Electric bike kit offers both front and rear geared or direct drive motor options as well as lead acid or lithium ion batteries. These kits also offer twist grip or thumb throttles and brake lever switches that stop the electric assist.
Here is my review of the most economical electric bike kit with a 350 watt geared front hub motor and a lead acid battery. There are many other electric bike kits on the market. These are just a few that I believe will provide you a good kit for an economical price. For more ideas on kits, here is a guide to electric bike kits. Ridekickoffers a trailer that can easily and quickly add electric assist to your current bike. The trailer is also quickly removable when you don’t want or need the assist.