I am a keen cyclist and cycled 5 (hilly) miles into work every day before going on mat leave. DS now 10 weeks old and I am keen to cycle with him (not to work but loads of cycle paths near me). I can't seem to get a straight answer but could someone let me know if this is right. Seats on bike 9 months + trailer 12 months+ . Only option at present heinously expensive Dutch 'cargo bikes' which you can attach isofix car seats to?