This is a gear specifically for this bike:
https://www.amazon.com/gp/product/B07PJNJLQT/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8
"XJD 5 in 1 Kids Tricycles for 12 Month to 3 Years Old Toddler Bike Toddler Tricycle Boys Girls Tricycle for Toddlers 1-3 Baby Bike Infant Trike with Adjustable Seat Height"
Basically the rear wheels attach to arms, those arms have teeth and pivot around this point. The white button pushes down the spring and pin.
You may have to drill the holes slightly deeper.
| XJD_5_in_1_Kids_Tricycle_rear_wheel_lock_v3.stl | 109.7KB |
