Trig Rogers
I have two bikes for sale that are perfect for a younger junior racer or smaller adult.
Bike 1: Redline Conquest Disc 44cm. This is a great entry-level cx bike. It was purchased in 2014 and ridden for two years before being set aside for my youngest who is not interested. It comes with Tiagra components and BB7 mechanical disc brakes. It is in excellent condition. Craig's list ad can be viewed here :https://portland.craigslist.org/mlt/bik/d/redline-conquest-disc/6655232823.html
Bike 2: 2013 Giant XTC 29er size small, This bike was ridden for 2 1/2 seasons (probably about 5' until 5' 7). and was a good transition from a 24" wheeled bike. Craig's list ad and bike specs can be found here: https://portland.craigslist.org/mlt/bik/d/giant-xtc-29er-size-small/6655233070.html
Let me know if you have any questions and thanks for looking.
Trig