If your bike is equipped with a leather saddle and you tend to leave it outdoors, a saddle cover is essential. Without it, the leather will sag prematurely after getting wet – especially if you ride the bike without letting it dry first. But even many synthetic saddles, if left in the rain long enough, can get soggy – resulting in a wet butt on the ride home. Saddle covers are generally inexpensive and easy to carry around, taking up little room at the bottom of a pannier and saddlebag. If you are wondering which to get, here are some factors to consider.
This may seem like an obvious one. However saddle covers are not always waterproof. Some are designed to protect the saddle from fading in the sun, or to provide a bit of extra cushioning, but have no water repellant qualities. Others are water resistant, but are not intended for all-day or overnight use. Read the product description to determine whether the level of waterproofness is what you need, and ask the manufacturer if this information is missing.
Shape and size
Bicycle saddles come in different shapes and sizes, as do saddle covers. A cover designed for a narrow road bike saddle may not fit over a wide city bike saddle, and vise versa. Some covers are designed with more stretch than others and are more versatile, but overall it's a good idea to check dimensions.
Some covers are designed to stretch over the top of the saddle only, whereas others are designed to also cover the underside. The latter style is useful when you are riding the bike on wet roads, especially if your bike does not have fenders.
If a saddle cover has a slick surface texture, it can feel slippery to sit on. If you want a saddle cover that you can keep on when you ride the bike, look for a matte or textured surface.
Sources for Saddle Covers
If you purchase a Brooks leather saddle, a cover is usually included (not sure whether it is the same cover they sell individually - possibly). However, these covers are not fully waterproof and will not fit all saddle shapes.
On my roadbike, I use an excellent cover that Rivendell used to sell, but no longer does. They've now replaced it with this Aardvark cover, which they describe as equally waterproof and designed to fit a similar range of saddle shapes. I have not tried it, but hear that others are satisfied. They also sell the fancier Randi Jo cover that offers extra coverage and is available in road and city sizes.
On my city bikes I recently started using the Basil Katharina saddle cover (the polka dotted one in the pictures), which the US Basil rep sent me to demo. I know that a number of US bike shops sell these covers in person (try Clevercycles in Portland, Houndstooth Road in Atlanta, Dutch Bike in Seattle and Rolling Orange in NYC) but online they are not always easy to locate. If you do manage to find one (either the Katherina or the Elements series), they are inexpensive, completely waterproof, and available in a variety of patterns. The shape is just right for wide, thick city bike saddles, including those with heavy springs.
I am sure there are other quality sources, and your suggestions are welcome.
Alternatives to Saddle Covers
In a pinch, a decent plastic bag makes for a fine saddle cover. I do this all the time when I forget my real cover at home or am riding a borrowed bike. The trick is to wrap and tie the bag securely, so that the wind does not blow it away. Granted, sitting on a bag-wrapped saddle is sub-optimal (slippery), but it is better than nothing.
A more elegant method for those who do not want to buy a cover, is to use a shower cap. Usually they hold in place, but some choose to attach velcro straps for extra security. And of course, if you are the crafty type, you can also make your own cover from scratch using waterproof fabric and elastic.
Well, I think that pretty much covers it. Lots of options for keeping your saddle dry, for happy riding in wet weather.