Originally Posted by
1speed4me
I can't mock it up. The BB is JIS, the Super Mighty cranks are ISO. If I tried to bolt it up it would ruin the crank (and supposedly stick out 4.5mm from where the last crank sat). I did try, I gave the nut a few turns and it didn't feel right so I stopped.
Edit: I suppose I could put the old Super Maxy back in, but would that directly relate to the Super Mighty?
I believe I now know what I need; 68mm shell, 125mm+ spindle, English thread, ISO taper. I'm out of my wheelhouse here, but I've searched pretty well and can't find anything worth using with those specs.
one of the main issues with using a vintage crank. This is why I chose the dura ace 7400, because the 7400 bb’s are still plentiful. You are correct that this crank is ISO not JIS. Both the road double and the track single, are 144bcd. The track used a 109mm spindle and the road used a rather odd 113.5mm spindle. 125 seems way too long and is certainly not the original spindle length. Any 68mm asymmetrical ISO 109mm spindle should be perfect for setting it up as a single speed or fixed. For maintaining clearence for and inner chainring and an outer bash guard as you have yours setup, a 68mm asymmetrical 111 or 112mm ISO spindle should be what you want. I just have no idea how a 125mm spindle came to be used. My DA 7400 crank uses the original asymmetrical 112mm spindle. Setup as a singlespeed I have a chainline at the outer position of 46mm and 41 at the inner chainring position. With a 111 or 112 mm spindle you should end up with similar at the outer and inner positions.
most 70s and 80s higher end square taper cranksets used similar spindle lengths. Typically 109mm for a track and 112-113 for a road double. Only use I could see for 125 would be for a touring triple setup.