Full Title: Best Bottom Bracket for every Bike - the End

Scope: He starts with BSA and evolves it goes thrdiscusses best press fit and threaded. He starts off by telling you the BSA was the best standard, so why change? Because of carbon fiber won't take threads. To get around that, they had aluminium inserts glued in. But then went to directly press fit the bearings into the frame, lighter and simpler. The nominal diameter is 41 mm. So he says every bike shop should have a 40.98 reamer, to make the 41 mm hole. (this is high end carbon frames that come without the bearings).

Then needed a bigger hole, so the industry went from 41 to 46 mm. 46 mm can take decent sized bearings no matter which system you use. That leads to T47 external and T47 internal. (47mm is 1 mm larger than 46). You are cutting threads into the carbon frame?

So the concept here is that in these high end bikes, the bike shop is building up the ultimate bike from a high end frame. Totally beyond the scope of our standard bikes.

This video explains advanced bottom bracket systems that are beyond the scope of our "standard bikes". So this video is for interest only. He compares and comments on all the different systems.

Mapdec Cycle Works is an british cycling workshop, so he has examples of all the frames, etc.

This video is something you might view if manufacturing a "standard bike". You would choose BSA. You might choose Chris King because it is serviceable, rather than the typical Shimano BB-UN55.