a few weeks ago my wife sat on a new rt spyder. she only sat on it a few minutes and had to get off told me her back started to hurt. we have a friend who let her set on his spyder rt with a corbon seat and back rest. she sat on it for at least 10 minutes or more and her back felt good. so it must be the stock seat on the spyder. so that was good. if i bought a spyder first thing i would have to is change out the seat for sure.