Let me give you a tip:
You can stop using them (unless it's a Euro)
They create more problems than they prevent and end up adding unnecessary weight (some are steel vs aluminum)
I've noticed bearing wobble that went away once I took mine out. And in case you are wondering, have not had a single bearing failure in 2 years. Neither me nor another long time pro who rides for Hoffman (and he has been running his cranks without the spacer for YEARS)