thanks STD for bringing it up. I think the body measurement and proportion has a lot to do with bike fitting. I think I pay more attention to top tube length than the standover height for bike fitting (provided that I have at least an 1" clearance).

Almost every person is proportioned differently, like I am 5'10" and my inseam is 33". That makes my torso little shorter than other 5'10" people. This is why I find it difficult to fit in a Gary Fisher bike. cause, they tend to have longer top tube (I could be wrong, since I have not tested all the available brands). as for the GT bike, the standover is of some concern cause I never rode a bike frame more than 19". But, the main problem is with the top tube, it feels way TOO long for me and puts me in a really uncomfortable position for riding.

STD is right, I felt some lower back problem after riding it for a while. I will take some necessary actions to fit it better. if it does not work, I have to sale it, I will start from $300. if nothing the frame is in great shape and is very strong.

thanks for all the input guys. best regards