i bought the 30" since that was what the vast majority of them were. i did a quick measure and it seamed reasonable, but now i think the 28 might be what i need. my knee will JUST rub the back of the wheel when i lift my foot high for the brake. and i'd love for it to only stuck thru the firewall by almost nothing.
i'm a 6'3" 275lb dude though. my 5'8" wife wants to move the sear fwd like 1-2", but no way i'm putting in sliders