One of my pet peeves... out riding, get a flat, fix the flat, now tire is out of balance and the bike shakes when at speed - especially annoying if the tire is relatively new as it is a PITA to take the wheel off the bike and to the shop just for a re-balance.
...or you throw some knobs
...or the tire changes balance as it wears
Finally got around to picking up a balancer/truing stand
