Iv a 7yr old riding a Beta 50,
the frame is heavy and he is only getting used to the clutch, it’s ok for riding through the mountain roads and fields but trials stuff he struggles with the weight,
he does have an Oset 20R and he does his trials training on it, ideal for his size,
would recommend these bikes,
do not buy a Vertigo 50, I had a brand new version and it gave a lot of trouble ended up having to bring it back to the dealer,