You might want to check out my thread on the OneMotor system. for road bikes or light bikes, it's a no brainer imo. max weight for the biggest battery system is 6.5lbs inclusive, so you're not turning your nice riding bike into an anchor. Speeds can be locked at 20mph or up to 28mph depending on region. PAS with 9 levels. But the best part is it comes off in 5 seconds (really) leaving nothing on the bike at all, no battery, no motor, no controllers. So no theft worries. And - unlike a hub system - when you pause the PAS the motor fully retracts from the wheel so there is no cogging or drag. I absolutely love mine. Happy to answer questions if you have them; totally understand if it's not right for you, too. Oh - and you can move it to any other bike if you get a new one in the future, too.