OK -

So I have a new Voodoo Wanga in my bike stand that I have been building slowly. King Headset. Just bought a Paul Word Disc hub and am having a wheel built. Says that it has 51.5mm chainline.

Now I'm poking around for SS cranks and BB and I want to make sure I end up with a good chainline. What am I looking for? How do I make sure I buy cranks/bb that have a 51.5mm chainline? How many mm away from 51.5 can my chainring be to still have a good chainline? Can I adjust the chainline of my chainring after I buy the cranks and bb?

I'm going to go poke around Sheldon's (rest in peace & thanks for all the help) site. But if you have advice for me I would be grateful.

Thanks,
Ed

Sheldon's (may he rest in peace) chainline specs for double and triple cranksets all quote values for the middle position that results from mounting the crankset on the manufacturer's recommended bb length. On a triple this means the figure Sheldon gives is for the middle ring, and on a double this means the figure will be for a plane right in between the two rings. This means you will have to do a little fourth grade math to figure out what the chainline will be on the ring position you are planning to run. From there, if you need to get closer, you can use a different size bb spindle than the one that the manufacturer recommended for multi geared applications. If you do this before buying your cranks and bb, you'll get something that will probably work on the 1st try.

Some people over here will be able to help you, but generally SS MTB questions get better answers over in the MTB forum.