Kiddimoto superbike - when to graduate to real bike?

[ChipsnCheese]

DS (3.5)loves loves loves his kiddimoto. His legs do seem a bit long now, and he doesn't look so 'natural' on it. Apparently the upper age is about 6. What do you reckon?

DS graduated to a bike with pedals when he was 3.5. We left the stabilisers on for a while whilst he mastered pedalling. He found it all very frustating to start as pedalling was tricky and he had been able to go scarily fast on the Kiddimoto.

Can't imagine a 6 year old on one!