150r would be way to small. A 250Fflyingfuzzball said:i would look at a crf150r
it is good for the track and trails.
lots of power for a beginner and as hughes mentioned bikes are way different then quads.
The RB would still be to small. My dad's 5'7 and He's to big for my 150 and for the 150RB. He should go with a 125 or 250F.flyingfuzzball said:hes 5'7"
the rb would be perfect for a beginner bike
but he would out grow it.
if he wanted a bike to not out grow for awhile then he should get the 250f