Originally Posted by
obrentharris
But isn't the steerer tube constrained from bulging by the spacers (assuming a snug fit) unlike down in the head tube where the nearest constraint is the headset bearing top race?
Brent
No. Those spacers have plenty of clearance and drop on. They work on unthreaded steerers that have a larger diameter because threads are cut.
By the time the thread tops would touch the spacers, the bottom of the thread grooves will have already cracked.