Nat Bromhead
We get fast and furious with ‘the gravel race bike of the moment’, the Ostro Gravel from Factor.
Of the four winds, a southerly change is typically the least welcome. And not just by cyclists, but sailors and no doubt many other outdoors types as well. Southerlies can be strong, can often carry rain, usually hit hard, and deliver sudden and noticeable change.
Southerlies tend to stand out from the pack, so far as the weather goes, being the antithesis of a warm and welcome northerly, a refreshing easterly or sea-calming westerly. Southerlies are bold, brash and forthright … they have purpose and mean business.
Much like the Ostro from bike company Factor, a model indeed named after southerly winds. “Ostro is the traditional name of a southerly wind in the Mediterranean, especially the Adriatic. Its name is derived from the Latin name ‘Auster’, which also meant southerly and is part of the etymology of Australia.”
Well, there you go.
Bold, lively, spirited and strong, and much like its aero road oriented sibling, the Ostro Gravel we are reviewing here is a no-nonsense machine. From the moment the Factor box was ripped open, and we took that first glimpse of the partially assembled bike, it was clearly obvious this is a purpose-built bike that means serious business.
Fully assembled and finished off by Michael at local bike shop Cycle Spot in Mona Vale, the bike was raring to go and almost screaming “take me somewhere special”. Clearly impressed with such a thoroughbred gravel race bike, Michael agreed Factor had stopped at nothing with the design, build and delivery of their premium gravel offering.
The bike features a 900g aero optimised frame and a ‘wide stance’ fork for gravel tyres of up to 45mm. The weight of the fork is stated at 450g, however, this is the uncut weight, and it was the longest uncut fork we’ve ever seen. There’s Black Inc’s full carbon integrated bar and stem, a stealthy looking flared cockpit that provides exemplary handling and control, and looks like something out of a stealth fighter.
The bottom of the bars are 3cm wider than the tops. A serious top-shelf offering, Factor seem to have thought of everything with the delivery of the full bike. In the packaging, there was an integrated GPS / computer mount that attaches under the bars with 2 x hex screws. A second mount, this one suitable for a GoPro action camera, is also included.
Wheel-wise, Black Inc 34mm carbon gravel hoops are standard equipment, these have a 25mm internal width to allow bigger tyres to have a fuller and ultimately more aero and efficient shape. Oh, and these wheels also feature top-of-class Ceramic Speed hubs and bearings for maximum efficiency and minimal energy loss.
Talking Ceramic Speed, they also provide the headset bearings, and the bottom bracket which is the T47 standard threaded for better security and easier maintenance. Also on the BB, the outside alloy cups are anodised blue – these stand out from the frame, ooze class and quality, and look great.
To the seat post, and true to the bike’s roots and race objectives, it’s D-shaped and seamlessly integrated into the seat tube. Seat tube security – or preventing the dreaded mid-ride slippage – can be an issue with gravel bikes and this is something Factor seem to have taken into account.
The seat tube tensioner/locking plate is a lot bigger than we’ve seen on other bikes – there was absolutely no slip during our testing and it’s great to see this very annoying issue has been addressed.
The bike was supplied with a high-end Selle Italia SLR lightweight saddle. This, and the generous perineal cutout, proved exceptionally comfortable during the review and is a very impressive saddle.
Finally, the bike is delivered with 40mm Goodyear Connector gravel tyres. These are definitely not one of the more common or popular gravel tyre choices, and initial thoughts were to swap them out to tried and tested Schwalbe’s, Challenges, or Panaracers. We tested the bike on a mix of several of those tyres and can report the Goodyear’s rated highly – the gravel tyre space is hotly contested these days!
To the ride, and a bike with the pedigree and design intentions of the Ostro needs to be ridden on some serious gravel. One of modern Australia’s first regional roads was the dream destination. Heading north on the convict-built Great Northern Road near Wisemans Ferry, the bike felt at home on the hard-packed dirt and smooth gravel.
The frame is phenomenally stiff and power transfer is very direct, push on the pedals and the bike immediately responds. That said, the ride can be surprisingly smooth and forgiving providing you get the tyre pressures right and find the perfect balance between rider weight and the terrain you are tackling. The 40mm Goodyear’s have a lot to do with shock absorption and smoothing out the bumps – work out optimum pressure on each given ride and you’ll have an absolute blast.
An Out-And-Out Race Bike
But make no mistake, this is an out-and-out race bike with performance the key priority. It’s a frame that feels very well thought out and a geometry and carbon layup that’s received an enormous amount of research and development.
Factor say the frame and component prototypes were subject to aerospace engineering, extensive computational fluid dynamics and wind tunnel testing. Having ridden and spent time with all manner of gravel bikes over the past four or five years, the Ostro certainly stands out as ‘peak Gravel race’.
The bike comes standard with SRAM Red eTap AXS XPLR – with a 44T chainring, power meter, and 10-44T cassette. This felt well suited. It offered 440 per cent of range with perfect gaps between gears, silky smooth changes, and full use of the ratios. The gearing suited surprisingly well on the road as well – invest in a second set of wheels with say 32 or 34, of rubber, and you’ve also got yourself a very capable all-road machine.
Back to the ride, and the Ostro teases, tantalises and encourages the rider to push harder. Returning south along Great Northern Road, enjoying a gentle descent, slight tailwind, and a smooth lane of gravel, the bike was humming along beautifully.
To cut a long and painful story short, I crashed it heavily and the Ostro cartwheeled several times across the rough surface. The bike copped a considerable beating but seemed to take the abuse in its stride. It all checked out OK, and was ready for more.
In retrospect, the fast riding, that memorable crash, and the past few months of hardcore use have absolutely proven the Ostro’s mettle. Just like a strong southerly change, the Ostro Gravel is shipped with clout and gravitas. It has purpose, authority and is uncompromising. It’s little wonder the Ostro Grave is widely considered the cutting-edge gravel bike of the moment. 
Want one? We’d suggest visiting The Factor Website to find out more
