Good evening I have a really basic question if someone would be kind to answer. Let's say the push bike is not invented yet. Its a novel & great idea obviously. When approaching the patent process does it have to be drawn in details describing every single moving part and bolt or chains, brakes etc or only as rough idea, yet which perfectly explain & demonstrate the functioning. 

Let's say the patent was granted to me for push bike but there is now electric bikes coming up on scene. Are those electric bikes covered under my patent protection as they technically still bikes just modified ones & much better ones. 

You got the idea of my dilemma please elaborate. 

Thank you.