The bottom bracket I got is the CNC machined 4130. It's a little more expensive, but I believe it will be worth it. Material has been machined out between the thread sets, and the threads and face are a more precise than the ones I had been getting.
One thing I like to do is thread in a fixed and adjusting cup to test the threads. The drive side or Right side is Left hand Thread (Lefty Tighty, Righy Loosey), while the non-drive side is regular Right hand thread. (Righty Tighty, Lafety Loosey).
The tubeset I'm using is a butted tubeset. That means the thickneses change. The seat tube is single butted. That mean one end is thicker than the other. The manufacture indictaes which side is thicker by dabbing it with a spot of paint. You can also verify this by balancing it. The painted end is the heavier end. and since it tapers from .9mm to .6mm you can easily see the thicknes difference.
The manufacture in this case sends you the tubing specs. In this case the seat tube is 1-1/4" (28.6mm) in diameter and 680mm long. The painted end thickness is .9mm for 102mm, then transitions for 64mm to .6mm, and then goes .6mm for the rest of the tube (514mm)
The thicker end goes on the bottom bracket. Since this is a big frame, I'm going to leave the most material I can and just nip the end from the seat tube Bottom Bracket miter. Join me later after I find my machinst square.
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