BIKE REVIEW – Factor Ostro Gravel Bike

Main Features of the OSTRO Gravel

Weight : 913g (painted 54 cm frame), 490g (uncut fork), 8.05 kg as tested below.

Key Points : Aero optimized gravel bike with a fully integrated design and the clearance ability to fit up to 45mm tyres.

The Need For Speed And The Bike That Statifies That Need

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Factor Ostro Gravel Bike – built to be fast, versatile and compliant wherever it finds itself.

The eagle eyed of you may have seen images of a Factor OSTRO on the gravel early on this year being raced by Factor sponsored athletes. You may have initially thought, are these guys crazy racing a road bike at rough gravel races like Unbound Gravel? Or, on the other hand, you may have noticed key features that hinted this was not the standard OSTRO VAM road bike but rather a completely new bike in the making. You were right!

Welcome to the Factor OSTRO Gravel!

2022 has been a big year for Factor on the dirt. Earlier this year they launched 2 mountain bikes, a dual suspension and a hardtail, and now they have launched their latest gravel bike offering. Totally different to their current option, the Factor LS, and one that will possibly be the beginning of a new trend in the way gravel bikes may be heading.

A few years ago, Graham Shrive, Factor’s engineering director, squashed the idea of needing an aero advantage on the gravel. Fast forward to 2022, where even world tour pros are turning to gravel as a career instead, and everyone has a very different stance. As with any racing, as competition increases, so do the speeds and therefore a point has been reached where aero optimized bikes, and equipment, can offer a significant advantage to its riders.

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Factor Ostro Gravel Bike – designed with modern geometry to suit every aspect of gravel racing.

Built to be fast, versatile and compliant wherever it finds itself, the OSTRO Gravel takes its mentality and key features from its road racing sibling, the OSTRO VAM. It has been designed and developed to dominate the gravel scene with its low weight, high stiffness, superior handling and incredible aero advantage. It is an “all-road star”. Whatever the terrain and whatever the situation, the OSTRO Gravel is fast and might just be the fastest too.

You would be wrong to think that you can just take an aero road bike, increase the tyre clearance, add some compliance and slap some knobbly tires on to get an aero gravel bike. It may look this way from the outside; however, road bikes are aero optimized around much higher speeds. So how did Factor turn a “road superbike” into a “gravel superbike”? Well, here it is in a nutshell.

Using modern geometry, a fully integrated Black Inc cockpit (which they already knew was fast) and their knowledge from designing the OSTRO VAM road bike, they created a robust-but-light frame that is said to be designed around the lower speeds of gravel racing. They then added clearance to house 45mm wide rubber, specced it with Black Inc THIRTY FOUR carbon wheels and an electronic groupset and they landed up with a pretty perfect package for going fast on the dirt!

And, if you swap to some skinnier road tires, it will be just as fast and as good on the tarmac. This truly is a possible quiver killer of a bike.

What’s more to mention is that the OSTRO Gravel frame comes with a limited lifetime warranty! That’s quite a way to back up your product and show that you’re confident in it.

We’ve had our hands on a demo bike for a few weeks now and can confidently say that riding this bike has been a dream. It’s light, responsive, super fast and most of all comfortable even after 5 hours in the saddle. “That was out of this world” Bernat, a sales team member, had to say when he got back from his first ride on it.

Now that we’ve had the time to digest our thoughts and feelings after riding it, let’s take a deeper dive into this new gravel “superbike”.

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Factor Ostro Gravel Bike – new gravel “superbike”

Factor Ostro Gravel Bike – The Cockpit

Looking at the front end of the OSTRO Gravel, you may think it’s a replica of the OSTRO VAM road bike. In some way you are right. The aesthetics and super clean cockpit are identical but it’s what you can’t see that is different and it’s in a very good way.

Factor have used a round steerer here as opposed to the D-shaped steerer they have previously used to allow the cables to be run down the face of the steerer. On the road bike, Factor were all about minimizing the frontal area of the bike to improve aerodynamics but at the lower speeds of gravel, this didn’t make all as much impact. This allows them to have a slightly bigger frontal area which opens doors to various, more simple methods of internal routing for the cables. A round steerer is also stiffer and more conducive to handling the terrain it will constantly find itself up against.

Sticking with durability of its components, Factor have specced the OSTRO Gravel with CeramicSpeed’s newest technology bearings in the headset. CeramicSpeed’s Solid Lubrication Technology (SLT) bearings come with a lifetime warranty meaning that you should never have to replace or maintain these as you do with normal bearings which is truly a blessing for a fully integrated bike.

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HB02 – one-piece system BLACK INC integrated bar and stem combo.

For the handlebars, Factor have used their own BLACK INC integrated bar and stem combo but this isn’t the same bar and stem system you’re used to seeing on the road bikes. This is a wholly new designed one-piece system, named the HB02, that is said to save 5 – 6 watts at 48kph over the previous bar-stem system and up to 9 watts over a standard handlebar and stem combination.

Often, on the gravel, one piece systems can either be too stiff or not stiff enough and they don’t allow for any micro adjustment in the roll of the bars. However, not once did we find any of this to be an issue with the HB02 on our test bike.

This bar is as comfortable as it is fast thanks to its well engineered ergonomics which provide more back sweep for a natural wrist angle on the tops, more wrist clearance and hand positions thanks to the chamfered corners, a drop shape that accounts for the longer reach of the latest Shimano and SRAM shifters and a 7-degree flare that starts below the shifter mounting point. The flare adds 3cm of width in the drops, a figure carefully judged to suit all applications, Factor says.

Although this seems like the perfect bar stem combo, Factor have acknowledged the fact that everyone has their own favorite position. Thus, part of the reason for going back to a standard round steerer and simpler cable routing system was to make the front end easily compatible with various third party internal routing systems and bar stem combinations, so you can always have the touch points you want.

Factor Ostro Gravel Bike – The Wheels

The OSTRO Gravel is specced with BLACK INC’s newest THIRTY FOUR gravel wheels. Like the bike itself, these wheels are dedicated to speed on gravel. Their 34mm depth maximizes their aero gains while keeping weight to a minimum and balances the fine line between stiffness and compliance. Designed with a internal width of 25mm, the THIRTY FOUR allows bigger tires to take better shape and paired with the hookless design it makes seating tubeless tires a breeze even with only a standard floor pump. Our test bike came with Good Years new Connector gravel tires which were the perfect match of grip and speed for the terrain we have around Girona

A very neat feature of the newly designed rim is the secondary shoulder which keeps the tire securely seated in the event of a rapid deflation, allowing you to come to a safe and controlled stop.

We didn’t have any blowouts to test this, thankfully, but a feature of many of our Girona routes are some technical, rocky sections. Whilst trying to get tyre pressures right we did have a few moments where we banged the rim and clinched our teeth in hope that we did no damage and not once did anything happen to the rim and nor did it lead to any pinch flats. That is a mark of a well designed rim and a brilliant piece of equipment.

Helping keep things moving fast, the Black Inc hubs house CeramicSpeed wheel bearings for ultimate efficiency and free speed.

Factor Ostro Gravel Bike – Frame Features & Geometry

As previously mentioned, the OSTRO Gravel can fit up to 700 x 45mm tyres on the front and the rear and that is with 4mm of clearance on either side Factor says. That’s plenty of room to fit rubber for just about every application. And frankly, if you want to fit much more than that to a gravel race bike then maybe you should start to think about a mountain bike…

This bike has plenty of other unique features though. It has three water bottle mounts. Two in the main triangle and one under the down tube. It also has mounts on the top tube for some extra storage for those precious snacks and maybe some spares if you’re not into using a saddle bag for that.

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The OSTRO Gravel has space for 2 water bottles in the main triangle and has mounts on the top tube for a top tube bag.

Factor have also redesigned their nifty outfront computer mount. The new aero integrated bar-stem system gains a GoPro-style computer mount, adding angle adjustment and a more supported second mount for a light or action camera.

Another cool feature of the new OSTRO Gravel is that it uses a CeramicSpeed T47 bottom bracket. If you’re not so clued up on why this is cool, well it’s because this BB standard offers a secure fit within the frame which has been proven to be one of the most maintenance free and most importantly one of the most creak free BB standards on the market. Making every ride a peaceful ride. It also allows for the use of a wide range of spindle diameters so as not to limit you to any specific type or brand of crankset if you want to change it up.

The OSTRO Gravel has been designed with modern geometry to suit every aspect of gravel racing. What does this mean? It is the perfect mix of race performance oriented geometry and comfort. Factor have chosen to go with longer reach values for each of the frame sizes, to get that racey feel, but they haven’t been too aggressive on the stack values allowing just about anyone to get the right fit for what they want without having to use a stack of spacers under the stem to raise the bar.

Factor also noted that some things don’t work for all sizes of bike. So, they have designed fork offsets particular to each size of frame to ensure that each customer has the best ride experience possible.

Factor Ostro Gravel Bike – The Build

Our test bike came straight from Factor so it is exactly the bike you are able to purchase from us in store as well as having the option of the other builds available such as the 2x SRAM Force build which retails for €7711 excluding VAT/ IVA.

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Factor Ostro Gravel Bike – SRAM’s Red 1x XPLR AXS groupset

Our Naked Grunge colorway frame came with SRAM’s Red 1x XPLR AXS groupset. This is SRAM’s top of the crop 1x gravel groupset. With the 44T front chainring and 10-44 cassette, this groupset is suited for just about every type of rider on all terrains. The jumps between the gears are tight and smooth and offer a high enough gear for those faster sections as well as an easy enough gear when things get a bit steeper. If you find yourself riding looser and steeper sections more often than not, then a simple down size on the chainring would ease things up for you.

The crankset came specced as SRAM’s power meter option from their in-house company, Quarq, which is one of the most accurate units on the market. The aforementioned, super impressive Black Inc THIRTY FOUR, wheels came with Good Year Connector 40mm tires which offered all the speed we needed and the grip to go with it for our Girona gravel routes.

A benchmark of a great bike is how “complete” a bike it is straight out of the box and Factor have nailed the build of their OSTRO Gravel options. There is nothing we would change or fault on the factory spec builds from Factor.

Factor Ostro Gravel Bike – The Ride

After the rest of our team had had their turn to test the bike, I finally got mine and after seeing their faces on returning from their test ride I couldn’t wait to give it a whirl. I luckily got to spend a few days riding it so I could really test it on multiple rides and on all types of terrain.

When I first picked up the OSTRO Gravel, I knew right away I was looking at a gravel machine. Looking at the dropped seat stays, aero shaped fork and down tube, and the integrated aero bar-stem I knew riding this bike would feel like an aero and snappy race bike. I was not disappointed.

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Factor Ostro Gravel Bike – a gravel machine.

Clipping in for the first time, I could immediately feel the engineering and craftsmanship put into the bike as a whole, complete package. The shape of the new aero handlebars was the perfect medium for someone who likes a flatter shaped bar, but doesnt like the sluggish and bulky feeling that many integrated aero bar-stem systems have. My hands were comfortable in just about every position I could imagine trying and more importantly I felt in control the entire time in all the positions, on all terrains.

The geometry was confidence inspiring. The handling was reactive and conducive to fast riding on every terrain I touched. The head angle is slack enough to take on steep descents on the dirt with confidence while still not feeling sluggish with accelerations out of the saddle when I wanted to put some power down. I was even confident enough to test the bike on some rougher trails that I wouldn’t test most drop bar bikes on but this confidence inspiring ride led me astray and, again, it did not disappoint!

The more time I spent riding the bike, the more I was able to pick up on the “comfort” engineered into the bike. There was just the right amount of compliance I would expect from a gravel race bike. Even after 5 hours of good gravel riding, I didn’t once hope the ride would end soon because I was uncomfortable. Of Course a big part of this is tyre choice and the pressures you choose to run but once this was dialed in, comfort was never a problem!

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Factor Ostro Gravel Bike – with the soul of a road racing weapon.

We would be wrong not to touch on its possibility as a “do it all bike”. Its OSTRO VAM road bike aesthetics immediately made me think this a gravel bike with the soul of a road racing weapon. I wasn’t wrong and the OSTRO Gravel proved itself as a road option too. Riding on the road, I felt confident and fast. Whether I was in the saddle or sprinting for townsigns against my friends, I could feel the power transfer through the pedals was incredibly efficient. It, also, cornered almost exactly as my road bike would and there were moments where I almost totally forgot that I was actually riding a gravel bike. Although a 2x drivetrain would make it a better ride on the road, I think it’s fair to say that I may have found my definition of a quiver killer. I didn’t have any second thoughts about joining in on a road group ride and Factor have even gone through the steps to have the OSTRO Gravel registered as a UCI legal road bike. So, you really would have no issues if you wish to have this as a one bike that does it all and go dabble in a road race or two. I certainly would.

The OSTRO Gravel is a bike built to go fast. Be it gravel, road, bike paths or anywhere in between, the eviscerating ride experience that the Factor OSTRO Gravel provides, inspires confidence and speed in each and every pedal stroke. It is a phenomenal bike that is made for those who love to ride bikes fast and, now, want to carry their need-for-speed onto the gravel as well.

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Factor Ostro Gravel Bike – made for those who love to ride bikes fast.

If this review has whet your appetite, drop us a call or send us an email and let us help get you on the bike of your dreams. Our fantastic Eat Sleep Cycle team of salespeople and mechanics are always only a phone call or email away.

If you find yourself in Girona, be sure to pop into the store and if you’re wanting to explore the abundance of phenomenal riding Girona has to offer, why not avoid the hassle of traveling with a bike and rent one from us? We have one of the largest rental bike fleets to match just about every rider’s wants and needs. Renting a bike is also a great way to test a bike you may be thinking about. All our rental bikes are what we sell in store so rent one and ride it before you buy it.

Written by Lee Comerford
I am co-founder of Eat Sleep Cycle. For 8 years we have created custom cycling experiences in Europe and beyond. We help our guests experience the very best cycling in Europe including Girona, the Pyrenees, Tuscany and the Dolomites, the French Alps, Andalucia and beyond. We specialize in customizing cycling experiences for groups, agencies and our corporate partners. We believe in empowering and motivating the local community to cycle so we also run vibrant Cycling Hubs in Girona and Málaga. Our Hubs are a place you can find all your cycling needs from bike hire to cyclist friendly food and great coffee. Through 10 years working as an engineer, operations manager and sales manager, the bike was always my escape – venturing to new places, meeting new people, seeing amazing things, suffering a bit. Now my focus is helping others to enjoy that same escape, whatever the level, age or nationality. I believe that cycling brings people together and Eat Sleep Cycle was born through this desire. Our vision is to bring down barriers through exploring the world on 2 wheels.