Ebikes: hub motor or central engine?

2016-11-23 18:18

Ebikes: hub motor or central engine?

Is it one of the most asked questions in the store? Which electric bikes are going better, those that carry motor to the wheel or those that equip central motor? Our answer is that in general the central engines are better, but there are exceptions. The wheel motor is the best option for economical urban bikes, while the central motor is practically the only possible solution for regular mountain bike riders and long-distance riders.

Both have advantages and disadvantages. Let's analyze them.

Central engine

Bosch, Yamaha and Brose, to mention the most recognized manufacturers, have in their catalog motorizations that we could call intelligent. Equip pair sensor, so we have more power depending on the force we exert on the pedals.

The advantages of the torque sensor are numerous:

-Compared to the engines to the wheel, they convey a feeling very similar to that of riding with a conventional bicycle. The more you squeeze, the more you run.

-The battery lasts longer. Equal amperes between a bike equipped with torque sensor and one that does not carry, the first can make many more kilometers with a single charge. While the second usually waste amps with unnecessary accelerations.

-Reaction immediately. If you have torque sensor, just make some force on the pedals so that the bike starts moving. If you do not have it, you should make at least half a turn of pedals before the motor activates.

-Conduction Much more accurate in mountain. In sensitive situations such as a trial bike, on a bicycle with a wheel motor you should always have your fingers close to the brake levers to prevent an unwanted acceleration to take us to the edge of the abyss. With torque sensor the engine stop when you stop pedaling is automatic.

Anyway, be careful. There are also bikes with wheel motor that mount torque sensor, as all models of the Evo range of BH or the Catalan brand Uualk.

Other advantages of the central engine

-Easy to remove the wheels in case of a puncture

-Center of gravity low and centered

-Behind the top models there are prestigious brands such as Bosch, Yamaha or Brose, one of the world's leading manufacturers of electric components for the automotive industry.

-It supports integrated gear change

And what are the drawbacks? That there are also

-Great transmission wear. The central motor pulls the chain, which has to withstand extra stresses. As a result, pinions, plates and chain last less than on a conventional bike.

-To protect the transmission, the central engines carry a kind of clutch that greatly reduces the assistance at the time of changing the pinion. This loss of power may cause the cyclist to remain half-nailed when changing speeds on a climb.

-More expensive

-Overall they weigh more than wheel motors

-More complexity


Hub motor

The myth that the engines to the wheel do not go well is false. What has happened is that the irruption of the more technologically advanced central engines is cornering the only option that until a few years ago existed. But the truth is that the engines to the wheel work great, as long as you accept their limitations.


-Price. A wheel radiated with the engine can leave for 140 €, the same that will charge you for many of the components that equip a central engine.



-Without having a "clutch", you can change your speed in full rise without any loss of power.

-Possibility of mounting the engine on the front wheel (solution required in bikes with integrated change).


-Without having a torque sensor, most bikes with engine to the wheel only have the levels of assistance that you can select from the display. The bicycle will always look for the programmed speed for each of the three, four or five levels of assistance you have. So, for example, you can find yourself circling a pedestrian street and there is no way to circulate less than ten kilometers per hour (unless you stop the engine, of course).

-More battery consumption

-In almost all cases, they are less powerful

-Charge more weight on the rear wheel

Difficulty in repairing a puncture

-Charge more spokes

In short, the central engines are getting stronger, and more so they will even as prices fall and new manufacturers appear. But the engines to the wheel, that also stop evolving, will still have its market for many years.