fishthe crank through the bottom bracket.
Balance Bike Adapters cost a fraction of what a dedicated balance bike does.
Don't spend precious time shopping for TWO bikes, one of which will be obsolete in two months. Buy one quality bike and a Balance Bike Adapter.
A Balance Bike Adapter conserves resources and requires less energy to manufacture and ship.
The BBA is easily installed, so that you can begin teaching your child, and perhaps yourself, baisc bicycle maintenance.