Gravel exotics: Speed gravel bikes - the most important info & 6 models at a glance
Timo Dillenberger
· 16.05.2024
In this article, we use so-called affiliate links. With every purchase through these links, we receive a commission from the merchant. All relevant referral links are marked with . Learn more.
Whoever came up with the term aero gravel bike didn't do the bike category any favours in terms of image! Many off-road enthusiasts turn up their noses at the term. Aerodynamics and relaxed biking through fields and meadows have little in common. Even if you really accelerate, this pleasure takes place in the amateur sector at speeds averaging around 22 or 23 km/h, a range in which aerodynamics play little or no role. For wing-shaped frame and handlebar profiles to be worthwhile in this respect, you would have to keep the needle consistently above 30 or even 32 kilometres per hour. Gravel world champion Matej Mohorič and his professional colleagues can and do do this, even though his Merida bike does not have such extreme shapes as some of its competitors.
It is or would be much more appropriate to use terms such as race or speed gravel bikes for this relatively new type of model that is as light and sporty as possible and designed for shorter distances. The aero shapes of the frame or handlebars are more like the icing on the cake, as is the complete integration, i.e. internal routing, of all cables and wires. If you look at the models on the market or our selection here, you will often recognise direct similarities to the road racing bikes of the corresponding brand. Sometimes they even share components such as the fusion of stem and handlebars known as the cockpit - stylish and streamlined, but it is just as difficult to change the seating position afterwards as it is to attach additional equipment, such as a light or bag, to the strongly ovalised handlebars.
What makes speed gravel bikes so special?
As mentioned at the beginning, speed gravel bikes lie between road racing bikes and cyclocross bikes in terms of their area of use. High speeds and a steady pace meet firm to loose and sometimes rough surfaces. Highly technical passages with jumps and carrying elements as in cyclocross are not necessarily part of it, nor are completely unpaved paths and downhills as in MTB. In order to be equipped for such routes and the slowly increasing number of gravel races, the framesets have had to slim down and stretch themselves. There are no defined limits, but speed gravel bikes should weigh less than nine kilos.
Almost more important: the geometry must allow a more forward leaning position than on an all-rounder, flat seat tube angles or stems under 90 mm are taboo, as is the stack/reach ratio of around 1.5 or more. This means that the top tube of speed gravel bikes is longer in relation to the frame height and you sit more directly above the bottom bracket. This creates more efficient biomechanics for pedalling as well as weight distribution further on the front wheel for more grip and more agile handling.
Of course, the more streamlined riding position is also a fundamental part of the "Aero" Gravel. Disadvantage: The seating comfort suffers and the bike is less keen to go straight ahead. This would be wrong for relaxed and, above all, longer tours. Many newcomers find the agile handling to be intimidating, especially on uneven surfaces. And because they are not suitable as touring bikes or commuters anyway, there is usually no need for threaded eyelets for attaching luggage or cable ducts for lights.
In principle, speed gravel bikes take you back to where the Americans once wanted to go with the forefathers of gravel bikes: They are actually racing bikes that perform well even on poor roads and paths thanks to greater tyre clearance and a somewhat more stable design, and are significantly less prone to punctures. In addition to more grip and robustness, the thick tyres also allow less air pressure and therefore considerably better comfort than on a road bike. As TOUR recently found out in the wind tunnel, even a five to seven millimetre difference between the wide and narrow gravel tyres results in an aero saving of a few watts. This means that widths of around 40 mm are more likely to be used on racing models.
The target group for speed gravel bikes
Although their range of applications is significantly narrower than the models we have tested, for example, the Aerogravels are almost without exception among the price spearheads in the overall segment. Lightweight construction, airflow optimisation and top components have their price. That doesn't mean that you automatically buy the best bike for you with such an expensive bike. Even if the comfort values of one of these high-end gravel bikes are significantly better than their road counterparts, no focus was placed on long-distance comfort and everyday use during development.
These bikes are incredibly fast to ride if you have the appropriate technical and physical skills and if you can do without smooth running and highly predictable handling. Spending several hundred euros more for mere aerodynamics is only worthwhile for trained and competition-orientated bikers. Road cyclists who are considering a gravel bike could consider buying an Aerogravel with a second set of wheels and road tyres instead of two expensive bikes.
Info, tests & tips: Overview Gravel Special 2024
>> Gravel exotics: Damn fast - 6 race/speed gravel bikes & the most important info (just opened)
6 remarkable speed gravel bikes
Ridley Kanzo Fast
The Belgians confidently call their Kanzo Fast the fastest gravel bike in the world. At least it is the most customisable, you can put together your Ridley bike online almost bolt by bolt, the frame set starts at 2,999 euros. Its top tube is probably the longest in the off-road world, measuring 56.5 cm in size M, yet the STR value remains in the orange range because the "long" head tube raises the handlebars. With bent arms, however, you sit almost horizontally, the stem is even angled downwards! According to Ridley, the low-set rear triangle provides a bit of comfort.
- Price: 5499 Euro
- Weight: approx. 8.1 kilos
- Stack/Reach: 1,525
- Drive: Sram Rival XPLR AXS 1x12
- Brakes: Sram Rival AXS
- Variants: In addition to 13 gear combinations, hundreds of wheel, equipment and colour combinations are possible via the configurator.
Felt Breed Advanced
On the Felt Breed, the brake line does peek out from under the cockpit. Nevertheless, we wanted to present it because of its versatility. The sleek aero frame with the sinfully expensive Zipp wheels can be transformed into a comfort bike. The fork can be swapped for a suspension one without destroying the geometry, and the thick, stiff seat post can be replaced by a thinner one with a rubber sleeve. This duo allows for small springy movements. And it is the only Aerogravel that allows 50 mm tyres. "Two wheels" with eTap gears for the price is okay!
- Price: 5999 Euro
- Weight: 8.6 kilos
- Stack/Reach: 1,494
- Drive: Sram Force XPLR AXS 1x12
- Brakes: Sram Force 1, 2-piston
- Variants: 3 models from 2999 to 5999 euros with SRAM Force eTap, Shimano GRX 820 or 610 groupset, top model only in Limelight
Rose Backroad FF
The Rose Backroad FF is brand new, significantly lighter and longer than its all-round counterpart, but not quite as uncompromising in terms of riding position or sacrificing practical elements. The saddle has been moved forwards, you have a lot of power almost above the bottom bracket (top model comes with watt measurement), but the upper body angle is humane for racer bikes. We really like the specially developed gravel cockpit, which offers upright, sporty, wider and narrower handlebar positions. The cables are, of course, completely internal, and adventure gadgets such as 45 tyres and provisions bags have been retained.
- Price: 4999 Euro >> available here
- Weight: 8 kilos
- Stack/Reach: 1,409
- Drive: Sram Force XPLR AXS 1x12
- Brakes: Sram Force AXS
- Variants: 2 models with Sram Rival AXS or Force AXS, 6 heights and 2 or 3 colours, prices 3499 or 4999 euros
Bianchi Impulso RC
The traditional racing bike brand only has a small range of gravel bikes, including a racing machine like the Bianchi Impulso RC. Its head tube starts at a tiny 10 cm in size XS, and cranks with up to 52 teeth fit next to the chainstay - an extremely large amount for off-road orientated bikes. The top version RC shown here comes with 2 x 12 gears, an advantage over single-speed bikes for sporty riding. Frame profiles, 44 mm high wheels and a sporty riding position promise low air resistance, while the steep fork ensures manoeuvrability. Including image bonus not super expensive.
- Price: 6849 Euro
- Weight: 8.1 kg
- Stack/Reach: 1,417
- Drive: Sram Force AXS 2x12
- Brakes: Sram Force AXS
- Variants: 3 versions with Sram Force, Shimano GRX 820 or 610 for 2999 to 6849 euros, 2 colours
Pinarello Grevil F9
It is called the "Offroad Dogma" on the website ("Dogma" is the name of the professional racing bike from the Italians). You can see with the naked eye that virtually everything on the frame has been done for the wind tunnel; even the fork blades are positioned in the wind so that they direct the flow around the down tube and any bottles - perhaps slightly exaggerated for gravel speed. More practical: the variable wheelbase; the bike can be made more manoeuvrable or more stoic by means of a reversible inlay in the rear axle mounts. With a painted seat post it's deadly chic, but expensive.
- Price: 8499 Euro
- Weight: 8.8 kilos
- Stack/Reach: 1,545
- Drive: Shimano GRX Di2 1x12
- Brakes: Shimano RGX 820
- Variants: 8 models in 6 heights with Shimano GRX (mech. & Di2), SRAM Rival eTap or Campa Ekar, prices: 8,499-4,199 euros, 6 colours
Merida Silex 10 K
Mohorič could have travelled the world on the Merida Silex 10 K. The civilian version of the world championship bike combines details from racing and travelling. The slim carbon frameset and the Reynolds carbon wheels reduce the weight and improve agility and airflow. Despite the high-end carbon fibre, fixed points for luggage and a long-distance, almost MTB-like geometry have been used. An electrically lowerable seat post is fitted ex works, which is great on difficult trails, as is the X01 rear derailleur, also borrowed from the MTB, which keeps the chain tighter. A lot of bike for a lot of money.
- Price: approx. 8999 Euro
- Weight: 8.77 kilos
- Stack/Reach: 1,473
- Drive: Sram X01 Eagle AXS 1x12
- Brakes: Sram Red AXS
- Variants: 3 WM bike variants from 2349 euros, Shimano GRX-Mix or 820 groupset, Sram Red & AXS Eagle combo with power meter, 1-2 colours
Speed gravel bikes in detail
Wireless
The test bikes at the front of this magazine all show solutions for routing cables and hoses relatively cleanly into the frame. Aerobikes take this integration to the extreme. Cables and hoses run from the handlebars directly into the cockpit and from there through the frame and fork to their "place of use". Cables that are not exposed to the wind save a similar amount of power as aero frames, approx. 10-14%.
Pointless?
We have already questioned the usefulness of the wide flared lower links. They make sense on aero racers, not because the bars are wider at the bottom, but because they are narrower at the top. Road riders today use much narrower handlebars to make themselves smaller against the wind. That wouldn't give you enough control for gravel riding. Very narrow handlebars at the top and "normal" width at the bottom are the compromise.
Uncompromising
The sacrifice of comfort in favour of maximum power transmission and dynamics goes right down to the last detail. In addition to the frame and wheels, handlebars, stems and seat posts are generally much stiffer than on all-rounders. On the Ridley Kanzo the support is even clearly ovalised, which improves the airflow, but stiffens in exactly the direction in which flexibility would ensure seating comfort.
Restless
In size M, the Ridley Kanzo has a short wheelbase of 1026 mm, mainly due to the short chainstays (photo: the HR protrudes far into the frame) and the steep head angle of 71.5 degrees. Such geometries turn speed gravel bikes into slalom machines, but they have to be mastered. Especially because the top tube is as long as on a road bike and therefore front-heavy.
Non-resistant
The rims on Matej Mohorič's bike (Merida Silex) are 60 mm high, made of carbon, have 24 blade spokes and a retail price of 2200 euros. This lightweight construction naturally suffers more on gravel than 32-hole aluminium wheels. 40 mm "narrow" tyres also provide only limited protection and their suspension comfort is also limited. But: The estate rolls fast, and on the Speedgravel you just accept such compromises.
