Gravel e-bikes are a new hot trend: we illustrate their features and performances, giving you some tips to help you choose your new adventure companion.
Rather light and versatile, gravel eBikes are on a hot streak
For decades, it was the age of road bikes and some city bikes. Then came the age of mountain bikes in the 80s and 90s, and e-mountain bikes starting from 2010, when lighter lithium ion batteries arrived. As more people began using bikes and electric bikes both for commuting to work and leisure, especially with ebikes, mountain bikes feet too slow for commuting, whereas city and road bikes are instable and fragile on trails and even owned or dirt roads. Now is the moment of gravel and gravel e-bikes, combining the best of the two words: fast on asphalt, swift and stable on dirt roads and easy trails.
Three ranges of gravel: racing, versatile, and adventurous
One can easily identify three categories of gravel bikes and eBikes.
Racing gravel bikes
This category doesn’t include electric bikes. Things became serious in 2022 when the UCI, the Cyclist International Union, organized as many as 12 gravel races and a world championship.
Versatile gravel ebikes
Riding an eBike is ideal for daily commuting to work and weekly shopping tours. Nevertheless, the temptation is strong to venture off road, especially profiting from the comfort and power of electric assistance. Here the versatility of gravel bikes is an unbeatable advantage.
Adventurous gravel e-bikes
But there are those who elevate their gravel electric bike to a travel and adventure companion: bikepackers equip their bikes with bags, lights and accessories and cycle for days and weeks at a time.
What’s a gravel e-bike and what is it for
At first glance, a gravel bike may look like a racing bike designed for off-road riding, but the reality is different. In fact, this type of bike provides for a more upright and less aerodynamic posture of the rider, favouring stability and comfort in the saddle. The purpose of a gravel bike is to cover several kilometres a day, alternating between asphalt stretches, dirt roads, and undemanding trails. In order to achieve this, the designers have designed a frame with more relaxed geometries, a longer rear triangle, and a seat post with a more open angle, decisions that have increased stability and comfort, also improving grip on gravel and dusty or non-asphalt roads. The wheelbase is wider, thereby increasing the footprint and rendering the bike steadier.
Gravel bikes are bicycles with a racing footprint but designed to tackle dirt roads, paths and gravel tracks, places hitherto only accessible to mountain bikes.
The big problem with pedalling on dirt and gravel roads is the lack of stability and grip due to gravel and uneven road surfaces, which create a sort of ‘bounce’ effect that fatigues the rider and worsens progression. That’s why the seat tube of a gravel bicycle is less vertical, allowing the rider to be more upright on the saddle but also having a damping effect on vibrations. In fact, the more upright the seat tube is, i.e. vertical, the more impacts with the ground tend to be discharged directly onto the saddle and the cyclist’s pelvis. The tyres are wider, with sections ranging from 28mm to 36-38mm as a rule, with peaks of 40mm or even 55mm in some models. The problem of accommodating these larger-section tyres has forced designers to create ad hoc rear stays.
To sum up, then, we can say that gravel bikes, despite a ‘physicality’ that closely resembles racing bikes, are designed for endurance, for long journeys and to offer comfort and stability, so that you can pedal for many hours at a time without tiring your body too much. In reality, gravel bikes are also increasingly taking on a competitive imprint, with the emergence of numerous competitive events, even among professionals.
Essential elements of gravel electric and regular bikes
Materials:
Carbon fibre: The ‘racing’ material par excellence. Light, rigid and high-performance. Leaving aside the economic question, the carbon fibre frame has the advantage of vibration absorption and structural rigidity, as well as considerable lightness. The advice is to choose this material if you want to use the bike as an alternative to a racing bike for long distance rides or races, or if you want to engage in gravel racing.
Aluminium frames are usually offered as a cheaper alternative to carbon fibre frames. The advantage of aluminium, in addition to the cost savings, lies in the lightness of the structure and the strength of the TIG welds. Structural rigidity is lower than with other materials, as is vibration damping, which makes the frame less comfortable than its counterparts in other materials. Aluminium may be the right choice to create a high-end bike while keeping the overall cost down.
Steel: the merits of this material translate into structural rigidity accompanied by high vibration damping. Steel frames are the right solution if you want to make a solid bike that can support the weight of duffel bags and is comfortable, especially if you will be using the gravel bike for touring.
Titanium is virtually immune to atmospheric corrosion and ageing. Demanding cyclists, who want a bike with a reliable frame that never leaves them stranded but is as light and snappy as a steel frame, should turn their eyes to this material, although it is expensive.
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- Scott Aspect Eride – road eBike
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- Ktm Macina Gravelator Sx Prime gravel eBike
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- Scott Solace Gravel Eride 20
Geometry
A gravel bike has a profile that at first glance may lookidentical to that of a road bike, but in reality things are slightly different. The most important aspects to take into account (apart from choosing the right size) are the angles of the seat tube and head tube, which are narrower than on a racing bike. When talking about the angles of a frame one must always refer to the ground, which is the reference plan of a bicycle. The more open the angles are, the more vertical the head tube and steering tube will be, giving the bike ‘racing’ characteristics.
More closed angles correspond to more inclined tubes, which are reflected in more comfortable seats and better absorption of vibrations (longer tubes flex more and absorb impacts better). For a gravel bike, frame angles travel between 72°-75° for the column and 70°-72° for the steering, offering a less aggressive seat and a longer wheelbase, which translates into greater stability on uneven ground. Another aspect to be taken into account is the clearance between the front and rear chainstays. Since the rear chainstay of a gravel bike is farther from the front chainstays than that of a racing bike (due to the longer wheelbase, or distance between the wheels). It must be possible to mount cyclocross tyres (hence 700×33 – 700×35), but also to dare more, by installing covers that reach a higher level of stability, such as the 700×40, depending on one’s usage needs. This construction technique results in greater flexion of the chainstays and better absorption of unevenness on the ground, although the bike is less responsive (but the purpose of gravel bikes is not the maximum expression of power). The curvature of the chainstays is also important, as a wide final curvature before the connection to the dropouts provides greater absorption and flexion, increasing overall comfort in the saddle.
Transmission
Some manufacturers are starting to propose groupsets intended exclusively for gravel use (such as the GRX proposed by Shimano or the EKAR 13-speed, presented by Campagnolo), but in general the proposals are broadening, offering technical choices that range from purely ‘racing’ groupsets to the most extreme ones derived from MTBs.
Other components
Regarding shifting, brakes, motor, battery, etc., one may choose according to his needs, gravel bikes and ebikes presenting no specific demands compared to other kinds of bicycles.
