How old should they be ? Is it easy to train them? Should they be a certain size? And if so what is the weight limit? I'd like to train my 1 yr.old gelding for my son to ride. My son is almost 3. I was told that they couldn't have anyone over 50lbs on their back. Is this true? If I can find a pony that rides and drives that would be even better, but for now I want to train this one.