Definately not a small. My friend who is 5’9″ has a medium and it is too small for him. I’m 5’8″ and medium suits me ok, but I prefer did prefer very small frames. I would definitely try one first, if you have ape like arms a Large might suit you better.
I would never ever buy a YT though! The only thing that hasn’t been replaced on my friends bike is the frame, but that has an oval headset cup that the bearings rattle in, they said is normal. 2 Months for replacing each parts is pretty poor (shock x2, forks x2, BB, Seatpost x2, Wheels).. That’s over 6 months his bike has been in bits on the floor awaiting replacement parts. There are a lot of people who have not had a single problem, I’m sure they will mention it after this post. 😆
😉
It is a good bike though, when it works.