Why doesn't my BB thread all the way in?
 

Why doesn't this BB thread all the way in? It says 68mm on the BB itself and the shell is a 68mm (Surly CC). I'm replacing the BB with the exact same model it had before.

Ride like this? Get a spacer? What to do?

If that is a sealed BB that is perfrctly normal. Just means that it is in tight. Find something else to worry about. Roger

Do you have a screw securing a bottom bracket cable guide?

.
...if the aesthetics of having that exposed thread bothers you, you can cover it with an old style BB lock ring.

No screws in the BB shell. It's a single speed setup so I took the cable guide off. The exposed threads don't really bother me. I was just wondering if I should do something about it or not.

did you thoroughly clean the frame's threads with a wire brush?

did you apply a bit of grease to the threads before installing the new BB assembly?

if yes to both questions, then you should quit worrying, and go ride the bike.

the inside of that part of the BB assy. is slightly tapered, to allow for proper alignment and a snug fit.

ride it.

yes and yes. will do. thanks.

...the purpose of those installation cups on a sealed unit like yours is to go in far enough that the tapered inner circumference of the cup fixes the casing of the sealed unit firmly in place within the BB shell. When you put the crank arms on, grab them and see if you can feel any movement when you rock them perpendicular to the plane of rotation.

If not, you're in deep enough and good to go. If you feel some movement, back the thing out and start over.

Totally normal. Finish assembling bike and ride. ;)

Riding it now (doing deliveries) and there seems to be no movement. I backed out it twice trying to see if I could get it to thread in all the way. It went in fine. I've just installed a dozen or more cartridge BBs and never had this happen so... Guess it's fine.

Perhaps, I am being a little anal, but on the bikes I've worked on, the left side of the bike, the cup was screwed on first until flush, then the right side was screwed on. I don't know if this makes a difference.

I wouldn't call that anal, but I would definitely call that backwards. ;)