An idea has been floating around some of the smaller industry players for about a year now. Brands like White Industries, Chris King and Paragon Machine Works were all thinking that people liked threaded bottom brackets, but that frames and cranks had changed so much over the past decade, getting larger diameter tubes that didn’t go as well with the tiny English threaded BB. These ideas progressed in distinct conversations running their own courses until one company contacted another to make a bottom bracket, and then everything really fell into place to (hopefully) replace the pressfit bottom bracket.
The driving force was to take the advantages of a 30mm spindle and modern frames and combine them with the proven durability, quiet performance and lovability of the traditional threaded bottom bracket.
The result is a new standard called T47, for “Threaded 47”. It measures M47x1, meaning a 47mm outside-thread diameter with a 1mm thread pitch (25.4 tpi equivalent). That puts it very close to the 24 tpi (threads per inch) currently used on English threaded bottom brackets, so it’s essentially been proven on bicycles for many, many years. And that slightly finer thread pitch helps to manually hand tap and chase the threads, a handy feature for frame builders.