We have a Harley and took Autumn when she was about 3 years old. She was scared......I think the rumble of the bike is too noisy for her sensitive ears.
We went to a Fall Harley Ride a couple weeks a go and there were quite a few people that had their dogs with them on the bike. They were bigger though, like maybe 10 lbs............I talked to one Lady that had a Yorkie. OMG I felt so sorry for that dog.........The fur was matted so bad and looked like it desperately needed a bath!