Well, I have some sort of old, black and white Fuji raleigh, and I was riding it when out of nowhere the chain fell off along with the derailleur. I never payed attention to the derailleur on this bike, because it's old and rusted, and I honestly expected this to happen. But now i cant figure out how the derailleur goes on it. I cant post pictures on this site because I'm on my phone, so please email me @ Jason-wofford1@outlook.com for pictures.