Miniature horses were never bred for riding and should not be ridden by anyone. The smallest ride-able equine is the Shetland pony.
There is no set weight limit to riding a horse. However, horses can carry 1/3 of their weight. If your weight is more than 1/3 of your horses, you can cause injuries and soreness. And eventually the horse will become sway (its back will curve in) with age. People should choose a horse that is strong enough to hold them. Make sure of this to be sure you are not harming your horse.
Only the manufacturer would be able to answer that fully.
The maximum weight capacity of power wheels is 130 lbs. With that being said, a child riding on power wheels can not exceed the weight limit of 130 lbs.
The weight limit for a mountain bike typically ranges from 250 to 300 pounds, but it can vary depending on the specific bike model and manufacturer. It is important to check the manufacturer's guidelines for the specific bike you are using to ensure you are within the weight limit for safe riding.
The weight limit for children riding in the Little Tikes Cozy Coupe is 50 lbs. http://www.littletikes.com/toys/cozy-coupe-30th-anniversary-edition.aspx
I believe that the weight limit was about 100 lbs. give or take a few pounds.
There is no height limit, most horse jockeys range from 5'1''-5'5'', the tallest horse jockey was 6'1''. The qualifications to be a jockey depends on their weight and the discipline or type of racing the horse is used for.
me and my father were around 130KG, but I wouldn't put more then 225ish on as it goes slower with more weight on board. hope that helps :)
No horse should carry more than 20 % of it's own body weight this includes rider weight and the weight of the tack. And fat or overweight horses cannot carry more weight than a fit horse.
18 months
This varies greatly dependent on many factors. First you must consider the breed of the horse (specific breed is important beyond the generalization of pony vs. horse vs. draft) as some breeds are built stockier and for more hard work and endurance. Second you must consider the age and conditioning of the horse, a horse in its prime who has been exercised regularly will be able to hold more than an older or less worked horse. It also depends on the type of riding you intend to do and how long you plan to be on the horse. Some people go by a 20% rule (rider should weigh no more than 20% the weight of the horse) but this can leave room for error based on the factors I've already listed. And some people consider anyone over 31 BMI to be unsuitable to ride, again leaving room for error based on the factors above. But, it also depends on where you plan to ride, some riding center/stables do have strict guidelines (like the two I mentioned or similar). But, if you're riding your own horse, or a friend's horse you need to use judgment based on your knowledge of the horse's abilities and condition and the type of riding you're going to be doing.
If a child is to sit in the front of a car with an airbag, they MUST BE 80 POUNDS!!