I agree with BB - use the website URL, but maybe use an interesting font - not italicised but Tahoma, squire something like that with a clear (transparent) background so you can stick it over original paintwork. Possibly print in a few different colour options - silver, black, red, white so you can overlay against your bikes paintwork. I have a silver aprilia and silver stickers look really trick 8-)

Highlighting the word BIKER does look better tho 8-)