Do not pet her or give her treats when she cries. You will reinforce that negative behavior. Instead treat and pet her when she's calm. She will eventually learn that being calm gives her what she wants.
I will assume your dog knows basic obedience like sit/stay. If she doesn't, this would be a good place to start.
You need to desensitize her to the trailer. I'd recommend first to do it inside the house. Try to teach her the command "trailer" or however you want to call it. You need to use the most delicious treats (human food) for this. Call her in front of the trailer and say "trailer" and hold the treat on the trailer so that she has to jump and get in the trailer to get it. Once she does, praise and treat. Repeat this exercise a lot before trying it outside... After she knows the command and feels comfortable in the trailer, do the exercise outside. Do not take her for rides yet.
After she feels comfortable getting in the trailer when outside you can try the next step. You might want to ask a friend or family member to help you out here. Whith the dog in the trailer, ask your friend to walk the bike slowly. She'll get nervous here but you have to distract her with basic obedience commands and delicious treats. Very soon she'll forget about the trailer and will associate the trailer with delicious treats.
After she feels completely comfortable on a moving trailer you can start riding the bike. Ride it for a short while (maybe 10-15 seconds), then stop and treat if she behaves properly. Continue doing this, each time for a little longer until she's completely desensitized.
Please let me know how this works for you, I plan on trying this myself some day
