We have two bicycles with motors on them from Currie, the motor is in the center of the front wheel. It is virtually silent, We can get up to 28 mph on flat ground with no wind. If this bike setup is NOT WITH A RUBBER PIECE TURNING THE TIRE BY FRICTION, I would suggest buying two, one for her and one for him, and two sets of batteries each, HOWEVER, YOU deck the halls THE KIND THAT RUNS ON FRICTION AGAINST YOUR TIRE. YOU'LL BE REPLACING TIRES WAY TOO OFTEN! Remember, the more battery, the further you'll go without having to recharge. Check out the cost of 12 volt batteries that run 3 together for a total of 36 volts on each side. That would be a sweet ride for quite a few hours, and even longer if you pedal along the way. Go 30 miles, and don't worry if you're tired, use the battery power to rest when you need to. Use the battery power and pedal power when climbing hills.