Hi, thanks for looking at this vintage frame & forks, measuring 23 inches from centre crank to centre TT. I don't know a great deal about this, so if you need any measurements I can take them and message you. From what I can gather Parkes was handbuilt, whereas Sun was mass produced, but I think if you're on this listing, then you probably know more about the history and brand than me. If original, the paint is in remarkable condition given its 60+ years old
