The Great Mirror Debate - not quite as big as The Helmet Debate, but definitely an issue that divides cyclists. Effective Cycling^TM Instructors (ECIs) can be found on both sides of the argument because there is no "correct answer". - The decision to use or not use a mirror is a personal one that depends on many factors. Effective Cycling^TM classes, and the EC program in general, are not designed to tell cyclists right from wrong, but rather to give cyclists the knowledge and skills they need to make informed decisions about all aspects of their riding (equipment, clothing, technique, road position, etc.).

Those who use mirrors can't imagine riding without one. They argue that the mirror-less cyclists are blind to the rear most of the time and must sneak a time consuming-and risky over-the-shoulder glance when they need to know what is behind them. A mirror allows them to frequently glance behind while keeping attention to the road ahead. With knowledge of the total traffic situation, they feel better prepared to react if an emergency situation should arise.

In situations where cyclists confront high volume or high-speed automobile traffic (such as a daily commute), and the situation changes quickly, a mirror may be the only way to determine when it is safe to look behind before changing lanes. Mirrors are useful on group rides to keep track of riding companions. Some cyclists experience a decrease in neck flexibility as they age and rely on mirrors to relay information about changing traffic conditions.

Those who prefer not to use mirrors feel that many cyclists become over concerned with the situation behind them. Since statistics tell us that the situation in front is more likely to cause injury than the one behind, there is concern that the mirrored cyclists are concentrating in the wrong direction. Some cyclists become dependent upon mirrors and forget the importance of looking over their shoulder before executing lane changes or other turning/merging maneuvers. Although mirrors will alert cyclists of approaching vehicles, it is not always possible to discern how close they are or their speed. Handle bar mirrors are typically convex, causing images to appear further away than they really are. Helmet mirrors can distort depth perception because the cyclist is looking only through one eye.

Cyclists who do not scan over their shoulders before changing lanes lose an important communication tool with motorists. EC teaches that cyclists with mirrors should still check over their left shoulders when changing lanes or maneuvering into position for a turn so that following or overtaking motorists will know a change is coming.

When a cyclist is occupying the correct lane position and is riding predictably, information about what is happening behind him/her should not change that position (except in extenuating circumstances). If a cyclist is riding in the travel lane because the shoulder is littered with debris, then that is the correct position whether or not there are vehicles approaching from behind. By moving back onto an unsafe shoulder to allow a motorist to pass, a cyclist could hit something, lose control of the bike, and end up in the car's path. As you can see, there are many valid arguments on both sides of the mirror debate. Using one to be aware of the total traffic situation makes sense; ignoring the limitations of mirrors does not. Glancing in your mirror is no substitute for glancing over your shoulder before changing lanes.

Thanks to ECIs Paul Magrath, Dave Spitler and John Waltz for contributing to this column.

Reprinted from "Effective Cycling^TM Notebook" from the League of American Bicyclists.
For more information about the League of American Bicyclists, visit their web site, www.bikeleague.org, or e-mail them at bikeleague@aol.com.