Originally Posted by Ranger
Get fit online.
Go to the right hand side of the page and look for mountain bike fit. You will enter a few measurements and get a pretty good estimate of what you should ride. It tells me that i need a 19 inch frame. It just so happens that my LBS fit me with a 19.5. Works for me.
Also know that fit is a bit subjective. However you need to at least get in the ballpark and it sounds like your bike is too big. I am 6'2" if that tells you anything. You can ride a little larger frame if you don't expect to be straddling the top tube. IOW, if you just plan to ride on the road. Otherwise a way too large mountain bike is not good.
With that said, i think i will expirement with a larger frame for me someday, since i mainly ride XC and NO singletrack etc.
Specialized top tubes are pretty low. If he only has 1.25 inch of clearance on a Specialized, the bike is probably too big for him.