Lot's of good parts there Bao...Frame may be 30-34. Looks 2b badged a "Traveller"...early version. I am not certain but this frame could have been made by Shelby in both the 28" wheel and 26" size as well? Not much information on this. BUT, I would get this bike if you can agree with the seller around $400 or so. I have one of these unusual tight-bar moto frames in my possession now I am working on. Hard to say with those pics, but it could be the same frame as yours but badged "Flyer" with very similar badge shape and graphics. My frame has WIDE seat and chain stays that may be pre-35 which begs the question...did Shelby begin making frames to fit 28" "balloon" and/or 26" "super balloon" tires earlier than thought? Would like to see more 33-34 Shelby examples. Schwinn seems to be the 1st, but there is debate about that still. It would be great if you could get pics of both the reat stay and fork width....as well as the wheel size confirmed as 28"...