Dude...I'm 6'2 my frame is 18.9 and the city I live in is all hills. I keep up with traffic.. And my knees are fine, well better then when I rode street. Your shins are another story missing the pedal isn't all that fun.
DOOOOOOOOOOOOOONOTTTTTTTTTTTTTTTTTTTTTT GET A DK SIGNAL!!!!!!Seriously my friend got one and well I mean it's a good bike and all but you're gonna NEED to upgrade it sooner or later and It'll end up costin alotSo i'd suggest getting a WTP Metric or OG Balance 3. I started with a WTP Metric you can still bunny hop and 180 or 360 and it won't break or weaken at all. Get a Metric!!!!
Dude, its just a bike...you buy it and get use to it.