I am installing a 600 crankset from an Arabesque group. The original BB spec is, I believe, 116mm. I'm not sure that's pertinent, but I know someone will ask.

I had a 118mm UN-55 BB laying around so I did a test installation. I didn't measure the chainline, but I can tell you it's too far outboard. I have 7mm between the inner ring and the stay, and, given the gearing and the combinations that will get the most riding time, I would like to have a clearance of 3 or 4 mm.

The 118mm unit has 21.5mm of spindle on the driveside, measured from the outer edge of the mounting flange. So my question is, does someone know which UN-55 length would have a drive side length of around 18mm?