After looking at my jr t I realized a single crown with regular stem needs a longer steer tube to clamp onto than a dual crown with integrated stem. I have an 18 inch xts moto and am considering buying a used single crown with 8.5 inch steer tube. It looks like it would be questionable on length. Any experts know if it would work. Can the steer tube be less than all the way to the top of the stem?