Factor has launched its new gravel race bike, the Ostro Gravel, with the onus set squarely on moving fast whether you’re tackling Unbound or riding on tarmac.
The Ostro Gravel's carbon frame features aero optimisations aimed at making it competitive at the front of races such as Unbound, yet incorporating wide 45mm tyre clearance (on 700c wheels) to suit a wider range of gravel riding applications and enough crossover ability for use on the road.
The bike's aggressive geometry is said to “reflect racing use”, while it also comes prepared for the rigours of the diverse gravel discipline, with additional attachment points for bags, boxes, tools and bottles.
There are six complete SRAM-equipped builds, all with new hookless Black Inc Thirty-Four wheels, a Black Inc integrated cockpit, CeramicSpeed bearings in the bottom bracket and a CeramicSpeed headset.
Customers will also be able to choose from a frameset or frameset-plus-wheelset package, enabling the use of either Shimano or Campagnolo groupsets.
Available from the end of September, prices start from £7,060 / $8,199 / €8,120 for a SRAM Force XPLR eTap-equipped bike with power meter, rising to £9,380 / $10,899 / €10,800 for a SRAM Red eTap build with power meter.
Frameset packages cost £4,730 / $5,499 / €5,450 without wheels, or £6,450 / $7,499 / €7,430 with wheels.
Built for the race
The Factor Ostro Gravel, first and foremost, is a bike designed to race at the highest levels of gravel racing.
But, with gravel being a diverse and flexible discipline, the Ostro Gravel’s design is also claimed to meet the needs of those looking to take it on the road.
The frame is made of a blend of TeXtreme and Toray carbon, interwoven with Nippon Graphite fibres, which together create what Factor calls a “strengthened layup” ready for gravel racing.
It has a 900g claimed painted weight and features broad aero tubing, not unlike that seen on the Ostro VAM all-rounder road bike.
There are broad ovalised, yet truncated head tube and down tube profiles, which are claimed to be aerodynamically optimised for gravel riding speeds.
In a gravel-race scenario, average speeds are naturally lower than in a typical road race, so ultimate wind-cheating performance at high speeds becomes less imperative.
Instead, the Ostro Gravel’s tubes are noticeably squared-off to promote aero stability in challenging conditions.
The geometry is designed to offer a stable ride, yet bring sharp handling thanks to a steeper-than-average (for a gravel bike) head tube angle, at 72.3 degrees.
Factor says it selected the head tube angle (and fork rake) with one eye firmly on giving the Ostro Gravel “crossover application” – more relaxed behaviour with gravel tyres fitted, and sharper road bike-like handling with narrower, slicker rubber.
Although exact measurements will vary between chosen tyres, those running wider, chunkier gravel-specific tyres should experience a trail in the region of 60mm, while riders with 30 to 35mm tyres fitted will see around a 57mm trail.
Elsewhere, a wheelbase of 1,029mm in a size 56cm should provide a blend of stability over rough surfaces.
Factor says the head tube angle combined with long chainstays (423mm, size 56cm) and tall stack heights (580mm, size 56cm) should offer a comfortable all-day ride.
Naturally, these angles and measurements change depending on the size you opt for, but the handling is said to be “on the faster-handling side for gravel”, yet deliver precise behaviour on more road-going tyres.
| Frame size | 49cm | 52cm | 54cm | 56cm | 58cm | 61cm |
| Stack (mm) | 515 | 535 | 555 | 580 | 605 | 625 |
| Reach (mm) | 377 | 385 | 394 | 402 | 412 | 422 |
| Rear center (mm) | 420 | 420 | 420 | 423 | 425 | 425 |
| Front center (mm) | 591 | 604 | 605 | 620 | 638 | 655 |
| Wheelbase (mm) | 999 | 1013 | 1014 | 1029 | 1047 | 1069 |
| BB drop (mm) | 76 | 76 | 74 | 74 | 74 | 74 |
| Seat tube angle (degrees) | 74.5 | 74 | 74 | 73.5 | 73.5 | 73.5 |
| Head tube angle (degrees) | 71.2 | 71.3 | 72.2 | 72.3 | 72.3 | 72.3 |
| Effective top tube (mm | 250 | 538 | 553 | 574 | 591 | 607 |
| Seat tube (mm) | 450 | 468 | 483 | 500 | 523 | 545 |
| Fork length (mm) | 400 | 400 | 400 | 400 | 400 | 400 |
| Fork offset (mm) | 56 | 56 | 50 | 50 | 50 | 50 |
| Trail (mm) | 57-62 | 57-62 | 57-61 | 57-61 | 57-61 | 57-61 |
The Ostro Gravel features a T47A threaded bottom bracket, spinning around CeramicSpeed bearings.
All-new integrated bar-stem
The Factor Ostro Gravel also sees fully internal cable routing, thanks to the new Black Inc HB02 carbon bar-stem.
The hydraulic brake hose routing passes through the handlebar and stem, and down the front of the CeramicSpeed headset through a split ring. From there, it runs down the down tube or the fork leg.
The bar itself features aero-profiled flattened tops, and a broad T-junction as the stem meets the handlebar. It’s claimed to save up to 9 watts “compared to a regular bar-stem setup”.
Black Inc – Factor’s in-house component brand – says the flared design of the drops makes finding an optimal shifter position easier.
Moreover, it could also improve hand mobility, enabling the rider to switch between riding on the hoods and in the drops more easily.
The HB02 bar-stem can also accommodate a new GoPro-style out-front computer mount, which has a secondary mounting point built in for a camera.
The fork uses a rounded 1 1/8in steerer, making a swap out to a third-party cockpit easier, if desired.
All full Ostro Gravel builds, plus the frameset and wheel bundle, come with Black Inc’s Thirty-Four carbon wheelset.
The brand says it’s designed for gravel use first and foremost, but it’s also well-suited for road riding with tubeless tyres 30mm wide and above.
Its hookless rims feature 25mm internal and 30mm external widths, are 34mm deep, and are built around Black Inc’s own hubs complete with CeramicSpeed bearings.
The claimed weight for the wheelset is 1,489g.
Factor Ostro Gravel specifications, availability and prices
The Factor Ostro Gravel is set to be available from the end of September, with prices starting from £7,060 / $8,199 / €8,120 for a full-build bike.
Factor Ostro Gravel SRAM Red + power meter
- Price: £9,380 / $10,899 / €10,800
- Frame: Factor Ostro Gravel
- Fork: Factor Ostro Wide Stance fork
- Groupset: SRAM Red eTap AXS
- Power meter: SRAM Red AXS power meter crankset
- Wheels: Black Inc Thirty-Four carbon hookless
- Tyres: Goodyear Connector Ultimate, tubeless-ready, 40mm
- Seatpost: Factor Ostro Gravel (Zero + 20mm setback)
- Handlebar/stem: Black Inc HB02
- Saddle: Selle Italia SLR Boost
Factor Ostro Gravel SRAM Red
- Price: £9,030 / $10,499 / €10,400
- Frame: Factor Ostro Gravel
- Fork: Factor Ostro Wide Stance fork
- Groupset: SRAM Red eTap AXS
- Power meter: No
- Wheels: Black Inc Thirty-Four carbon hookless
- Tyres: Goodyear Connector Ultimate, tubeless-ready, 40mm
- Seatpost: Factor Ostro Gravel (Zero + 20mm setback)
- Handlebar/stem: Black Inc HB02
- Saddle: Selle Italia SLR Boost
Factor Ostro Gravel SRAM Red XPLR + power meter
- Price: £8,430 / $9,799 / €9,710
- Frame: Factor Ostro Gravel
- Fork: Factor Ostro Wide Stance fork
- Groupset: SRAM Red eTap AXS XPLR
- Power meter: SRAM Red AXS power meter crankset
- Wheels: Black Inc Thirty-Four carbon hookless
- Tyres: Goodyear Connector Ultimate, tubeless-ready, 40mm
- Seatpost: Factor Ostro Gravel (Zero + 20mm setback)
- Handlebar/stem: Black Inc HB02
- Saddle: Selle Italia SLR Boost
Factor Ostro Gravel SRAM Force + power meter
- Price: £7,570 / $8,799 / €8,720
- Frame: Factor Ostro Gravel
- Fork: Factor Ostro Wide Stance fork
- Groupset: SRAM Force eTap AXS
- Power meter: SRAM Force AXS power meter crankset
- Wheels: Black Inc Thirty-Four carbon hookless
- Tyres: Goodyear Connector Ultimate, tubeless-ready, 40mm
- Seatpost: Factor Ostro Gravel (Zero + 20mm setback)
- Handlebar/stem: Black Inc HB02
- Saddle: Selle Italia SLR Boost
Factor Ostro Gravel SRAM Force
- Price: £7,400 / $8,599 / €8,520
- Frame: Factor Ostro Gravel
- Fork: Factor Ostro Wide Stance fork
- Groupset: SRAM Force eTap AXS
- Power meter: No
- Wheels: Black Inc Thirty-Four carbon hookless
- Tyres: Goodyear Connector Ultimate, tubeless-ready, 40mm
- Seatpost: Factor Ostro Gravel (Zero + 20mm setback)
- Handlebar/stem: Black Inc HB02
- Saddle: Selle Italia SLR Boost
Factor Ostro Gravel SRAM Force XPLR + power meter
- Price: £7,570 / $8,799 / €8,720
- Frame: Factor Ostro Gravel
- Fork: Factor Ostro Wide Stance fork
- Groupset: SRAM Force eTap AXS XPLR
- Power meter: SRAM Force AXS power meter crankset
- Wheels: Black Inc Thirty-Four carbon hookless
- Tyres: Goodyear Connector Ultimate, tubeless-ready, 40mm
- Seatpost: Factor Ostro Gravel (Zero + 20mm setback)
- Handlebar/stem: Black Inc HB02
- Saddle: Selle Italia SLR Boost
Factor Ostro Gravel Frameset
- Price: £4,730 / $5,499 / €5,450
- Frame: Factor Ostro Gravel
- Fork: Factor Ostro Wide Stance fork
- Seatpost: Factor Ostro Gravel (Zero + 20mm setback)
- Handlebar/stem: Black Inc HB02
Factor Ostro Gravel Frameset + Black Inc Wheels
- Price: £6,450 / $7,499 / €7,430
- Frame: Factor Ostro Gravel
- Fork: Factor Ostro Wide Stance fork
- Wheels: DT Swiss ARC 1600 50/62mm
- Seatpost: Factor Ostro Gravel (Zero + 20mm setback)
- Handlebar/stem: Black Inc HB02
