Full mudguards are typically wider and often longer than clip-on guards and have a specific fit, offering better coverage as a result. The longer the mudguard, the better the coverage, and guards with mud flaps (rubberised sections at the bottom of both the front and rear mudguards) generally provide more comprehensive protection than those without.
Needless to say, look for road-specific mudguards for your road bike, rather than those designed primarily for trekking or mountain bikes, as the width of the guard will vary according to the width of the tyre, which impacts on the coverage it provides.
Some full mudguards are available in a variety of widths. The SKS Bluemels, for example, are available in ‘narrow’, ‘wide’ and ‘hybrid’ widths, for 20-28mm, 25-35mm and 28-38mm tyres respectively. Clip-on guards typically come in one width, though SKS also offer the Raceblade in a ‘long’ version.
