How Do You Teach A Child To Ride A Bike Without Stabilisers?

Many children can learn to do this by the age of 3-4, the key is having a bike that is small enough.  For the child to learn to balance they need to feel safe trying to wobble along.  This means that the bike seat should be low enough that the child can sit on the seat, straddling the bike with both feet flat on the ground.

On such a small bike the child can literally run along, occasionally (when the feel confident) lifting both feet to enjoy coasting.  Ideally the bike shouldn't have any pedals at this stage, as they just get in the way of running along.  Metal and wooden 'running' bikes in child sizes and without pedals are widely available on the Internet.

However, a young child can learn on an ordinary small bike with pedals.  Especially if they are already used to pedalling (from using a tricycle or bikes with stabilisers).  The key thing is that the child must KNOW that they can get their feet to the ground fast and safely, to stop themselves falling over.  Also, it will be easier to start off if they can get a really good push off the ground.  

Once they master riding without stabilisers on a too-small bike they can move up to a bike that is the right size for their leg length.