Comment by cameron_b

The ins and outs of that coaster brake rule provide a lot of wiggle room. My kids started on balance bikes and have moved up to a 12" and 24" ( wheel size ) from Cleary with hand brakes. They missed the regression of coaster brakes and training wheels. Geometry for kids bikes mainly comes down to the scale of the cranks. Small cranks are needed to lower the foot position and center of gravity enough to be 'in scale' with how we tend to consider bike geometry to work, but the shorter cranks also limit the suitability to a shorter leg length, so my kids' Cleary Gecko is pretty small on my 4yo, but she's ridden it for two years.

Small kids need smaller components, but it's hard to make small components reliable and cost effective. I really appreciate the folks who took the time to translate the same darn brake levers used all over the world to a size suitable for a 2 year old's hand. They're the cutest thing and they're the first thing I had to teach my son how to use after he was cooking it down hills on the balance bike. They get banged up first on a fall, they get merciless treatment, and they perform the same way I expect mine or any other to perform.