I had one like this but not a Sugino. The "size code" listed on Sheldon's site was stamped on the spindle (scroll down to "Japanese Bottom Bracket Spindles, Traditional Cup And Cone Type"). https://www.sheldonbrown.com/bbsize.html If you want to stick with that type, you can get a replacement here: https://www.sjscycles.co.uk/tapered-...-cone/?geoc=US, or get a symmetrical equivalent cartridge BB.


Your BB appears to weigh 455g so even a Tange or Shimano at 300g... well, I am not going to argue about the weight. I agree with veganbikes where in one of his responses he suggested some good replacements. http://www.equusbicycle.com/bike/sug...hure56%201.pdf