Bicycle Mechanics - bottom bracket size

I am trying to replace the stock crankset on my 99 Rocky Mountain Soul with Deore LX, and I learned that I need to replace the bottom bracket as well.

The options for this bottom bracket range in sizes from 073-118 to 068-113. What do these number represent? I cannot find these specs in my documentation or anywhere on the net. Does anyone know what the proper size would be for my Soul?

Also, will I need to replace any other components to ensure compatibility with this new crankset (i.e. chain etc)?

Any feedback is muchly appreciated!
thanks.

Upon further reading of these (some, very intimate) messages about the subject, I see that I need the BB-ES70 bracket! Now, does anyone know which size works in the Soul?

thanks again =)

You can narrow it down significantly by measuring the width of your frame's bottom bracket shell, which should be 68, 70, or 73mm. Then, for a triple chainring, the longest available spindle is generally, though not always, the correct one. (As you have guessed by now, the two numbers which specify any BB are the BB shell width and spindle length.)

Thanks, I will do that.

About the spindle length, does it matter if it's (4mm) longer than the stock bracket?

What is the difference between the ES70 and the ES70-E?
thanks....

If it's symmetrically 4mm longer, it will move your chainline outward by 2mm, which will degrade chain efficiency when you use the larger cogs with the middle or outer chainring. For MOST multigear bikes, the best chainline is obtained with the inside ring clearing the chainstay by just a mm or two.