I just got into my possession a 1987 (or 1988? s# is 309256) Trek Elance 400 and quickly noticed that the bottom bracket spindle was longer on the non-drive side than the drive side by about 5mm. never having encountered such before, I just assumed it was wrong and so flipped its orientation while I was repacking the bottom bracket. the chain line was obviously amiss at that point, and so I put the spindle back to its original orientation and was left scratching my head as to why Trek would use an asymmetric spindle when they didn't need to, considering they had to orient it "backwards" to make the chain line correct.

Is there any particular reason this may have been done on this particular Trek, besides my initial thought that they had a surplus of spindles of this size that they needed to use up somehow. yeah, I am also making the assumption that this is the original spindle that this bicycle came from the factory with.