I don’t want to disagree with you parents which is why I did not comment previously but how are all the other bochurim getting to Yeshiva if not by bike? Speak to your parents about what they do
My son also goes to a mesivta in Kensington. He walks to and from Yeshiva even late at night. I insist that he carry pepper spray with him but other than that I don’t think he is in such danger that he can not do it