We enjoyed a few days in Frankfurt looking around and then prepared our bike and trailer for the journey. All our gear arrived undamaged and we were able to leave our bags at the hotel until our return.
We found a great bike shop to purchase the gear that we needed. Frankfurt is a great place for cyclists - even the CBD has cycle lanes and plenty of places to lock your bike up. There is a cool Call-a-bike service where there are bikes all round the city - you ring a number and get supplied a code to unlock the bike - then you use it and once finished, just lock it up wherever you like for the next person who comes along.