I'm glad we have this forum.
Here are some pictures of my son on his current, small bike. I am building him a new, larger bike. I'm looking for any thoughts or criticisms of his position on the current bike, that I can use when picking frame size, components, and building up the new bike.
Noodling along on the tops (there are interrupter brake levers there)
Pretending to go fast (but actually coasting) in the drops
Actually pedaling in the drops (and getting tired of riding back and forth while dad takes photos)
The current bike, pictured, is a junior sized early '70s Peugeot with 26"/559mm rims. It used to be my old bike, when I was a kid, but not much besides the frame is now original. The frame is 19" (49 cm) center-to-center. As shown, the pedal-to-saddle (distance from pedal upper surface to midpoint of saddle upper surface) is 33.5", and, I think, he needs around 1" more (but the post is maxed out).
Obviously, his new bike will be larger. It will be a small adult bike with 700C wheels.
I've tentatively picked a new frame (call it frame A) that is 20.5" (52 cm) center-to-center. That will give him 34.5" pedal-to-saddle with a bit over a fistful of exposed seatpost (about 6"). He should be able to stand over it pretty comfortably, though we haven't tried yet. However, with frame A, he won't have near the saddle-to-bar drop that he currently has. The top tube will be significantly longer than his current bike.
The alternative (call it frame B) is 19" (49 cm) center-to-center. So, not larger than his current frame, but this one is an adult frame for 700C wheels. That frame would allow a larger saddle-to-bar drop, and the top tube will be shorter, than frame A.
Any thoughts? Is his current riding position one that you would try to replicate in the new bike, or should I be trying for something else? Would you go with frame A or frame B?
The usage is weekend fun rides. We'll ride Seattle to Portland in July. He doesn't ride this bike to school/on errands, he has a hybrid for that.