Dd is 4 in July. She is a bit big for her current bike seat, which was given to us and goes on the back of dh's bike. We're going on holiday with my dad in May and would like to take our bikes, but I don't think dd will cope with the seat anymore! I have seen some in Halfords which look bigger than ours, and have a heavier weight limit, but I don't know if it's worth getting another one. She's too small for a trailer bike - I can't see her being able to ride one for another year at least, but you never know. DH often cycles to work and takes dd to nursery on route.