In Europe there are three different classes of e-bikes, each with its own speed limit: 

Class 1 E-Bikes: These are pedal-assist bicycles that only provide assistance when the rider pedals. The engine switches off as soon as the driver reaches a speed of 25 km/h.

Class 2 E-Bikes: These are throttle-assist bikes that provide power without the need to pedal. The engine switches off as soon as the driver reaches a speed of 25 km/h.

Class 3 E-Bikes: These are pedal-assist bicycles that only provide assistance when the rider pedals. The engine switches off as soon as the driver reaches a speed of 45 km/h. Class 3 e-bikes must have a speedometer so that the rider can monitor their speed.

It is important to note that these are the standards for Europe and different regions may have different regulations regarding e-bike speed limits. It is recommended that you check the laws and regulations in your area before riding an e-bike.