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Argon 18 Nitrogen Pro vs Cervélo S5
Pick up to 4 bikes. Rows line up component by component. Highlighted rows differ, and green marks the best value where lower or higher is clearly better.
Key differences
- The Cervélo S5 starts €996 cheaper (€9,999 vs €10,995 for the Argon 18 Nitrogen Pro).
- Our verdict scores the Cervélo S5 higher overall: 82/100 vs 81/100.
- The Cervélo S5's lightest build is 0.21 kg lighter (6.74 kg vs 6.95 kg).
- Tire clearance: up to 32 mm on the Argon 18 Nitrogen Pro vs 34 mm on the Cervélo S5.
Argon 18 Nitrogen Pro
Cervélo S5
| Argon 18Nitrogen Pro | CervéloS5 | |
|---|---|---|
| Overview | ||
| Brand | Argon 18 | Cervélo |
| Build | Nitrogen Pro SRAM Red AXS | S5 Red AXS |
| Build notes | Colour Aurora Charcoal. Argon 18's white paper gives 6.95 kg for this build in size M (painted, with Vittoria Corsa Pro tyres and TPU tubes). | Colours Five Black and Reef Blue (Five Black only in the UK). In the US Cervélo also lists the same build in a 'Maps LTD' paint limited to 650 frames, at the same price. Cervélo doesn't state the size of the claimed weight. |
| Price (MSRP) | €13,995$14,499£13,000 | €13,999$14,500£12,750 |
| Bike weight | 6.95 kg15.3 lb | 7.32 kg16.1 lb |
| Weight measured on size | M | — |
| Model year | 2026 | 2027 |
| Generation | 2025 relaunch | 2025 version |
| Launched | 2025-09 | 2025-07 |
| Discipline | Aero road | Aero road |
| UCI legal | Yes | Yes |
| Verdict (out of 100) | ||
| Overall score | 81 | 82 |
| Aero | 92 | 95 |
| Frame | 86 | 88 |
| Components | 90 | 90 |
| Fit | 80 | 86 |
| Practicality | 72 | 62 |
| Price | 47 | 53 |
| Weight | 97 | 100 |
| Frame & fork | ||
| Frame material | Carbon (Nitrogen Pro layup) | Carbon |
| Fork material | Carbon | Carbon (Bayonet S5 fork) |
| Frameset weight | — | 2,280 g5.03 lb |
| Weight measured on | Argon 18 quotes a frame under 950 g and a fork under 415 g (size M, painted) | Frameset including HB19 one-piece cockpit and SP34 seatpost, as listed by Cervélo (size not stated) |
| Frame sizes | XXS, XS, S, M, L, XL | 48, 51, 54, 56, 58, 61 |
| Colours | Aurora Charcoal | Five Black, Reef Blue, Maps Ltd; Infrared on the frameset (varies by build and region) |
| Also available as | Nitrogen, a lower-grade carbon version of the same platform | — |
| UCI frame approval | Approved 27 May 2025 as 'NITROGEN PRO' (frame and fork), sizes XXS-XL (6), code AR18-004 (UCI list version 2026.10.02) | — |
| Compatibility & standards | ||
| Brake type | Hydraulic disc | Hydraulic disc, flat mount |
| Max rotor size | 160 mm | 160 mm |
| Wheel size | — | 700c |
| Max tire width | 32 mm | 34 mm |
| Bottom bracket standard | T47 threaded, 85.5 mm shell | BBright |
| Front axle | 12 mm thru-axle (M12 x 1.5, 119 mm) | 12x100 thru-axle (Cervélo Aero Thru Axle, M12x1.5) |
| Rear axle | 12x142 mm thru-axle (M12 x 1.0, 167.5 mm) | 12x142 thru-axle (Cervélo Aero Thru Axle, M12x1.0, UDH) |
| Drivetrain compatibility | Electronic groupsets (the assembly guide covers wireless and wired routing only). 2x with 50-57T round chainrings (or oval of equivalent size); 1x up to 56T | Electronic and wireless groupsets only: Shimano Di2 12-speed and SRAM eTap AXS, 1x and 2x |
| Mechanical shifting possible | — | No |
| 1x compatible | Yes | Yes |
| Max chainring | 57T | — |
| Front derailleur mount | Removable front derailleur hanger; plugs fill the holes for 1x | Removable braze-on mount (Front Derailleur Mount 907); blanked off for 1x |
| Cable routing | Fully internal | — |
| Electronic battery location | On the bottom bracket cover / battery holder | Inside the down tube (Cervélo internal battery mount) |
| Hydration & storage | ||
| Bottle mounts | 2 | — |
| Bottle mount locations | Down tube and seat tube, with the included ATTEN aero cages | — |
| Fit & adjustability | ||
| Cockpit | One-piece carbon bar and stem (ATTEN CHB-01 Aero) | One-piece carbon bar and stem (Cervélo HB19) |
| Standard stem and bar possible | Yes | — |
| Seatpost type | Argon 18 Nitrogen Pro aero carbon seatpost, -20 mm setback or 'zero setback' (+10 mm forward) | Cervélo SP34 carbon aero seatpost, 0 mm or 15 mm offset |
| Fit notes | 6 sizes. The CHB-01 comes in 360 and 380 mm widths with 80-130 mm stems (12 sizes). Up to 40 mm of two-piece aero spacers fit under the bar and can be added or removed without cutting brake hoses. A regular stem can be fitted (the assembly guide covers it), and IST3 headset caps are offered for Deda Alanera RS, FSA ACR/SMR and FSA SRS cockpits. | HB19 uses Cervélo's 'Plus-Four' shape: the bar is 4 cm wider in the drops than at the hoods (e.g. 38/42 cm). Cervélo lists 19 HB19 sizes from 80 to 150 mm stem length in 36/40, 38/42 and 40/44 cm widths, and buyers can swap to another size once at no charge for the part through their retailer within 60 days. Stem spacers raise the bar 5 to 30 mm above the base position. |
| Aerodynamics | ||
| Manufacturer aero claims | Argon 18 says the Nitrogen is 24 W faster than its Sum Pro (reported by TOUR; tested with a rider). The white paper claims the CHB-01 cockpit saves 6.7 W against a standard bar and stem and 4.3 W against a Vision Metron 5D at 45 km/h (wind-averaged), the aero cages 1.1 W with bottles and 1.8 W empty, and that adding two bottles costs 0-3 W against 4-9 W on a traditional aero frame. The aero spacers cost 0.7 W per 30 mm of stack (Sum Pro: 1.4 W). | 6.3 W faster than the previous S5 (BikeRadar reports this at 50 km/h over ±15° yaw), and Cervélo says it is at least 5 W faster than competitors' bikes. The Reserve 57|64 wheels are claimed to be 3 W faster than the 52|63 at the same weight. |
| Testing method | CFD on more than 130 tube profiles and 25 fork prototypes, three wind-tunnel sessions, final tests with a pedalling rider and with mannequin legs at 45 km/h against the Sum Pro and an unnamed WorldTour aero bike. Wheels and frame were developed together with Scope. | Most of the gain is from the front end (deeper fork legs and head tube, one-piece cockpit); Cervélo says the asymmetric seat tube and matching asymmetric rear rim also contribute. |
| Tube profile | Truncated NACA-based profiles; off-axis head tube with the steerer set back from the leading edge; wide-stance fork; dropped seat stays | — |
| Travel, maintenance & warranty | ||
| Headset bearings | IST3 (CeramicSpeed SLT bearings on the complete bikes) | FSA IS2, 1-1/8 in top and 1-3/8 in bottom, 36° x 45° (Super Light bearings on the top builds) |
| Derailleur hanger | UDH (SRAM Universal Derailleur Hanger), standard or direct-mount version | UDH (SRAM Universal Derailleur Hanger); Cervélo Derailleur Hanger V2 in standard or Shimano Direct Mount versions |
| Maintenance | — | Every front caliper needs Cervélo's Front Brake Mounting Plate 004; the front rotor must be 160 mm, the rear 140 or 160 mm. The fork uses a tension-rod steerer system. |
| Proprietary parts | ATTEN CHB-01 cockpit and aero spacers, Nitrogen seatpost and clamp (not shared with the Sum), ATTEN aero cages, BB cover/battery holder, thru-axles | HB19 one-piece cockpit, Bayonet fork with tension rod, SP34 seatpost and clamp, aero thru-axles, front brake mounting plate |
| Frame warranty | — | Limited lifetime warranty on the frame for the original owner (frames bought from 1 Sept 2025, excluding paint and decals); forks, carbon bars, stems and seatposts also lifetime |
| Sold via | Through Argon 18 dealers | Through Cervélo retailers |
| Drivetrain | ||
| Groupset | SRAM Red AXS E1 | SRAM Red AXS E1 |
| Launched | 2024 · current generation | 2024 · current generation |
| Speeds | 12-speed | 12-speed |
| Electronic | Yes | Yes |
| Wireless | Yes | Yes |
| Drivetrain | 2x | 2x |
| Shifters | SRAM Red AXS E1 | SRAM Red AXS E1 |
| Notes | Combined shift and hydraulic brake levers | Combined shift and hydraulic brake levers |
| Crankset | SRAM Red AXS E1 Power Meter | SRAM Red AXS E1 Power Meter |
| Chainrings | 48/35 | 50/37 |
| Crank lengths available | 165 mm (XXS-XS), 170 mm (S-M), 172.5 mm (L-XL) | 160 mm (48), 165 mm (51), 170 mm (54-56), 172.5 mm (58-61) |
| Spindle | — | DUB |
| Power meter | SRAM Red AXS E1 Power Meter | SRAM Red AXS E1 Power Meter |
| Launched | 2024 · current generation | 2024 · current generation |
| Type | Integrated in crankset | Integrated in crankset |
| Bottom bracket | CeramicSpeed T47 DUB Coated | SRAM DUB Ceramic |
| Standard | T47 threaded | BBright |
| Front derailleur | SRAM Red AXS E1 | SRAM Red AXS E1 |
| Rear derailleur | SRAM Red AXS E1 | SRAM Red AXS E1 |
| Cassette | SRAM Red XG-1290 E1 | SRAM Red E1 |
| Range | 10-33 | 10-33 |
| Speeds | 12-speed | 12-speed |
| Chain | SRAM Red | SRAM Red E1 |
| Brakes | ||
| Rotors | SRAM Paceline X | SRAM Paceline X |
| Front rotor | 160 mm | — |
| Rear rotor | 140 mm | — |
| Mount | Center Lock | Center Lock |
| Wheels & tires | ||
| Wheelset | ATTEN x Scope Artech 6.A+ | Reserve 57TA (front) / 64TA (rear) |
| Front rim depth | — | 57 mm |
| Rear rim depth | — | 64 mm |
| Material | Carbon | Carbon |
| Tubeless ready | — | Yes |
| Hubs | — | DT Swiss 180, Center Lock |
| Spokes | — | 24 front, 24 rear |
| Recommended tire widths | Optimised for 30 mm tyres | — |
| Freehub options | — | SRAM XDR |
| Notes | Co-developed with Scope for the Nitrogen Pro, with a rim shape re-optimised from Scope's Artech 6.A | — |
| Tires | Vittoria Corsa Pro TLR | Vittoria Corsa Pro TLR G2.0 |
| Tire width | 30 mm | 29 mm |
| Cockpit | ||
| Handlebar | ATTEN CHB-01 Aero | Cervélo HB19 |
| Type | One-piece carbon bar and stem | One-piece bar and stem |
| Integrated stem | Yes | Yes |
| Widths available | 360 or 380 mm, each with 80-130 mm stems (12 sizes) | 36/40, 38/42 or 40/44 cm (hoods/drops); stock width by frame size |
| Material | Carbon | Carbon |
| Weight | 320 g11.3 oz | — |
| Notes | Stock size by frame: 360 x 80 (XXS), 360 x 90 (XS-S), 380 x 100 (M), 380 x 110 (L), 380 x 120 (XL). Integrated computer mount with Garmin and Wahoo inserts and 3-12° tilt shims. Weight for 380 x 100 mm. | — |
| Headset | CeramicSpeed SLT (IST3) | FSA SL IS2 1-1/8 in / 1-3/8 in |
| Saddle & seatpost | ||
| Saddle | Repente Quasar CR 2.0 | Fizik Arione R1 Light |
| Seatpost | Argon 18 Nitrogen Pro | Cervélo SP34 |
| Offset / setback | -20 mm setback (a 'zero setback' version, 10 mm further forward, is available) | 0 mm (48-58), 15 mm (61) |
| Material | Carbon | Carbon |
| Weight | 160 g5.6 oz | — |
| Notes | Weight includes clamp | — |
| Bar tape | Ciclovation Leather Touch Tornado Gloss | — |
| Included extras | ||
| Pedals | — | None included |
| Bottle cages | ATTEN Aero cages (down tube and seat tube) | — |
| Geometry (smallest – largest size) | ||
| Sizes | XXS, XS, S, M, L, XL | 48, 51, 54, 56, 58, 61 |
| Rider height min | — | 160–192 cm5′3″–6′4″ |
| Rider height max | — | 160–192 cm5′3″–6′4″ |
| Stack | 486–607 mm19.1–23.9″ | 496–608 mm19.5–23.9″ |
| Reach | 370–409 mm14.6–16.1″ | 367–409 mm14.4–16.1″ |
| Seat tube angle | 72.5–75° | 73° |
| Head tube angle | 71.2–73° | 71–73.5° |
| Head tube length | 81–192 mm3.2–7.6″ | 64–173 mm2.5–6.8″ |
| Effective top tube | 502–601 mm19.8–23.7″ | 520–595 mm20.5–23.4″ |
| Seat tube length | 395–595 mm15.6–23.4″ | — |
| Chainstay | 410 mm16.1″ | 405 mm15.9″ |
| Wheelbase | 967–1,020 mm38.1–40.2″ | 973–1,013 mm38.3–39.9″ |
| BB drop | 71–79 mm2.8–3.1″ | 69.5–74.5 mm2.7–2.9″ |
| Fork length | 376 mm14.8″ | — |
| Fork offset | 45–49 mm1.8–1.9″ | 46.5–58.5 mm1.8–2.3″ |
| Trail | — | 55.6 mm2.2″ |
| Front centre | — | 579–617 mm22.8–24.3″ |
| Standover | 682–848 mm26.9–33.4″ | 712–822 mm28–32.4″ |
| Saddle height min | 565–765 mm22.2–30.1″ | — |
| Saddle height max | 715–915 mm28.1–36″ | — |
| Wheel size | — | 700c |
| Crank length | 165–172.5 mm6.5–6.8″ | 160–172.5 mm6.3–6.8″ |
| Stem length | 80–120 mm3.1–4.7″ | 80–120 mm3.1–4.7″ |
| Handlebar width | 360–380 mm14.2–15″ | 360–400 mm14.2–15.7″ |
Geometry overlay
Pick a size for each bike to see frames and arm-pad ranges on top of each other.
Drawn to scale (how to read it).