We have a kona stinky 24 for my 10 year old and a Norco b line 24 for my 12 year old. Both great bikes, but the kona comes up much smaller. I built the kona myself as I bought the frame only secondhand. Better this way as the forks are pretty stiff and other bits are not great. It now has rock shox recon air forks and runs 1×9 speed. My son loves it.
The Norco comes up bigger and we have upgraded the forks etc as they were rubbish. It now also runs 1×9 and we also upgraded cranks, brakes and wheels. My 12 year old has had it a few years and loves it. Like I said, bigger than the stinky.
Will post pics when I get home.
I’d say get a frame and build your own.
We may sell the stinky after this summer as it is getting small (my 10 year old is nearly as tall as my 12 year old).
We may sell earlier if we can get a nice xs 26″ dh bike for my oldest, my youngest will then use the Norco.
We are in Norwich if you want to come and try the bikes for size.
Simone