Think about everyday handling
A lighter bicycle may be easier for a child to push, lift after a tip-over, maneuver at low speed, and carry over a curb. Geometry, tire choice, gearing, and component proportions still matter alongside weight.
Compare complete and consistent specifications
Check whether a published weight includes pedals, kickstand, reflectors, or other equipment. Compare the same size and configuration, and remember that larger wheels and gears may add useful capability as well as mass.
Treat ratios as brand guidance
Some children's-bike makers publish a suggested bicycle-to-child weight ratio. That can be a useful comparison tool, but it is not a universal safety limit. Follow the exact maker's rider-weight and intended-use limits.
Prioritize fit and control together
A very light bicycle is still the wrong choice if the child cannot reach the controls or use it for the intended terrain. Evaluate weight only after confirming fit, braking, stability, and age-appropriate use.