The fourth-generation aero road bike arrives lighter, faster, and smoother, with an 18.4-watt total system advantage over its predecessor.
Giant has announced the fourth-generation of their aero road race bike, the Propel. Developed alongside Team Jayco AlUla and refined through extensive wind tunnel testing with an all-new 3D-printed dynamic mannequin, the new Propel is built around what Giant calls a “total speed system” that treats the rider, frame, cockpit, wheels, and tyres as a single aerodynamic unit. The new bike offers 18.4 watts less total system resistance, is 355g lighter in flagship trim, and has 25% more rear-end compliance.
The range spans three tiers: the pro-level Propel Advanced SL, the Propel Advanced Pro, and the accessible Propel Advanced. All share the same AeroSystem Shaping philosophy and integrated design approach, with the key differences coming down to carbon grade, componentry, and wheelset spec.
Top-End Speed
The headline performance claim is an 18.4-watt saving in total system resistance over the previous generation, measured at 40 km/h. That translates to 72 seconds saved over a 40 km effort at constant speed. The gains come from across the whole system: a reengineered AeroSystem frame, new integrated one-piece cockpit, 50mm hookless carbon wheels, and new CADEX Aero tyres that smooth airflow at the tyre-to-rim interface while reducing rolling resistance.
Giant’s OverDrive Aero technology pairs a slim, tapered head tube with a D-shaped fork steerer tube and spacers, routing all cables internally through the integrated handlebar/stem unit and frame. The Contact SLR Aero Integrated and Contact SL Aero Integrated handlebars feature flat backs, narrow tops, and reduced width at both the tops and drops to narrow the rider’s frontal area.
Instant Speed
The flagship Propel Advanced SL frame is 45g lighter than the outgoing model. Combined with the new one-piece cockpit, CADEX Max 50 WheelSystem (1,290g with tape and valves), CADEX Aero tyres, and weight savings across components down to the bottle cages, the total reduction for the Propel Advanced SL 0 comes to 355g.
Stiffness has gone up too. The Advanced SL frameset shows 3.4% greater torsional stiffness and a 2.4% boost in pedalling stiffness over the previous generation, adding up to a 5.7% improvement in stiffness-to-weight ratio. At a system level, Giant claims a 14.8% increase in system handling efficiency and a 14.2% boost in system pedalling efficiency.
Sustained Speed
One of the most significant developments on the new Propel is compliance. A reengineered seat tube, chainstays, and integrated seatpost (on the Advanced SL) deliver up to 25% greater vertical compliance at the rear. The fork and integrated cockpit add 12.8% more front-end compliance. The result is a noticeably smoother ride that helps maintain speed over rough roads with less rider fatigue.
Tyre clearance has been expanded to 32mm across the range, allowing riders to run higher-volume rubber at lower pressures for reduced rolling resistance and improved comfort. The CADEX Aero tyres reduce rolling resistance by 2.8 watts per wheel compared to the outgoing model, while the Gavia Course tyre saves 1.8 watts.
Key Highlights
18.4 watts less total system resistance. Measured at 40 km/h, the new Propel Advanced SL slashes total resistance from 267.76 watts to 249.32 watts compared to the previous generation. That equates to 72 seconds saved over 40 km at constant speed.
355g total system weight saving. The Propel Advanced SL 0 sheds 355g across the complete build. The frame alone is 45g lighter (800g vs 845g, size medium, unpainted), with further savings from the new cockpit, CADEX Max 50 wheels, and CADEX Aero tyres.
New integrated one-piece cockpit. The Contact SLR Aero Integrated handlebar/stem is shaped with flat tops, narrow hoods, and 4.8–7.3° of flare for stable handling. The SLR 0 version weighs 286g (420x100mm) and is 80g lighter than the outgoing two-piece setup.
CADEX Max 50 WheelSystem. At 1,290g with tape and valves, the Max 50 features integrated Super Aero carbon spokes, a 48-tooth ratchet hub with ceramic bearings, and a 22.4mm inner rim width. It saves 2.18 watts of aero drag over the outgoing CADEX Ultra 50 and improves rear-wheel transmission stiffness-to-weight by 14.3%.
25% more rear-end compliance. A reengineered seat tube, chainstays, and Vector integrated seatpost smooth out road vibrations for less fatigue on long rides. Front-end compliance improves by 12.8% through the fork and integrated cockpit.
32mm tyre clearance. All models accommodate tyres up to 32mm, allowing riders to choose higher-volume rubber for reduced rolling resistance and improved comfort across varied road surfaces.
Six frame sizes. The range spans XS through XL across all three model tiers, with geometry tailored for each platform.
The Bottom Line
The fourth-generation Propel is a comprehensive update rather than a revolution, but the cumulative gains are substantial. An 18.4-watt total system advantage is a meaningful difference on any ride, and the improved compliance should make this a more versatile race bike than its predecessor. For South African riders who want an aero road bike that can handle everything from flat crits to long days on imperfect roads, the new Propel looks like a strong contender.
Local Pricing and Availability
The following models and colours will be available in South Africa:
| Model | Colour | RRSP |
| Propel Advanced Pro 0 Di2 Dura-Ace | Supernova Grey | TBC |
| Propel Advanced Pro 0 Di2 Ultegra | Abyss Teal & Obsidian Pulse | R139 990,00 |
| Propel Advanced Pro 1 | Cryo Silver | R99 990,00 |
| Propel Advanced 1 | Carbon | R89 999,00 |
| Propel Advanced 2 | White & Mach Blue | R59 990,00 |
| Propel Advanced Pro Frameset | Glacier Teal | TBC |
Selected models will be on display the Cape Town Cycle Tour Expo.
To learn more head to giant-bicycles.co.za or visit your nearest Giant dealer.
