Originally Posted by
El Chaba
In reality, you could descend a twisty mountain road on a tubular with no glue at all as the tire will always be forced against the rim......but then all bets are off when you hit a road imperfection or piece of debris that causes a hop and the tire is side loaded upon landing, so I opt for a pretty secure gluing job.
A good glue job keeps the tire from rolling off (yes, the fear of this is out of whack with the reality); keeps the tire from sliding along the rim when braking (making the valve crooked), and keeps the tire on the rim when you flat - that's the part that I worry about most... coming down twisty mountain roads.