My macwheel 28

[Fergie666]

I purchased a macwheel 28 for my wife 18months ago i recently brought a new battery put it on the bike but it still doesnt work the battery is 100% ok and charged but when applying the electric mode it wont go,, it will if the backend is lifted off the ground im stumped and the mrs is in bits, any ideas as to what it is could be ,could it be the display unit or motor ?????please help me lol thanks

 

[Snoop]

Welcome!

If it stops only when under load, my thought would be something with the motor (not a mechanic, though).