I am planning on changing my bb. I searched and know about the UN72 . I called my LBS and they said that a UN54 will work, and that they can get one UN54 for $20. During my searches I ran across someone suggesting to us the UN54. Has one one tried this one and how is it holding up. I would like to put a double on the front.
Also, is it possible to keep the orginal cottered spindle and just add a cottered double chainring. I now have a 9 speed squeezed ( took two of us ) on the rear. The first cog just barely scraps the chainstay, so I will have to take it back off and put a spacer on.