How much lower (inches) can a RKC be taken down and still he functional ? Specs say bike is 26.3 inches from factory. & am 5-6" & plan on riding about with my 8yr son. I really like the RKC best but should i consider a soft tail? Is there alot of difference in the ride between them? Money is not as much as a issue as to getting a bike i´m happy with.