We wanted kits that would provide good performance and range, but not weigh too much. We required hill climbing ability and needed to go 20-30 miles on a charge, plus pull a bike trailer with our dog in it sometimes. This called for a strong motor and good amount of energy storage at a fairly high voltage. The kits would not be cheap, but you get what you pay for. We selected rear wheel geared motors for their slow speed climbing ability. The kits came from HTB e bikes, but had Amped Bikes on the shipping boxes. The rear geared motors are reported to provide continuous torque under low speed, uphill grinds. Ours kits came with 22 amp (continuous) controllers and 36V batteries which could produce 792 watts of working power. The kits had pretty much everything needed for the conversion except enough shims for the rear wheel so we added our own.We decided to convert each of our 20 year old bikes to a DIY electric bike. Both were garage sale specials (a Giant and a Schwinn) which we had been riding regularly for 5 years. They were in need of paint, cables, bearing and cone cleaning and reset, tires, and general tune up anyway. So I stripped off all the old parts and repainted as the first step. I was going to replace my front fork with a new one with V brakes but couldn't find any used that were long enough so switched to converting the Diamondback Sorrento I had just bought which has great brakes and a speedo. The motor-wheel combination was wider by an inch or so than the original freewheel setup. The frames had to be pulled out to widen them, but I also had to create shims so that the chain and frame wouldn't rub. I ended up with 2 standard washers on one side, and 3 custom created washers on the other (that was some work). Thinking ahead, I would have put the switches on the Giant handlebars before putting the brake levers and gear changers back on. Anyway, my wife gave permission for me to move her gears to the center to accommodate the Wuxing thumb-operated throttles. She says the throttle feels just like her gear shift. One of the requirements for Li-Ion battery packs is to protect them from shock. Unlike good old lead acid batteries, Li-Ion packs do not do well if poked, prodded or banged! Since these packs cost around $400 each, you will want to insulate and protect your investment. After much searching and trying a plastic box first, I found a set of aluminum cash boxes that could be locked and were a good fit for the battery, controllers and wires. I set up the wiring (the easy part), then bolted the boxes onto our bicycle racks, cut holes for incoming wires, then added foam padding inside the boxes to pad the battery etc. The e-bikes have been a blast to ride with more range than we thought - not sure yet about the limits since we are still breaking the batteries in! You can still get a really good workout pedaling too - and using your legs instead of battery power also extends the range... This is way cheaper than buying a new car - no insurance or registration required. Also, people don't even realize that these are electric even when you do a sudden zoom!