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Ribble Ultra-Aero SL vs Storck Aerfast.4 Comp
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
- Our verdict scores the Storck Aerfast.4 Comp higher overall: 72/100 vs 70/100.
- The Ribble Ultra-Aero SL comes in 5 sizes, the Storck Aerfast.4 Comp in 6.
Ribble Ultra-Aero SL
Storck Aerfast.4 Comp
| RibbleUltra-Aero SL | StorckAerfast.4 Comp | |
|---|---|---|
| Overview | ||
| Brand | Ribble | Storck |
| Build | Ultra-Aero SL Ultegra Di2 | Aerfast.4 Comp 105 (11-speed) |
| Build notes | Regular price; Ribble's end-of-season sale, ending 2 November 2026, offered it at £3,599 / $5,015. Ribble doesn't list the crankset. | Colour Matt Black; 11-speed Shimano 105 R7000 with DT Swiss PR 1600 Spline 32 alloy wheels. MSRP €3,399; Storck showed it reduced to €2,999 on 2 Nov 2026. Price from Storck's own web shop (EUR only). No power meter. |
| Price (MSRP) | $6,660$6,660£4,449 | €3,399€3,399€3,399 |
| Bike weight | 8.4 kg18.5 lb | — |
| Weight measured on size | M | — |
| Model year | 2026 | 2026 |
| Generation | — | Aerfast.4 (fourth generation) |
| Launched | — | 2021 |
| Newer generation | — | Aerfast.5 (2024) |
| Discipline | Aero road | Aero road |
| UCI legal | Yes | Yes |
| Verdict (out of 100) | ||
| Overall score | 70 | 72 |
| Aero | 76 | 85 |
| Frame | 60 | 64 |
| Components | 56 | 58 |
| Fit | 66 | 72 |
| Practicality | 72 | 58 |
| Price | 93 | 97 |
| Weight | 68 | — |
| Frame & fork | ||
| Frame material | Carbon (T1000 and T800 monocoque) | Carbon (CFR/UD), Comp grade |
| Fork material | Carbon | — |
| Frame weight | 1,200 g2.65 lb | 950 g33.5 oz |
| Fork weight | 580 g20.5 oz | 500 g17.6 oz |
| Frameset weight | — | 1,900 g4.19 lb |
| Weight measured on | Ribble's figures | Storck's 'from' weights on its Aerfast.4 Platinum and Pro frameset pages (frame, fork, one-piece cockpit; frameset includes seatpost and headset); not split by grade or size |
| Max system weight | — | 120 kg264.6 lb |
| Frame sizes | XS, S, M, L, XL | XS, S, M, L, XL |
| Colours | — | Matt Black |
| Also available as | Ultra-Aero SL R: same design with a lighter, higher-grade layup and the Ultra-Aero bar | Aerfast.4 Platinum, Pro, Comp and Red Edition (frame classes of the same design, same geometry); succeeded by the Aerfast.5 |
| UCI frame approval | — | On the UCI list of approved framesets as 'AERFAST.3 / AERFAST.4' (code STOR-AEF), approved 8 Feb 2023 in sizes XS-XXL (6) (UCI list version 2026.10.02); the list doesn't distinguish the grades |
| Compatibility & standards | ||
| Brake type | Hydraulic disc | Hydraulic disc, flat mount (160 mm rotors front and rear as built) |
| Wheel size | 700c | — |
| Max tire width | — | 28 mm |
| Bottom bracket standard | BSA 68 mm threaded | Press-fit, 41 mm bearing bore x 86.5 mm |
| Cable routing | — | Internal through the one-piece cockpit |
| Fit & adjustability | ||
| Cockpit | One-piece bar and stem (Ribble RI-2 carbon) | One-piece Storck RBSU Aerfast.4 bar and stem, one size per frame size |
| Seatpost type | Ribble Ultra-Aero SL R/SL setback carbon seatpost | Storck Aerfast.4 carbon aero seatpost |
| Fit notes | — | Each frame size comes with one cockpit size, from 380 mm bar / 90 mm stem (XS) to 440 / 120 mm (XXL). Storck says a computer mount and triathlon extensions can be retrofitted, and lists its TT kit as compatible with the Aerfast.4. |
| Aerodynamics | ||
| Manufacturer aero claims | — | Storck says the Aerfast.4 measured 199 W at 45 km/h in TOUR's wind-tunnel test; TOUR's own figures were 201 W for the Pro Disc and 202 W for the Comp Disc |
| Testing method | — | Wind tunnel |
| Tube profile | — | 80 mm wide aero fork with a camtail trailing edge |
| Travel, maintenance & warranty | ||
| Proprietary parts | — | RBSU Aerfast.4 one-piece cockpit, Aerfast.4 seatpost and headset |
| Sold via | — | Direct from Storck's web shop and Storck stores |
| Drivetrain | ||
| Groupset | Shimano Ultegra Di2 R8100 | Shimano 105 R7000 |
| Launched | 2021 · current generation | 2018 · replaced by Shimano 105 R7100 (2023) |
| Speeds | 12-speed | 11-speed |
| Electronic | Yes | No |
| Drivetrain | 2x | 2x |
| Shifters | Shimano Ultegra Di2 ST-R8170 | Shimano 105 R7000 |
| Notes | — | Mechanical shift and hydraulic brake levers |
| Crankset | — | Shimano 105 R7000 |
| Chainrings | — | 50/34 |
| Crank lengths available | — | 170 mm (XS-S), 172.5 mm (M-L), 175 mm (XL-XXL) |
| Bottom bracket | Shimano BB-R60 | Storck Press-fit 41 x 86.5 mm |
| Standard | BSA 68 mm threaded | Press-fit, 41 mm bearing bore x 86.5 mm |
| Front derailleur | Shimano Ultegra Di2 R8150 | — |
| Rear derailleur | Shimano Ultegra Di2 R8150 | Shimano 105 R7000 |
| Cassette | Shimano Ultegra R8101 | Shimano 105 R7000 |
| Range | 11-34 | 11-30 |
| Speeds | 12-speed | 11-speed |
| Chain | Shimano CN-M8100 | Shimano CN-HG601 |
| Brakes | ||
| Brake levers | Shimano Ultegra Di2 ST-R8170 | — |
| Brake calipers | — | Shimano 105 |
| Type | — | Hydraulic disc, flat mount |
| Notes | — | 160 mm rotors front and rear |
| Rotors | Shimano RT-CL800 | — |
| Front rotor | 160 mm | — |
| Wheels & tires | ||
| Wheelset | Mavic Cosmic S 42 | DT Swiss PR 1600 Spline 32 |
| Front rim depth | — | 32 mm |
| Rear rim depth | — | 32 mm |
| Material | Carbon | Aluminium |
| Tires | Vittoria Corsa N.EXT TLR | Continental Grand Prix TR |
| Tire width | 30 mm | 25 mm |
| Cockpit | ||
| Handlebar | Ribble RI-2 Carbon Integrated | Storck RBSU Aerfast.4 |
| Type | One-piece bar and stem | One-piece bar and stem |
| Integrated stem | Yes | Yes |
| Widths available | — | 380 mm / 90 mm stem (XS), 400/100 (S), 420/100 (M-L), 420/110 (XL), 440/120 (XXL) |
| Material | Carbon | — |
| Headset | — | Storck Aerfast.4 integrated headset |
| Saddle & seatpost | ||
| Saddle | Selle Italia SLR Advan Superflow L3 | Selle San Marco Shortfit 2.0 |
| Seatpost | Ribble Ultra-Aero SL R/SL Setback Carbon | Storck Aerfast.4 Carbon |
| Material | Carbon | Carbon |
| Bar tape | — | Storck Microfibre |
| Notes | — | Black |
| Geometry (smallest – largest size) | ||
| Sizes | XS, S, M, L, XL | XS, S, M, L, XL, XXL |
| Rider height min | 160–185 cm5′3″–6′1″ | 152–188 cm5′0″–6′2″ |
| Rider height max | 165–191 cm5′5″–6′3″ | 166–190 cm5′5″–6′3″ |
| Stack | 506–583 mm19.9–23″ | 482–576 mm19–22.7″ |
| Reach | 379–410 mm14.9–16.1″ | 362.5–418 mm14.3–16.5″ |
| Seat tube angle | 73.3–75° | 73° |
| Head tube angle | 72–73.5° | 70–72° |
| Head tube length | 105–180 mm4.1–7.1″ | 85–170 mm3.3–6.7″ |
| Effective top tube | 515–585 mm20.3–23″ | 510–595 mm20.1–23.4″ |
| Seat tube length | 470–560 mm18.5–22″ | 458–583 mm18–23″ |
| Chainstay | 410 mm16.1″ | 410 mm16.1″ |
| Wheelbase | 975–1,014 mm38.4–39.9″ | — |
| BB drop | 69 mm2.7″ | — |
| Fork offset | 45–53 mm1.8–2.1″ | — |
| Front centre | 518–613 mm20.4–24.1″ | — |
| Wheel size | 700c | — |
| Crank length | 165–172.5 mm6.5–6.8″ | 170–175 mm6.7–6.9″ |
| Stem length | 80–110 mm3.1–4.3″ | 90–120 mm3.5–4.7″ |
| Handlebar width | 380–420 mm15–16.5″ | 380–440 mm15–17.3″ |
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).