hey thanks for all the replies greatly appreciated and although I was asking about the different groups of gearing I still really appreciated indanas reply so thank you-it help me understand the different words associated with gearing (derailler e.t.c) which all helps in getting to understand bikes. theres a few bikes Im pretty keen on SPECIALIZED TRICROSS 2008, KONA JAKE THE SNAKE, KONA SURLA and the GENESIS SCOTT I have been looking at all of these and I think I'm probably going to go for the first one, what do you all think?