So I've pretty much cleaned up all the parts on the John Deere Racer and it is looking pretty good. There was much less rust than I thought, and all the parts are shiny. Except one of the cups on the BB is kind of worn on the threads and doesn't look as sound as the other side. It's probably cosmetic, but the boy wants new cranks, and I'm trying to determine if that's possible with this set up.

I've already learned enough to know that putting new cranks on the old chain rings will be a tough retrofit, since the chainrings only have places for 3 stackbolts. (Judging from the sources at my fingertips, anyway.) So if I don't want to retrofit the cranks, that means new chainrings attached to new cranks, which then means a new BB, right?

I know the old BB is British 68 mm. But what does the other measurement refer to? 108 mm, 113 mm, etc.? Which one is appropriate here and how do I determine that?

Also, how do I determine which length of cranks is appropriate? The old ones are 190 mm from end to end but I don't know if they're measured from center to center.

Now I'm going to get my credit card and make a donation, because you all have been so helpful.

Karen