It is easy to fit, it took me about 2 hours and most of that time was reading the instructions and finding the tools. The hardest thing was turning the battery on. There is a very small toggle switch at the rear of the battery pack. I tried to turn it on by pressing of the fabric battery cover where marked but in the end unzipped the battery cover to view the switch clearly. The assistance is great as soon as you start to pedal the motor cuts in and off you go. Hills are a breeze, I'm a fat, 100 kg, unfit pensioner, I just sailed up them. When you stop peddling the motor cuts out and you freewheel as normal. My bike is a Skoda Fun Ride cross and when I picked the bike up to put it away I noticed that it is much heavier. I have an old 531 10 speed bike on 1" wheels and i think it would not be so suited to the conversion. I use a u lock but I need to get a padlock and chain so that I can lock the front wheel and motor up when I leave the bike. I think that if you programme the battery pack with a smaller sized wheel you can increase the top speed above the 15 mph. The motor wheel is a fair match to the existing rear wheel apart from the hub motor and spokes being black. The rear wheel has silver spokes and hub. The black rim is identical. The front wheel is laced 2 cross rather than the existing 3 cross rear. I don't know what the range is but if I run out of charge I'll just use it as a normal bike. You don't need to change gears I keep it in a fair high gear and it seems fine. I ordered it months ago and was begining to think I had been the subject of a scam when the huge box arrived. I'm well pleased with bike it rides easy and I use it for local trips.