Hi, have been cycling with DD in a burley cub since she was 8 weeks old. She's been in her car seat til now, but is now 9 months old and I'm thinking of having her in the trailer seat alone soon. However, she's quite small and her head is too small for most of the helmets we've tried. (Down to 46cm) Spotted the wee-ride spike that goes to 44cm on amazon- any good? Anyone have any other suggestions? I guess we could keep her in the car seat til her head grows a bit, but it'd be nice not to keep moving the car seat around.