I just replaced a punctured tube on my youngest boy’s bike and did some minor servicing and adjustments.
My boys are aged 4 and 7, over the last few years I have bought three bikes for them from two different bike shops, one being a well known high street cycle chain, the other a very well established independent. All three bikes were from major manufacturers and at the higher end of pricing for childrens cycles. What surprises me is how they let bikes out the door with set up that would not be tolerated on an adult bike.
The first bike, Ben's "MTB" had brake levers poorly adjusted for small hands and brake pads not aligned well at all so braking power was really poor.
My youngest, Noah's, first bike was a runner bike, one tyre was fitted with the incorrect direction, not a big issue at all but still shows a lack of attention, it was the most recent bike purchase that concerned me more.
This was my youngest's first proper bike, a Ridgeback. The rear brake was out of balance and adjusted so close to the rim that it rubbed on the out of true wheels. The wheel was poorly alligned in the dropouts and together with a rear freewheel bearing that was stiff to the point of being faulty, it would not have been much fun to ride. Finally the chain was strangely dry, it appeared to be completely missing any factory or other lube that I would have expected.
None of the bikes were dangerous but it does make you wonder what else could be missed with such poor quality control.