The ranch I worked at had a weight limit. If you looked too fat, they turned you down flat. If you looked questionable, they asked you too get weighed in their industrial hanging weight and even if you're close, they wouldn't let you ride. I thin the weight limit for a 14-15 hand horse was 220lbs max. If you were taller, not fatter, we had 17 hand horses for that.  Imagine having not only to cart people around all day, then to have to haul this tub of lard around even for 30 mins.