What they are, how they work, what they're for and how much they cost — e-bikes, the pedal-assist bicycles. A horizon of sustainable mobility and fun, they are suitable for everyone. They offer all the advantages of a traditional bike, but with less effort.
When in the 16th century Nicolaus Copernicus argued that the Sun, rather than the Earth, lay at the centre of the planets' orbits, the world experienced a genuine overturning of the conceptual systems that had until then been commonly accepted. A "Copernican revolution" capable of changing the perception of reality. Today, an equally radical evolution is under way and promises to profoundly transform the mobility of the future. E-bikes are among us. If, until now, for the majority of people the car represented "the Earth", the pedal-assist bicycle will be "the Sun" of tomorrow. Copernicus docet.
Read also: Perché la bicicletta a pedalata assistita è il mezzo del futuro
E-bikes, or pedal-assist bicycles — also known as pedelecs (pedal electric bikes) — are hybrid pedal vehicles powered by both muscular effort and the thrust of an electric motor. The additional propulsion kicks in while pedalling, since if it could be activated without any physical input from the rider, we would instead be dealing with a battery-powered moped. The extra boost helps reduce effort and smooth out forward progress regardless of the terrain. The undisputed star of the most recent industry trade fairs, the e-bike combines transport efficiency, environmental sustainability and physical wellbeing. It is the urban vehicle of the future, as well as a leisure option accessible to everyone.
The purposes of the pedal-assist bicycle are many. One goal, however, is shared by all e-bikes, regardless of their intended use: reducing effort. A result that can benefit both those who commute by bike and those who see cycling as a means of tourism or, more generally, of leisure. Electric assistance makes it possible to cover more kilometres and reach places that would otherwise be difficult to access, especially when they involve very demanding climbs. Getting out into nature has never been so easy and enjoyable.
The e-bike is the bicycle for everyone. Older people, young people, the fit and the first-timers — everyone can find in the pedal-assist bicycle an ideal means of transport and leisure. Ranging from city models to mountain bikes, from touring variants to cargo bikes, from folding frames to ultra-light carbon ones, the market offers an endless range of pedelecs capable of meeting the most varied needs and ambitions. Those who have little time to train, or who suffer from conditions incompatible with intense physical exertion, are no longer forced to give up the pleasure of a journey or a simple zero-emission trip. Electric assistance is also used successfully in hand bikes, helping people with disabilities to share in sporting activity, and in rehabilitation programmes following injuries — not to mention tour operators who are increasingly including the rental of pedal-assist models in their recreational offerings.
Say goodbye to effort — or at least to most of it — and open the doors to fun. Whether you're riding an electric enduro mountain bike, suited to highly demanding off-road trails, or a laid-back city bike, or indeed a model designed for covering long distances, the lowest common denominator of the experience will be relaxation. All thanks to the combination of a frame — once traditional, now purpose-built — with the pedal-assist system. This technology consists of a motor, battery, computer, control unit and sensors.
In the case of Bosch systems, currently the most widespread, the zero-emission motor incorporates both the bottom bracket and the crankset (the assembly made up of the chainrings and cranks): this makes it possible to use a smaller chainring than the standard, thanks to a gear ratio that allows it to rotate 2.5 times faster than the crank. The sensors on the crankset axle "read" both the cadence and the power of the pedalling and, with a thousand readings per second, transmit the data to a dedicated control unit. This causes the motor, taking into account the selected assistance programme, to deliver a specific amount of torque — that is, thrust — which is added to that generated by the rider. The force then passes from the chainring to the chain and the sprocket cassette, just as on a traditional bike.
A motor weighs around 4 kg — not negligible. And on top of this additional weight must be added the rechargeable battery, usually lithium-based with a capacity measurable in Wh (watt-hours), and the system management unit that allows the rider to choose from different power delivery modes. These programmes alternately favour traction, charge conservation or maximum assistance, while simultaneously detecting gear changes and reducing assistance to prevent damage to the drivetrain. As for charging, a standard domestic socket is sufficient to restore the cells' energy in a few hours, while the gearing is similar to that used on traditional models. Technological research is, however, bringing hi-tech solutions to the fore, such as Rohloff systems (14-speed) integrated into the hub, capable of changing gear even from a standstill, and the NuVinci continuously variable system, characterised by automatic management and an infinite number of speeds.
The positioning of the motor on an e-bike follows four standard strategies: in the hub of the front or rear wheel — a solution that, it must be said, does not aid rideability — at the bottom bracket, to the great benefit of lowering the centre of gravity and achieving an even distribution of mass between the axles, near the tyres, known as "roller" propulsion (now very rare), or "embedded" within the frame tubes, transmitting motion to the bottom bracket via a gear system. More advanced configurations feature an internal freewheel that allows pedalling without engaging the motor, unless the rider opts for a riding programme that includes energy recovery during braking, thus applying a moderate deceleration effect.
From a legislative standpoint, the e-bike enjoys the same advantages as a traditional bicycle: it can freely access cycle paths and limited traffic zones, requires neither insurance nor a number plate, does not require a licence, and a helmet is optional. Common sense, however, suggests always protecting one's head. These advantages are guaranteed provided the e-bike complies with article 50 of the Highway Code, which establishes that the motor must not exceed 250 watts of power and that the assistance must be conditional on pedalling. In addition, the electric assistance must deactivate once a maximum speed of 25 km/h is exceeded. If this does not happen, as mentioned at the outset, what we have is a zero-emission moped, and therefore subject to registration, a number plate, and compulsory licence and helmet.
The main drawback of the pedal-assist bicycle? For now, the only downside is the price, which is inevitably higher than a "muscle-powered" bike. The cost, naturally, varies depending on the model, frame material, weight, intended use and components. Setting aside conversion kits for the moment — which allow a traditional bike to be transformed into an e-bike — pedelecs built as such from the outset start at around 500 euros on the price list. For that sum you get an entry-level city e-bike with modest performance, a (lead) battery with a useful life of just a few years, and a range that rarely exceeds 30 kilometres. To get hold of a bike with good performance you need to spend at least 1,500 euros, which buys you advanced software capable of detecting the characteristics of your pedalling and the terrain, instantly adjusting the electric assistance. With no budget constraints, it is possible to go up to 15,000 euros for the most extreme and specialist mountain bikes.
