Bicycle Mechanics - another question - will bearings 'splay' out in a race when compressed?

When you compress a threaded headset using loose ball bearings, will the bearings compress out correctly - along the edges of the race, or is there a chance the bearings might 'double up', and not all of them be along the edge of the race? I can just picture it now, going down a hill and suddenly the fork becomes loose because the bearing moved where it's supposed to be. :-O

Both sides of the bearing are held by the radius of the race.
As long as things are "snugged up" properly, the bearing(s) can't move. (That doesn't mean TIGHT)

The two races are curved such that the balls are driven to the designed track line on both parts. That's why one is sort of a cone, and the other a cup. If you can't imagine this, pick up a pong pong, golf, or any ball of similar size. Cup both hands slightly and press your hands together with the ball between them. It'll e driven to the center and trapped there. That's how the hearing races use curvature to trap the balls in desired tracks.

If any of the balls "doubled up" and didn't fall into the track (which could happen only if you added too many balls) you would not be able to adjust the headset and the steering would bind and be obviously not correct right away.

I imagine its better to have 1 too few balls than 1 too many balls when it comes to bearing installs.

Too many balls makes for a stiffy!

I imagine its better to have 1 too few balls than 1 too many balls when it comes to bearing installs.

Too many balls makes for a stiffy!

LOL.

To avoid brearings falling out of place, use lots of grease to hold them up against the bearing track of the headset cup when assembling.

If a ball does somehow get misaligned, or you use too many, you will notice immediately upon trying to adjust.