Wobbly wheel - spokes or bearings A little while ago my son's bike had a wobbly rear wheel. I tightened up some spokes which improved the problem but didn't remove it. Eventually I took it into my LBS who immediately diagnosed a problem with the bearings.

My question is whether a wobble caused by loose spokes looks different from a wobble due to a problem with bearings.

Thanks

Chris
If you spin the wheel by hand with the bike off the ground, then side-to-side wobble is also called "out of true" and is caused by spoke tension, or an impact while riding.  Wheel going badly out of true on final tightening 

On the other hand, if you hold the non-spinning rim in your hand and move it left/right while mounted in the bike, there should be no play discernible or visible at the axle.  If you feel motion sideways, then its bearings malajusted. How do I know if my cone/cap/bearings need to be adjusted?

A wheel can have both, or ideally neither, or either.