Look at some photos of installs before buying a motor - you lose some ground clearance vs a built in motor. I looked at diy a bit as well, and it just seemed easier/better to buy something vs trying to retrofit an older bike. And, with a new bike, you get the bigger tires, disc brakes, integrated battery, etc. The M2S I have is basically the Bakcou mule, only less money. I am not a small person, and it just climbs hills like nothing. Battery life with the bigger bikes/motors isn't as good though.