Originally Posted by Zuber
There is no exact standard for just the spacer. But, all the spacers and the spring should be 513 mm long. You may have different spacers on each side if the springs are different length. Not often though.
That explains why I had 2 thick spacers (1 in each tube) and then only 1 thin spacer on one side. I thought the factory left one of the spacers out, I didn't bother to take an overall measurement with the springs, anyhow I was in there to change out the springs to heaver ones, hopefully it don't make much of a difference or maybe that's why I crashed in the desert
(see above post).