Seeing and being seen are...
Seeing and being seen are bigger concerns than traction.
Though I don't like cleaning the bike afterwards, I do enjoy riding in the rain. Some riders, especially here in California where rain is rare, respond to this statement with the sort of reception usually reserved for an announcement that aliens recently abducted the speaker.
After all, why would anyone want to ride a motorcycle when the roads are slippery, it's hard to see and you are getting wet?
"Because," replied Tom dryly, "I'm not getting wet." (Anybody else remember the "Tom Swifty" genre of puns?). I can also see better on a motorcycle than from within a car, and the various advantages of a motorcycle in traffic (superior view of the road, maneuverability, more escape routes, etc.) can pay extra dividends (if you are ready to exploit them) when the roads are wet and drivers are in over their heads.
The key element in being able to enjoy a day riding in the rain is good rain gear. These days virtually all rainsuits from reputable motorcycle-accessory firms will keep you dry in a torrent. The factors that set some apart are ease of entry, conspicuous colors, and comfort. I have a Gore-Tex two-piece suit from Motoport that satisfies all those requirements, though I switch to a Firstgear one-piece design when I also want the suit to provide some warmth.
One of my waterproof Alpinestars, CruiserWorks, or Firstgear boots and any one of several styles of waterproof gloves complete the job. I can ride all day in the rain in complete comfort and arrive at least as dry as if it had been sunny.
One tip here: The inside of gloves seem to stay dry longer if you put the gauntlets under the cuffs of your rainsuit or jacket. This keeps water from running down into the cuffs, but not all cuff-glove combinations permit it.
There is nothing like a hard, biting rainstorm to convince someone of the advantage of a full-coverahe helmet. Rain drops can hurt at 65 mph, so you want your face covered. You may also may not want the dark lenses of your sun glasses. A full-coverage faceshield on an open-face helmet will block the rain drops, but lets more water get onto your face and drip down the inside of the shield of a full-face helmet.
Staying comfortable is important. Soggy socks or water running down your crotch distract you from the task at hand. Furthermore, if you get wet and cold, fatigue erodes that mental edge you need to stay ahead of the traffic around you.
Once you have dressed for the rain, you have only two issues to confront: traction and vision. Traction seems to be the primary concern for most riders, usually because they aren't sure how much grip they have available. While some surfaces--metal fixtures such as manhole covers and bridge gratings, painted areas, and places where built-up oil and grease have not washed off--become much slipperier when wet, you can actually call on a surprising amount of traction on clean asphalt or concrete.
How much? The easiest way to test traction is to feel for it with your rear brake. Assuming you know how much deceleration you can develop on dry pavement before the rear tire breaks loose, you have a gauge of what's available if you repeat the test when the road is wet. This also assumes that you have a reasonable amount (say 3/16 of an inch) of tread depth. If you do this at moderate speeds on a flat, straight road, it won't become a thrill ride. Avoid locking up the rear wheel on a steeply crowned road, where it will tend to slide downhill and out of line.
During my ride to work on rainy days, I deliberately lock up the rear wheel two or three times as I come to stops. Once you have a feel for traction, you should have some idea of how much you can safely ask the tires to deliver under braking and cornering.
You also can do a couple of things to improve traction. Premium aftermarket tires are virtually certain to give better wet-road grip than original-equipment tires. With its new CruiseMax tire, Dunlop says that most cruisers will run out of ground clearance long before they come up short on cornering traction on a clean but wet road surface. Other good tires will provide similar performance. A slight increase in tire pressure also improves the wet-weather traction of any tire. Increasing your tire pressure by five p.s.i. or less helps to cut through the film of water and prevent hydroplaning. Just don't take that to mean you can venture out on bald tires with a bit more air in them.
Some situations should be confronted with extreme caution. Railroad tracks can bite you hard when they are wet. The standard advice is to try to cross railroad or other metal tracks at a right angle, even in the dry. When they are wet, this is imperative. Otherwise, you risk having the tire slip into the groove alongside the track, which will immediately ruin your whole day. Other large metal road surfaces or metal sections running parallel to your direction of travel -- some expansion joints, for example -- are equally hazardous and should be approached cautiously and upright. A thin strip of metal can usually be crossed while leaned over mildly; tires slip then catch again after crossing. However, a large metal surface such as a bridge grate, a manhole cover or a cattle guard, may permit the tire to slip too much to recover traction. Painted surfaces can be almost as slippery as metal.
Places where the oil doesn't get washed away by rian falling on it can be thrilling. Watch out for surfaces where water gets carried in but doesn't fall on the road with the force or in the quantity to remove the oil. Toll booths and parking garages offer a chance to experience this sort of low-traction excitement. There is a highway tunnel not far from my house that's 200 or 300 yards long. The oil in there makes it feel a bit slippery when it's dry. When it rains, the surface is like buttered Teflon. Because the tunnel curves, it's a potentially deadly spot for motorcyclists, especially one who rides in expecting a momentary relief from the wet road.
Turning a motorcycle on such a slick surface demands an ultra-smooth approach. Getting on the brakes abruptly or making a sudden steering input could put you in the guardrail. So you want to be slowed down before you go in there and keep the throttle neutral all the way through --and be ready for cars that might get unstuck and block the whole mess.
That smooth approach to speed and direction changes will serve you well on all wet roads. Initiate your turns a bit more gradually. Downshift smoothly, engaging the clutch a bit slower than usual, and avoid abrupt throttle changes. Get on the throttle progressively. Use a taller gear to reduce the forces reaching the rear tire. Apply the brakes in such a way that the tires are not loaded abruptly. Allow more space to stop or slow down so that you need less. And also make sure that drivers around you have time to react to your moves.
Though it might look better...
Though it might look better at the end of a long ride in the wet, this black rainsuit is going to be very hard to see in heavy rain.
That brings us back to vision. The ability of other drivers to see us could be the single biggest issue a motorcyclist must confront in the rain. With low light, windows obscured, and a streaked and possibly fogged windshield, the driver of a car may have a very difficult time seeing the world ahead. If you are wearing black, or even worse, a neutral color like gray or olive drab, you blend into that gray world. A bright yellow rainsuit is probably the best choice for conspicuity and the single simplest way to make your wet-weather rides safer, though white is also an excellent choice and even better than yellow at night. Fluorescent colors also help during the day and retro-reflective striping or panels on your rainsuit, helmet or a pack also help at night. A visible helmet color also makes a difference at night.
You can confirm this when you are out in rainy weather. Notice how early you pick up a motorcyclist, bicyclist or pedestrian who is dressed for conspicuity. Compare how close a dull-colored person gets before you see him. Also pay attention to how difficult it is to see out of a car in the rain. You may think you are easy to see, but the reality from inside a car can be quite different.
Imagine how much more visible...
Imagine how much more visible a rider in this suit (made in England where riding in the rain is a way of life) will be.
How about your own ability to see? Even with a faceshield that's wet on both sides, you probably have a better view of the situation around you than the average car operator does in the rain. The drops on a faceshield (or goggles) are inside your focal point and are just vague blurs when you focas on the road ahead. However, your view can be impaired by faceshield fogging or a windshield that rises into your line of sight. Unlike a faceshield, a windshield is well out in your focal range, and the water on both sides makes it hard to see through. Rain-X does help disperse water on both face- and, more importantly, windshields.
Anti-fogging solutions and the Fog City Fog Shield(r) effectively stop fogging, although the Fog Shield is not recommended for use at night because it creates some ghost images. Even if you don't have a commercial anti-fog solution, a thin layer of hand or dish soap will stop fog. You can wipe it on wet or dry, then polish it off.
For many motorcyclists, the demons come out on a rainy night. Each of those raindrops on your faceshield or goggles picks up a pinpoint of light from every light around you. Riding behind a windshield that is too tall to see over is extremely difficult, which is why we caution against that configuration. Oncoming cars can completely obscure your vision. A timely wipe of your faceshield can help, but you may be unable to see the road at all for a moment. Puddles may be completely undetectable.
On the other hand, lights that aren't so bright -- such as taillights -- reflected in the road surface ahead can show you features of the road surface that you headlight doesn't illuminate. My preferred strategy is to follow (at a distance that keeps me out of its spray) a vehicle with lots of taillights, watching the point where they are reflected to pick out potholes, seams, or objects lying in the road. Watching the vehicle will also warn you of large puddles, which could cause hydroplaning if you hit them fast enough.
Even at night a motorcyclist has a few aces to play. One advantage of a motorcycle is your high view point compared a person in a car. At night, this allows you a better view of the road surface because you have a steeper angle of view. As a result, it's easier to see striping, and other shallow features. You can also use the reflective qualities of wet surfaces to your advantage. Wet utility wires or tree branches can warn you of a car approaching over a hill or around a corner. Brake lights reflected under a truck can alert you of an impending stop.
Since effective clothing permits me to stay warm and dry in the rain, I enjoy a rainy ride just as much as I do on a sunny day. The air is clean. I can make better progress through congested area than cars can, and I experience all the other pleasures of riding.
Because rain drives other riders off their bikes, I even get a few other advantages. The first big storm of a wet winter coincided with the local winter motorcycle show. Not only were Evans Brasfield and I the only motorcycles out there in the "motorcycle lane," but we were the only two bikes in the free parking area provided by Kawasaki. Everybody else paid five bucks.
Of course, they didn't have a dirty bike afterwards, either.
Art Friedman has a special waterproof bag for his computer, so it can come along on wet rides and he can still get email at firstname.lastname@example.org or Art.Friedman@primedia.com.