Your English is very good. Better than my French!

Since the motor is actually bigger than the legal limit, I would assume that it is capable of moving you quite well. The questions that need answered are "How quickly will it accelerate?" and "How fast will it go?"

Let's see how my high school physics skills are holding up. The motor can make 7.46Nm of torque. This torque is multiplied by the radius of the largest cog (28 tooth) on the wheel. That radius should be about 0.061 meters. (7.46Nm)(1.061)=7.915Nm Someone please tell me if I am doing the math wrong here. I don't think we even did any problems like this one when I took this class

Now, to determine the force that is actually being transmitted to the ground, the torque is divided by the radius of the wheel. I am assuming that you are using a road bike wheel which has a radius of about 0.343 meters. I may be off a tad here because I am converting from a wheel with 27 inch diameter. Forgive me, I am an American

... 7.915Nm/0.343m=23.08N. The formula for acceleration is acceleration=Force/mass. Your bicycle should accelerate at a rate of .2815m/(s^2) if the combined mass of you, your bike and the bike's batteries are 82kg.

To calculate top speed you will need to know the bicycle's aerodynamic drag coefficient. Actually this calculation really needs calculus to be very accurate. The acceleration calculation should be done with calculus as well because the motor will not always produce the same torque, and because drag will increase with speed, but we are probably close enough.