Originally Posted by
ebgbz
I understand about the clockwise and c clockwise and it makes sense. What doesn't make sense is that as I "crank" on this thing it appears to be tightening it in the BB shell.
So...I drew a diagram of the existing condiiton and it looks like to me that in order to "screw' this thing out I have to turn it C Clockwise.
Note the direction of the threads relative to the face of the BB shell. I have exaggerated the pitch, etc. to illustrate the condition. With the frame sitting on the floor, bench, what ever, the arrows indicate the direction. If I turn or tighten clockwise I am turning toward the front of the frame and that
appears to be tightening the cup in the shell. I need some directional help here!!!
Fixed cups on are left-hand threaded* - they unscrew clockwise. As you tighten the bolt by turning clockwise from the outside of the BB shell (on the drive side), friction with the bolt transfers the turning force to the cup, and turns it clockwise.
"turning forwards" is a bad term to use - if you make a full rotation (clockwise or anticlockwise), you'll move the wrench both "forward" and "backward" at different points.
*at least on british/ISO and Raleigh threads they are