Giant Propel Advanced SL 0 review

The new Giant Propel has undergone some hefty changes in its latest revision. The resultant design is one of the most complete race bikes on the market and it’s already proven on the WorldTour: it won two stages of 2022’s Tour de France.

Reduced tube dimensions at the rear of the bike, top-quality build components from Cadex and refined integration mean the bike is lighter, more comfortable and easier to work on than the previous Propel, despite feeling just as fast as some of the best aero bikes on the market.

The Propel in its Advanced SL 0 guise costs a princely €12,000 / $12,500 / AU$13,999 (UK pricing is still TBC) but in both performance and practical terms the bike compares favourably with many similarly priced competitors.

Customers in the market for a money-no-object race bike will have a hard job looking past the Propel Advanced SL 0. It’s reasonable to suggest that Giant’s comprehensive range of tiers below the Advanced SL 0 should provide similarly decent options at more accessible price points too.

Giant Propel Advanced SL 0 development

The advantage of aerodynamic efficiency is undeniable but all too often that extra speed comes at the cost of other attributes that might otherwise be equally important and desirable.

In a road bike that generally means higher weight, reduced comfort, and though their bulky forms might not make it obvious, aero profiles can be worse in the stiffness stakes. The need for integrated everything makes setup and adjustment a practical pain too.

The Giant Propel has long been a fast bike but this latest iteration attempts to make it fast without those drawbacks. If Giant’s claims are to be believed the brand has been successful.

Despite it being in the region of 6 watts faster at 40kmh as a complete bike, the new Propel frameset is said to be 9.2% stiffer, 85% more compliant at the saddle and 225g lighter to boot, while the cockpit design is far simpler and better looking than the brutalist arrangement of spacers and caps on the last bike.

While I couldn’t directly confirm that frameset weight loss figure, weighing the bike at 6.9kg (size ML, with cages and computer mount) certainly did nothing to make me doubt it.

More tangibly, my ride experience aboard the bike aligned with Giant’s other performance claims too. It’s the first aero bike I’ve ridden with none of the usually associated disadvantages, and my time on it was an unmitigated joy from start to finish.

Giant Propel Advanced SL 0 frameset

Of all the Propel’s improvement claims, the changes in weight and comfort are the most dramatic and a good chunk of both is derived from drastically slimming down the rear half of the bike.

The solution is simple in premise really, even if Giant says the execution was trickier to perfect: the tubes making up the seat tube junction are still a version of Giant’s ‘truncated ellipse’ aero profile, but are just smaller. Smaller tubes inherently flex more and weigh less than more elongated ones.

Giant says decision to continue with an integrated seatpost, as it does on its top-tier TCR race bike as well, was to ensure that the area could be as well-tuned and as light as possible.

While it may be perceived as a limiting factor, Giant offers a topper that provides up to 45mm of height adjustment, which should be more than enough range to cover any saddle height changes.

Blending additional stiffness into the mix as well required Giant to leverage its considerable expertise in composite fabrication, using techniques like laser cutting for more precise carbon swatch positioning, automating part of the layup process for more consistent results.

More superficially, Giant has adjusted the profiles of the Propel’s head tube, down tube and bottom bracket junction, and stuck with a D-shaped version of its proprietary OverDrive 2 oversize steerer on the Propel’s fork.

Giant Propel Advanced SL 0 build

The Propel’s shallower tubes, while they facilitate less weight and more compliance, are less able to manage airflow across the bike, so Giant looked to regain drag efficiency in other areas to achieve its ‘6 watts faster’ claim.

There are some neat small touches to that effect, such as the individually profiled bottle cages, but Giant does have to place emphasis on the use of sister-brand Cadex’s new Ultra 50 wheels and Aero tyres with the new Propel in order to obtain the maximum level of aerodynamic efficiency.

It’s unclear how much of the aero gain they imbue the Propel with, but given the wheels’ and tyres’ excellent features I don’t see much of a reason to need to use anything else from a performance perspective.

The Aero tyres seem robust yet grippy and the wheels have one of the most technologically progressive designs on the market, using bladed carbon spokes, ceramic bearings and a hookless rim profile.

They feel like they carry high speed well and feel stiff despite their uncommonly light 1,349g claimed weight. The only niggle I have with them is their embarrassingly loud freehub, which drew a lot of unwanted attention on rides. While it isn’t officially recommended, I’d add some extra grease to the freehub mechanism to quieten that down if I owned a set.

In any case, given that Giant are only selling the Propel Advanced SL as a complete bike for the time being, quite to what extent the components are responsible for the bike’s overall aerodynamic qualities is mostly irrelevant.

The bar and stem are the other components that are said to contribute to the Propel’s speed, but arguably the bigger talking point with those is their much more refined integration.

Rather than the convoluted system of caps and spacers on the previous bike, smoothly profiled headset spacers now guide cables into the frame after they run along a recess on the underside of the stem.

While the OverDrive 2 steerer dimension necessitates a specific pairing with Giant’s new Contact SLR Aero stem, any bars can be used because the stem uses a regular clamping interface and its channelling is open enough to accept cable routing from a variety of angles.

The stem is light, simple in design, feels stiff and is available in a range of lengths though, so I can’t see that there should be a need to use anything else.

In a performance sense the bars and stem are adequate enough to make any modifications unnecessary, and practically I found the front end of the Propel to be equally good.

Changes to bar height and orientation, front end disassembly and cable routing are as simple to complete as other less integrated bikes. To have that adjustability alongside the Propel’s performance attributes is rare and valuable.

Considering that this is the top-tier Propel, it would have been nice to have Cadex’s Boost saddle rather than Giant’s Fleet SLR, which technically sits below the Boost, but everywhere else the spec is flawless.

Shimano’s Dura-Ace Di2 R9200 groupset even comes with the power meter-equipped version of the crankset. On bikes at this cost that type of upgrade is still a disappointingly rare, so it is great to see Giant add value here.

Giant Propel Advanced SL 0 geometry and sizing

In comparison to the scale of change in the performance aspects of the Propel, the geometry changes Giant has made are minor. The brand has been content to stick pretty faithfully to its tried and true race bike geometry.

Most figures remain typically aggressive, but on the new bike Giant has chilled the handling out a touch, having created slightly longer trail figures for a given tyre size.

The brand has lowered the bottom bracket too in an attempt to improve stability.

Six sizes cater for the vast majority of riders, with Giant altering regular dimensions like head angle and length to homogenise ride characterises across sizes. Every size uses the same chainstay length and fork rake.

Riding the Giant Propel Advanced SL 0

The geometry changes chime nicely with the Propel’s wider developments and contribute to the bike’s overall well-roundedness.

I can think of just one or two competitors that may come close on paper to matching how well the Propel satisfies opposing ride attributes, such as Factor’s Ostro VAM, but I’ve not had first-hand experience of any design that performs better as a race bike. The Giant Propel feels exceptionally quick over all terrain.

The Propel’s aero tube profiles married to its light overall weight means the bike not only accelerates from low speed like dedicated climber’s bike but feels like it holds high speed in a way the best aero bikes do too, which generally are heavier and/or harsher than the Propel.

I think the stiff cockpit, oversize fork steerer and correspondingly chunky head tube and down tube help to imbue the bike with decent torsional rigidity, which contributes to the feeling of the bike’s willing acceleration.

On the other hand, the slim back end means the Propel’s ride quality doesn’t become uncomfortable. For more casual riders, 28mm tyres would only help in the comfort stakes but given this bike is aimed at racers – and the Cadex 50 Ultra wheels are designed to work with specific Cadex Aero tyres – the 25mm specced width doesn’t feel off-key with the bike in a general sense.

Giant Propel Advanced SL 0 verdict

Achieving such well-rounded performance is an excellent feat, but has led Giant to stray off the beaten path in terms of total generic compatibility. The seatpost is integrated and the stem is proprietary.

Such limitations may be a turn off for potential customers, but I believe Giant has managed to mitigate much of the disadvantage.

The stem is functionally excellent and is offered in plenty of options, while the seat mast topper offers 45mm of height adjustment, which should quell any concerns around adjustment to accommodate saddle changes or future owners.

With those issues largely addressed, I’m left shrugging my shoulders for an area in which to mark the bike down. While the TCR will always be lighter still and offer bigger tyre clearance, if I were a consumer in the market for a premium race bike, I’d have a hard time looking past the Giant Propel Advanced SL 0.

• Buy the Giant Propel Advanced SL 0 soon from giantbicycles.com (€12,000/$12,500/AU$13,999/£TBC)

Giant Propel Advanced SL 0 spec

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Images: Lizzie Crabb

Pick of the kit

Kask Protone Icon helmet

The long-standing success the original Protone enjoyed on the WorldTour and its popularity at an amateur level were testament to its excellent design, so unsurprisingly Kask hasn’t changed all that much in the updated Protone Icon.

I like the way Kask has modernised the helmet’s looks, and its fit, comfort and ventilation are even better than before.

While some would no doubt have liked to see the brand incorporate some sort of Mips-like mechanism, Kask does say the helmet conforms to its own rotational impact standards.

Giant Propel Advanced SL 0 alternatives

Giant TCR Advanced SL 0

If extreme light weight is your thing, the £9,999 Giant TCR Advanced SL 0 is made of the same composite blend as the Propel, but less aggressive tube shaping makes the frameset more than 150g lighter.

• Buy the Giant TCR Advanced SL 0 from giant-bicycles.com (£10,999)

Giant Propel Advanced 

The €4,700 (approx £4,100) Propel Advanced 1 build is largely the same as the Advanced SL 0 in its form, but it uses less premium materials in its frame and finishing kit and a lower-tier groupset.

• Buy the Giant Propel Advanced 1 soon from giantbicycles.com (€4,700/£TBC)

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