Biking With A Baby. After the Infant Carseat?

What to do after a baby out grows the maxi cosi? That is what has been on our mind. As J is rapidly approaching that point. A bit quicker then we expected! She is still just 6 months old though and not ready for the bench. 

Google brings up some options:

Workcycles mounts Bobike minis on the wood bench to help support little ones who aren't ready to do on their own. We can't however drill into our seat or box to mount. 

Photo Credit: http://www.bakfiets-en-meer.nl

Busy Bikes created (two) mount(s) specifically to put a Yepp mini rear facing in the Urban Arrow box.  This is great as we already own the mini. Just not sure if the cost and time to get the mount here is worth it. How long will we use it? We paid $100 for the Stecco carseat holder that sadly would only get 4 months use if we discontinued using it now. I do love how much leg room M would get though. 

Photo Credit:  http://www.busybike.com/en

Wildcard ideas. While googling I saw someone mounted a Phil & Teds double stroller seat in the Urban Arrow bike. We have that. We also have a Phil & Teds SMART stroller. The seat is made of the same material as the Yepp or crocs so great outside use. Bonus looks like it mounts into the Stecco baby holder.

I feel like our SMART seat also matches well. 

If we could continue to use our $100 Stecco purchase that would be great. We would just need to secure them together. Zip ties maybe?! (But M would still lose out on foot room.)

Bonus: using either the Yepp or SMART seat we could put the stroller bunting/sleeping bag in to keep J extra warm. 

So that's what we are working on at the moment.