Too short of threadless BB
 

So this 68mm threadless bottom bracket isn't long enough for my bottom bracket shell. When I try to thread the other end of the bracket it barely catches 2 two threads. It is easily loosened when riding.




Does any know if a longer threadless bottom bracket exist? When I measure the bb shell it comes out to 70mm. Please help!

Sorry brain cramp. Started replying thinking 73mm and just dawned on me that you said 70. Are you sure about that? That would be most common with an Italian threaded BB. What kind of frame is it? What BB are you using?

No worries. Shell is actually 73mm. It's a vintage German Panther steel frame. The threads on the bottom bracket shell are no good so I'm trying to install a threadless or "repair" bottom bracket with sealed bearings. I'm trying to convert this bike into a single speed. I've only seen 68mm threadless BBs.

Its a steel frame. Is retapping the shell not an option?

That is exactly what I would do. Knock off a couple mm on each side of the BB shell and any standard (threadless) BB should fit.

A Type Of Threadless BB shell..
 

Is there a groove , just inside of the edge of the BB shell ?

expect the original BB was held in place with a snap ring..

It is possible to build up a snap ring BB cartridge..

It requires accurately measuring things..




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