So I have a new bar/stem thrown on and it comes back from the shop w/a another spacer on…
I already know what the shop will say (they didn’t mention they did this as I was picking up the bike) that they wanted to keep the height the same as the stem height was slightly different…
Ok. Good enough… If anything though, I’d had designs on removing a spacer; and figured I’d go back and ask about having a couple taken out… the response?
“You need that extra spacer for compression on the headset”
Uh, that’s a new one to me… then again, lots of things are new to me as I’m not too smart sometimes.
If your new stem has less stack height around the steer tube than the previous stem, then an additional spacer would be necessary in order to tighten the top cap enough to properly load the headset. The shop could have also trimmed down the steer tube by the difference in stack heights of the two stems, but using another spacer is a safer move that gives you more options for adjustment. Sounds like the shop did a good job, but they should have explained the difference to you before doing the work (ideally) or, at the very least, when you picked the bike up.
Joe – just put the spacer above the stem. The other poster had the techs right about why it’s there, but there’s nothing sacred about it being under the stem.