Originally Posted by ftwelder

I have built a bunch of kids bikes over the years for kids people that work for bike brands or manufacturers or my own kids. I think a single front ring with guides and a wide range cassette is the way to go up to age 14 or so. Make sure the chain stays are long so chain angle is not too severe. I would avoid drop bars also.

You can redrill and tap new pedal threads in older long cranks. This 20" wheeled DH bike uses 2.5" wide, custom cut trials tires, shortened cranks and down-sized controls. I used the huge saddle so my kid could slide off the back and use one foot down in difficult terrain. I guess it's C&V now, my son rode this at age 10 and he is 23 now.


Picture 038 by frankthewelder, on Flickr