I have a mid-80's Takara made with Tange Champion tubing in excellent shape. The cranks are long and I'd like to change them out to a shorter length compact from the 42/53 that's on the bike. Is there any kind of standard BB size from that time period for Japanese manufacturers? Do I just need to take the bike to the LBS and have them take it apart and measure it? I'm watching several auctions on ebay and many come with BB's included, wondering if there's a uniform bb size I can look for.