I am going to say straight out I know nothing about all this, But I am hell bent on converting my old gt Lts to electric. I decided that she is was great mtn bike for her day and deserves more that the $500 I was going to spend. so I have decided to go with a mid-drive 1000 watt motor the new baffling and a 48 or 52 volt battery . Now keeping in mind I am new to this I don't understand all the conversions etc. or how the controller works exactly. I have figure out it is possible to over heat some of the controls and motors so can some one explain what I need to understand interns of amps, volts and watts and how big or how high a rated c controller must be for certain motors

I do know that amps x volts = watts. but how does really work when applying it to the bike and the controller?

Why are some controllers better than others and the issue with lithium ion batteries if any? and last but not least is BAFANG the way to go what about cyclone?

So if you have say a motor rated at 3000 watts but are only using a 48 v battery and a controller of say 40 amps then you would be at 1920 watts . far less than the motor is rated.Is that right? Would this mean the motor would be sluggish ?
Does it take the full 3000 watts to make it perform well or would it be more like a safety factor to avoid burning up your motor?

Is burning up your motor more of a concern on hub motors or mid drives?

What is typically the weak link in the system motor, battery or controller?

I come from a 4 wheel drive back ground and we usually use the easiest part to replace as weak link in the system Ie it is easier to replace a u join on the drive shaft that to replace an axle in the field.

lastly I am 62 weigh like 250 and standup paddle surf so I am looking for a e bike that cannot say a 50 lb trailer and my F-- A-- and not burn up in the process
plus get me more exercise with destroying my knees, plus go off road. The road to the beach is mostly flat with some short but fairly steep hills maybe 100 - 200 feet of elevation gain at 6 % i am guesing.