Im not too sure myself :S Maybe she felt like she was betraying Jacob or maybe she just didnt want to crash again! :D

i think its because it was her-and-jacob's thing
and then because edward's bike intimidated her.

I think it's because she liked to spend time with Jacob and if she biked with Edward, that would lessen her time with Jacob. And I also agree with luvrob because it was her and jacob's thing that they liked to do together.

yeah...but i think she got intimidated by his high profile bike too

it looks like you all got it

She actually tells him in the book that she wouldn't be able to keep up with him. He likes to drive fast and his bike was so much newer and faster than hers. She also said that Edward would worry about her too much if they were riding together and it would be too hard for him to watch.

Yeah I think the whole motorbike thing is something that she shares with Jacob and not really Edward. She shares so much with Edward that I think this is one thing she wants with Jacob.