I always wanted to have an electric bike so here i am , i'm 17 and ive got 400€-500€ that i can invest to make it but i have no idea how could someone explain wich part si need and where i can find them id like my bike to go about 60km/h (40 miles per jour )! Thanks in advance!!

Welcome to the Forums

I moved this from Introductions so that you'll get some answers to your questions.

You're 17 and want an e-bike that goes 40mph? Kid, you'll poke your eye out.

Try this thread: Endless-sphere.com ? View topic - Help choosing a kit for 36mph+

Do you already have a suitable bicycle for this build? If not, that's a very tight budget for an e-bike that's capable of handling such speeds. Btw, please don't fall for the e-bike hype you see out there. There's a lot of baloney speed claims being made by hack e-bike "builders" that really don't know what they're doing.