Originally Posted by makeinu

Myth: Small wheels are dangerous because they are more likely to fall into potholes and stop short, sending the rider flying.
Fact: No. Wheels do not fall into potholes at speed, they mostly sail over them (falling mere centimeters for every meter traveled forward at even moderate cycling speeds). Moreover, naturally occurring potholes do not have tall steep edges like curbs, so there is no reason to expect a wheel that has fallen in to stop as opposed to roll out as if going over a miniature ramp. The actual danger of a pothole is that the impact may cause one to lose control of the bike as the sideways forces on the wheel surprise or overpower the rider who may then be unable to correct the steering before crashing. If this were not the case it would be near impossible for a pothole to cause a crash with a 26" wheel (or even a 20" wheel) and, yet, we know that hitting a pothole is not an uncommon crash cause. So small wheels are actually safer because they give the rider more leverage to hold the handlebars steady and allow the rider to correct the steering more quickly. Wheel trail can not help in these situations because the self correcting property of trail depends on the interaction between the rolling wheel and an even road, which is literally undermined in the case of a pothole.