Hi I need some help figuring out the correct frame size for a dirt jump mountain bike. I raced bmx when I was younger and did some dirt jumping a few years back but I've never owned a mountain bike. I'll mostly be riding trails with my gf but I also want a bike that can withstand some jumping and abuse. I've been looking at the 17" Kona Shred/Stuff models because they seem to be made for jumping and trails/all mountain plus I found a couple of used ones in 17". I went to my local Kona dealer but they didn't have either model in stock for me to try. I did test ride a 17" Caldera and it seemed to fit pretty well. The guy at the shop said if the 17" Caldera fit then I should go with a 17" in the Shred/Stuff model. The only concern I have is that a few pages I've read say that you should go one or two inches smaller in frame size for a dirt jump bike. So I guess my question is would it be ok to go with a 17" since I'll be using it mainly for trails or should I look into a 15" or 16"? If it helps I'm 5' 7", 170lbs and my inseam is around 31". Thanks for any help you guys can give me.