same as that of Giant's TCR road bike that focuses on light weight and stiffness. Granted, the TCR has a shorter seat tube but that's because the top tube slopes downwards and foreshortens it. The stack, reach and frame angles are exactly the same, as are chainstay length (405mm) and wheelbase (991mm). If you happen to have ridden a TCR and the fit is right, you know what you're getting here.

Adjustable front end

The front end of the Propel is interesting – no, really – so I'll tell you a little about it. Older readers might remember – we're talking pre-August 2022 here – that the previous generation Propel had an integrated cable system that worked fine but it was a bit convoluted. Brake hoses and any wires/cables were routed above the stem and into the frame behind the steerer tube. A cover hid them out of sight and away from the wind.

Giant has binned that idea and introduced a new two-piece Contact SLR Aero handlebar and stem setup. Our review bike is equipped with a SRAM Rival eTap AXS groupset so there are no wires to worry about, but the brake hoses run inside the handlebar and pop out in the centre. You can't see them, though – not unless you go hunting – because they're then routed on the underside of the stem.

Think of the stem profile as similar to that of a letter n. Structurally, that must be a challenge but the fact that there's no bottom section means it's easy to run the hoses in the gap. They then go down into the head tube, the necessary space provided by a D-section fork steerer (we really are getting through the letters today, aren't we? It's like Sesame Street around here).

As already mentioned, two-part interlocking spacers allow you to adjust the front-end height easily. Obviously, you'll need to redo the brake hoses if you want to swap the handlebar, but you can change to a different length stem without any complications. Giant offers the Contact SL Aero Stem in 80mm to 140mm versions, although only in the same -10° drop.

The D-shaped fork steerer means you're wedded to Giant for all your future stem needs. Giant does offer 32 versions of stems that'll fit, the Contact SL in aluminium and Contact SLR in composite.

A side benefit of the D-shaped steerer is that you can never put the stem on skew-whiff; it only fits in one direction. If you ever wanted to move away from Giant's Contact SL Aero handlebar, that's perfectly possible, the stem taking a standard 31.8mm bar.

Components

The Propel Advanced Pro 1 comes with Giant's Vector composite seatpost that offers a -5°/+15° offset so there's loads of adjustment there. Giant's Fleet SL shorty saddle is really good too. Forgiving but not squishy, it has enough foam to take the edge off rough roads along with Giant's Particle Flow tech which allows 'free-flowing particles' to move around in there to reduce pressure. The bottom line – ahem! – is that it's really comfy.

The Propel Advanced Pro is available in three flavours, all 12-speed and with hydraulic disc brakes. The Propel Advanced Pro 0 AXS (£6,399) gets SRAM's Force eTap AXS groupset, the Propel Advanced Pro 0 Di2 (£5,999) is a Shimano Ultegra Di2 build, and the Propel Advanced Pro 1 that I've been riding is equipped with SRAM Rival eTap.

SRAM Rival eTap AXS isn't especially light but it's solid, reliable stuff. The chainset is a 48/35-tooth matched up to a 10-30 cassette so you get some pretty big gears, although you might prefer a couple of smaller ones for the steep hills at the end of a long day in the saddle.

Rather than going for a SRAM/Quarq power meter, Giant specs its own spider-based Power Halo which offers left/right balance and a claimed accuracy of +/-1.5%. I won't go into a full critique of the power meter here – that would be a whole review in itself.

Giant's SLR 1 50 Carbon Disc wheels are very good, feeling lively for something of their 50mm depth without being especially affected by crosswinds. The hookless carbon rims have a 22.4mm inner width and a 30mm outer width and Giant says they'll accommodate tyres up to 32mm wide, although that's academic here because the frame/fork won't take anything wider than a measured 30mm.

For me, that's not a huge restriction. The Giant Gavia Course 1 tyres fitted are actually 700C x 25mm but you'd never know that by looking at them, or even by measuring them. The road.cc vernier callipers say they're over 28mm wide when inflated to 6 bar (Giant gives them a range of 5.8-8.6 bar) on these rims.

Some recently launched aero road bikes can take wider tyres – the latest Cervelo S5 can take tyres up to 34mm, for example – but I'm not sure that too many people want anything wider than 30mm on an aero road bike right now, although who knows where we'll be two or three years down the line.

Speaking of tyres, Giant Gavia Course 1s offer excellent grip and decent puncture resistance although they're a little heavy and aren't the most supple. Although Giant describes them as 'Premium Road Race tyres', that's a push. They don't have the same speed-focused abilities as the rest of the bike, although they're fine to be going on with.

Like other Propels, this one comes with one bottle cage designed especially for the down tube and another that's seat tube specific. Although they look similar, the width of the base of each cage matches the relevant tube.

One other little feature that's worth a quick mention is the out-front computer mount that's fixed in place by the bolts for the stem's front plate. It's a neat design, and swappable inserts allow it to accept Garmin, Wahoo, and Giant's own computers.

The money bit

If you're struggling to rationalise a bike with a third-tier groupset costing £5,499, join the club. The trouble is, that's the reality of how the bike market has changed recently.

Specialized's Tarmac SL Comp with SRAM Rival eTap AXS is £5,500, and Trek's Madone SLR 6 AXS Gen 7 with SRAM Rival is – wait for it – £8,250. Cannondale's SystemSix isn't available with SRAM Rival, although the Shimano Ultegra 11-speed model (with mechanical shifting) is £5,250. It's only direct-to-consumer Canyon that offers an aero road bike equipped with a SRAM Rival eTap AXS groupset for a significantly lower price, the Aeroad CF SLX 7 Disc eTap coming in at £4,799. Sorry to be the bearer of bad news but prices aren't what they were even a couple of years ago.

Conclusion

Overall, the Giant Propel Advanced Pro 1 is an excellent proposition. It's fast and efficient with quick handling and a surprisingly high level of comfort, especially for an aero road bike. Compared with models from other big brands, it's also decent value for money.

Verdict

Excellent aero road bike that provides efficiency, comfort, and good value in the current market