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Factor OSTRO VAM vs Specialized S-Works Tarmac SL9
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 Factor OSTRO VAM starts €2,600 cheaper (€11,399 vs €13,999 for the Specialized S-Works Tarmac SL9).
- Our verdict scores the Specialized S-Works Tarmac SL9 higher overall: 80/100 vs 77/100.
Factor OSTRO VAM
Specialized S-Works Tarmac SL9
| FactorOSTRO VAM | SpecializedS-Works Tarmac SL9 | |
|---|---|---|
| Overview | ||
| Brand | Factor | Specialized |
| Build | OSTRO VAM SRAM Red w/ Power Meter | S-Works Tarmac SL9 - Shimano Dura-Ace Di2 |
| Build notes | Barstem width and stem length, crank length, seatpost setback, frame colour and wheel decal colour are chosen at order. Prisma custom paint costs USD 600 extra. | Colour: Satin Carbon (US). Weight of a painted production bike as pictured. |
| Price (MSRP) | €13,699$12,599€13,699 | €13,999$13,500£11,999 |
| Bike weight | — | 6.6 kg14.6 lb |
| Weight measured on size | — | 56 |
| Model year | 2024 | 2027 |
| Generation | 2nd generation | SL9 |
| Launched | 2024-02 | 2026-06 |
| Discipline | Aero road | Aero road |
| UCI legal | Not stated | Not stated |
| Verdict (out of 100) | ||
| Overall score | 77 | 80 |
| Aero | 84 | 87 |
| Frame | 92 | 95 |
| Components | 90 | 94 |
| Fit | 86 | 82 |
| Practicality | 66 | 72 |
| Price | 44 | 27 |
| Weight | — | 100 |
| Frame & fork | ||
| Frame material | Carbon (TeXtreme, Toray and Nippon Graphite pitch-based fibre) | FACT 12r Carbon |
| Fork material | Carbon; OSTRO wide-stance fork | S-Works FACT 12r Carbon (Flow Fork) |
| Frame weight | 820 g28.9 oz | 687 g24.2 oz |
| Frameset weight | — | 1,390 g3.06 lb |
| Weight measured on | Size 54, painted (Factor launch press release); Factor's current spec sheet lists 900 g | Frame 687 g as stated by Specialized; frameset (frame, fork, headset bearings, S-Works Rapide Post) 1.39 kg in size 56, painted production frame |
| Max system weight | — | 125 kg275.6 lb |
| Frame sizes | 45, 49, 52, 54, 56, 58, 61 | 44, 49, 52, 54, 56, 58, 61 |
| Colours | Icon Blue, Geometric, White Chrome, Gloss Chrome, Black, Arctic Chrome, Terracotta Orange; custom Prisma paint at extra cost | Satin Carbon; Satin Silver Dust; Gloss Ruby Metallic; Gloss Dolomite Metallic; Gloss Carbon; Gloss Vivid Red / Tarmac Black; RTP Raw Carbon; Made in Racing Red (LTD); Gloss Metallic White Silver (LTD); team replica paints (varies by build and region) |
| Also available as | — | Tarmac SL9 S-Level (FACT 10r frame with FACT 12r fork), Expert and Comp builds; S-Works LTD and team replica editions |
| Compatibility & standards | ||
| Brake type | Disc, max rotor 160 mm front and rear | Hydraulic disc, flat mount |
| Max rotor size | 160 mm | 160 mm |
| Wheel size | 700c | 700c |
| Max tire width | 32 mm | 32 mm |
| Bottom bracket standard | T47A (CeramicSpeed T47A aluminium cups; bearings for DUB, 24 mm or Ultra-Torque spindles) | BSA threaded, 68 mm |
| Front axle | 12x100 thru-axle | 12x100 mm thru-axle |
| Rear axle | 12x142 thru-axle | 12x142 mm thru-axle (UDH dropout) |
| Drivetrain compatibility | Electronic only, max chainring 54T | 1x and 2x; Shimano Di2 (wired routing) and SRAM AXS. 2x chainrings: Shimano 34-42 / 50-55T, SRAM 35-41 / 48-54T; 1x 46-54T. Cassettes: Shimano 11-36 max, SRAM 10-46 max. |
| Mechanical shifting possible | No | — |
| 1x compatible | — | Yes |
| Max chainring | 54T | 55T |
| Front derailleur mount | — | Removable braze-on hanger; cover for 1x |
| Cable routing | Internal | Internal |
| Electronic battery location | Inside the seat tube, fitted from behind the bottom bracket (no need to remove the seatpost) | — |
| Hydration & storage | ||
| Bottle mounts | 2 | 2 |
| Bottle mount locations | Down tube and seat tube, with location-specific Black Inc aero bottle cages included | Down tube and seat tube |
| Fit & adjustability | ||
| Cockpit | One-piece bar and stem (Black Inc Integrated Aero Barstem) | One-piece bar and stem (Roval Rapide Cockpit) on S-Works builds |
| Seatpost type | OSTRO VAM aero seatpost, 15 mm wide, 0 or 20 mm setback; pusher-type clamp at the back of the seat tube | S-Works Rapide Post, FACT carbon, D-shaped (35.9 x 18.4 mm), 15 mm offset, integrated wedge |
| Fit notes | The barstem is chosen at order in 36, 38, 40 or 42 cm widths and 80 to 140 mm stem lengths (10 mm steps), with 80 mm reach and 120 mm drop; the drops flare by 30 mm. Factor also offers the Integrated Aero Barstem with Extensions (AB03) as an upgrade. Saddle rail clamps take 7x7 and 7x9 rails. A 45 cm size was added and the seat-tube angle is 0.5° steeper than before. | Seven sizes from 44 to 61 cm with the same performance targets for every size. Stock bar width and stem length change with size (380 mm and 75 mm on 44-49 up to 420 mm and 110 mm on 58-61). The user manual also lists a separate Rapide stem (31.8 mm bar clamp) with Expert Shallow Bend handlebars; headset spacers up to 35 mm. |
| Aerodynamics | ||
| Manufacturer aero claims | 70 g less drag (a 7 W saving) than the previous OSTRO VAM frame; Factor says it outperforms its rivals in the wind tunnel | Specialized calls it the most aerodynamic road race bike it has tested and claims 4 W less drag; the Speed Sniffer head tube is 4 mm narrower for a 10% smaller frontal area. Specialized measures it by 'Time to Finish' over simulated race courses. |
| Testing method | CFD simulations of dozens of head tube profiles (Rapid Iterative Design), then rapid prototypes verified in the wind tunnel and real-world testing | Specialized Win Tunnel with a 6th-generation moving-leg mannequin, plus race-course simulations |
| Tube profile | Airfoil-type profile along the frame's waterline; 15 mm wide seatpost shaped for the airflow off the rider's legs | Speed Sniffer head tube, dropped down tube, Win Fin rear, twisted-blade Flow Fork, deep S-Works Rapide Post |
| Travel, maintenance & warranty | ||
| Headset bearings | 1-1/8 in upper and 1-3/8 in lower bearings | CeramicSpeed SLT bearings, 49.5 mm OD x 40.5 mm ID x 6.5 mm, 45° (top and bottom); 28.6 mm steerer |
| Derailleur hanger | — | UDH (SRAM Universal Derailleur Hanger) |
| Maintenance | The threaded T47 bottom bracket takes CeramicSpeed bearings. The Di2 battery is reached from behind the bottom bracket rather than through the seatpost, so the saddle height isn't disturbed. | Front rotor 160 mm only, rear 140 or 160 mm. The user manual lists tubeless compatibility as 'Only S-Works (OE spec)'. No rack, fender, bag or kickstand mounts; 2.3 kg seat-bag limit. |
| Proprietary parts | One-piece Black Inc barstem, OSTRO VAM seatpost and clamp, location-specific bottle cages | Roval Rapide one-piece cockpit, S-Works Rapide seatpost and wedge, custom headset bearings |
| Frame warranty | Limited lifetime warranty | — |
| Sold via | Direct from factorbikes.com and through retailers | Specialized retailers and specialized.com |
| Drivetrain | ||
| Groupset | SRAM Red eTap AXS | Shimano Dura-Ace Di2 R9200 |
| Launched | 2019 · replaced by SRAM Red AXS E1 (2024) | 2021 · current generation |
| Speeds | 12-speed | 12-speed |
| Electronic | Yes | Yes |
| Wireless | Yes | — |
| Drivetrain | 2x | 2x |
| Shifters | — | Shimano Dura-Ace Di2 R9270 |
| Crankset | SRAM Red AXS Power Meter | Shimano Dura-Ace R9200 |
| Chainrings | 48/35 | 52/36 |
| Crank length | 165 / 170 / 172.5 (chosen at order) | — |
| Crank lengths available | — | 165 mm (44-52), 170 mm (54-56), 172.5 mm (58-61) |
| Power meter | SRAM Red AXS Power Meter | 4iiii Precision Pro |
| Measurement | — | Dual-sided |
| Bottom bracket | — | CeramicSpeed BB Alpha |
| Standard | — | BSA threaded, Shimano |
| Front derailleur | — | Shimano Dura-Ace Di2 R9250 |
| Notes | — | Braze-on |
| Rear derailleur | — | Shimano Dura-Ace Di2 R9250 |
| Cassette | SRAM Red AXS | Shimano Dura-Ace R9200 |
| Range | 10-33 | 11-34 |
| Speeds | 12-speed | 12-speed |
| Chain | — | Shimano CN-M9100 |
| Notes | — | XTR M9100 chain with quick link |
| Brakes | ||
| Brake calipers | — | Shimano Dura-Ace BR-R9270 |
| Type | — | Hydraulic disc |
| Rotors | 160 mm rotors | — |
| Front rotor | 160 mm | — |
| Rear rotor | 160 mm | — |
| Wheels & tires | ||
| Wheelset | Black Inc 48|58 | Roval Rapide CLX III |
| Front rim depth | 48 mm | 51 mm |
| Rear rim depth | 58 mm | 48.5 mm |
| Internal rim width | 23 mm | 21 mm |
| Material | Carbon rims, carbon spokes | Carbon |
| Tubeless ready | — | Yes |
| Rim bead | Mini hook | — |
| Hubs | — | Roval LF18F 18H front, LF19-R 24H rear, with Sinc ceramic bearings |
| Spokes | — | Roval by ARRIS composite aero spokes with Ti end fittings |
| Notes | Black or silver decals, chosen at order | — |
| Tires | — | Specialized Cotton TLR |
| Tire width | — | 30 mm |
| Notes | — | Specialized also lists 700x25-35 mm TPU inner tubes |
| Cockpit | ||
| Handlebar | Black Inc Integrated Aero Barstem | Roval Rapide Cockpit |
| Type | One-piece bar and stem | One-piece bar and stem |
| Integrated stem | Yes | Yes |
| Widths available | 36, 38, 40, 42 cm | 380 mm (44-54), 400 mm (56), 420 mm (58-61) as fitted by size |
| Bar reach | 80 mm | — |
| Bar drop | 120 mm | — |
| Material | — | Carbon |
| Notes | Stem length 80-140 mm in 10 mm steps, chosen at order; drops flare by 30 mm | Stem length 75 mm (44-49), 90 mm (52), 100 mm (54-56), 110 mm (58-61); accessory mount compatible with Bar Fly 4 adapters |
| Headset | — | CeramicSpeed SLT |
| Saddle & seatpost | ||
| Saddle | — | Specialized S-Works Power with Mirror |
| Widths available | — | 155 mm (44-52), 143 mm (54-61) |
| Seatpost | Factor OSTRO VAM Seatpost | Specialized S-Works Rapide Post |
| Offset / setback | 0 mm or 20 mm setback, 350 mm long | 15 mm |
| Material | Carbon | FACT carbon |
| Notes | — | 300 mm long (44-52), 380 mm (54-61); integrated wedge binder |
| Bar tape | — | Supacaz Super Sticky Kush |
| Included extras | ||
| Bottle cages | Black Inc Aero Integrated Bottle Cages | — |
| Geometry (smallest – largest size) | ||
| Sizes | 45, 49, 52, 54, 56, 58, 61 | 44, 49, 52, 54, 56, 58, 61 |
| Stack | 502–611 mm19.8–24.1″ | 501–612 mm19.7–24.1″ |
| Reach | 360–409 mm14.2–16.1″ | 366–408 mm14.4–16.1″ |
| Seat tube angle | 73.5–75.5° | 73–75.5° |
| Head tube angle | 71.1–73.3° | 70.5–74° |
| Head tube length | — | 99–204 mm3.9–8″ |
| Effective top tube | — | 496–595 mm19.5–23.4″ |
| Seat tube length | 432–554 mm17–21.8″ | 433–545 mm17–21.5″ |
| Chainstay | 405–410 mm15.9–16.1″ | 410 mm16.1″ |
| Wheelbase | 969–1,022 mm38.1–40.2″ | 970–1,013 mm38.2–39.9″ |
| BB drop | 70–72 mm2.8–2.8″ | 72–74 mm2.8–2.9″ |
| BB height | — | 266–268 mm10.5–10.6″ |
| Fork length | — | 370 mm14.6″ |
| Fork offset | 43–57 mm1.7–2.2″ | 44–47 mm1.7–1.9″ |
| Trail | 58–58.6 mm2.3–2.3″ | 52–71 mm2–2.8″ |
| Front centre | — | 567–609 mm22.3–24″ |
| Standover | 726–840 mm28.6–33.1″ | 722–833 mm28.4–32.8″ |
| Wheel size | — | 700c |
| Crank length | — | 165–172.5 mm6.5–6.8″ |
| Stem length | — | 75–110 mm3–4.3″ |
| Handlebar width | — | 380–420 mm15–16.5″ |
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).