Good afternoon, and welcome to Wind Management! You are here today because riding your bike down a windy highway blows. (That is the final pun you have to suffer. I promise.)
How can you keep warm and dry and un-buffeted? From handguards right up to the long list of full-on motorcycle windshields, anything solid you can put between yourself and the elements will ease the burden that wind and weather place on your body.
I'm getting beat up out there! What will help me out?
Excellent question. To fully understand your problem, we need to explore drag and resistance. In a short form, the drag equation tells us that the power needed to move an object increases at a cube of velocity. Without getting terribly scientific, we can take away from this that the power needed to overcome wind increases much more quickly than the speed of the bike itself. How does that affect you? Well, the power your muscles need to exert to keep yourself from being blown backwards increases very quickly, relative to the speed of your bike. Exerting your muscles for hundreds or thousands of miles is tiring!
Heat transfer is the second half of the problem. Heat transfer is what happens when moving through ambient air makes you feel colder or hotter. This chart helps to quantify the effects of the phenomenon. Interestingly, we usually think of wind chill only relative to typical cold conditions. But notice that if the ambient air temperature is hotter than your body temperature of roughly 99 degrees, riding at speed actually intensifies how hot you feel. The hot air is being driven into your skin! Take into account the additional heat that a hot, air-cooled engine and safety gear add, and you are practically simmering in your own juices on a summer day.
Furthermore, humidity merely amplifies these sensations. So if it is rainy and cold, or you are sweating bullets in the heat, the transfer of heat is even more pronounced.
Shut up, Al Roker, and tell me how to stop being uncomfortable!
Succinctly, you need something to fight the wind for you, and to keep the wind from transferring heat to or from your body so quickly. It turns out that solid materials are excellent at both jobs. Motorcycle wind management solutions range from a variety of products that attach to the bike, like fairings, windshields, and handguards. They also include solutions that sit closer to the body, like garments designed to block the wind. Finally, there are a few ‘offbeat’ hybrid solutions like HippoHands.
Items that attach to the motorcycle are better at fighting drag because they can be more rigidly mounted, and due to the direction of travel, will also keep wind and much of the airborne precipitation from contacting your body.
Great, so I need a windshield. I knew that!
Well, you might. Bike-mounted wind management pieces fall into one of a few categories:
- Windshields: The classic "glass-on-a-bike." Someone who drove a car with a windshield thought to make a tiny motorcycle version, and the touring bike was born.
- Fairings: Cheating the wind was pioneered (like many motorcycle developments) by racers. Long ago, people knew that aerodynamic shapes and flowing curves moved wind efficiently, and with the advent of wind tunnel testing, design ideas are proven out more quickly than ever.
- Handguards: Arguably the cheapest wind-managing bike bolt-on, they offer great bang for the buck because extremities tend to suffer temperature drops quicker than the body’s core.
Well, I still need a windshield, I think. Or maybe a fairing. What's the difference?
Well, not all Harley-Davidsons and other cruisers can accommodate a fairing, but nearly all of them will accept a windshield. Traditionally, fairings are opaque because they do not fall in the rider’s line of sight, and windshields are either transparent or translucent. Factory-issued fairings that are commonly seen can either bolt to the forks (typically called a batwing fairing) or to the frame of the bike (called a shark nose). They are usually designed exclusively to direct wind around the rider in various positions, and seek to direct wind off the rider’s head, body, and hands. Most Harleys also have a small windshield attached to the top of the fairing. Aftermarket offerings include "bikini fairings," which are very, very small fairings that are usually style-driven and shroud the headlight. Originally seen on 1970s and '80s-era sport bikes, they’ve picked up popularity lately with those putting together club-style bikes. Aftermarket full-size fairings for Harleys almost always tend to be batwing style, as fork mounting is typically much simpler than mounting a fairing to the frame.
Windshields, on the other hand, are designed to protect the rider’s body and head from wind, moisture, and temperature, and typically less attention is paid to the hands. Since their glass usually falls in areas that either are or could be in the driver’s line of sight, they are made clear.
Well, what should I look for?
A good fairing or ‘shield should be constructed of high quality materials. ABS plastic is a popular choice for fairing construction as of late, due to its low cost and high strength. Fiberglass, once the king of the road, is mostly being edged out due to the weight penalty it imposes, but it still is an excellent material for creating flowing shapes, even if it’s a bit dated. If you want your new fairing to look integrated, selecting one that’s been prepped for paint can save you or your painter a lot of headaches, labor, or money. Be sure you or your painter has a copy of the manufacturer’s instructions. Some fairings need to be prepped and painted in a particular way or using particular products to look their very best.
A good windshield ought to be made from an impact-resistant material like Lexan, a polycarbonate, or Lucite/Plexiglas, an acrylic. The safety of both can be debated. Lucite/Plexiglas usually provides better clarity, which could provide a modicum of safety, but Lexan edges out Plexi and Lucite in terms of impact resistance. It usually bends in applications where Plexiglas might shatter. Lexan has a higher abrasion resistance, which means it is harder to scratch than Plexi, but the other side of that coin is that it is harder to buff the inevitable scratches, nicks, and swirls out of Lexan than it is for Plexiglas/Lucite.
Mounting is a concern, too. Ideally, you want mounting hardware that is made of aluminum, stainless, or incorporates a method of protecting the base metal if it is steel. It’s almost certain your hardware will see some rain! Additionally, unprotected metal can fatigue, putting you or other drivers on the road in harm’s way if the ‘shield comes free of the bike from rust or corrosion. If you are going to remove your wind protection device from time to time, hardware that allows quick removal and mounting can be a good idea. It’s pricier than a hard-mount system, but many systems allow to switch quickly from a fairing or windshield for longer rides or an uncluttered look for day-to-day riding.
Of course, fitment is important as well. A manufacturer may charge significantly more for a bike-specific kit to mount your fairing or windshield, but the installation will be a snap, and little to no fabrication will be required to make things work correctly. That extra money may well cover the cost of frustration or an afternoon of not riding!
Are there any advantages to one or the other?
It depends what you like! Fairings offer some neat features, like the ability to customize the height and color of the small screen attached to it, without replacing the whole dang fairing. There’s also the ability to put storage inside the fairing, and accent the ‘wing.
Smaller bikini fairings are usually a snap to install, and really change the style of your bike. Clip-ons, a bikini fairing, a two-into-one pipe and rearsets can turn a plain-Jane Dyna into a cafe ripper. If you experiment, you can usually find a little “sweet spot” on the bike that offers a bit of respite from the wind and noise.
You can tuck in behind a windshield in the event of seriously cold or wet weather. They come in a myriad of colors and heights, and if you’ve got a traditionally styled bike like a Heritage or a Road King, these shields are almost a no-brainer.
I've heard I am not supposed to look through the shield. Is that true?
There are mixed opinions on this, but the great majority of touring riders look over the shield, as opposed to through it. The shield sometimes distorts vision, and is often dirty or scratched, further reducing visibility. It sounds strange, but because humans have horizontally-oriented vision, we do not need nearly as much vertical field of view as you might think. If you want to test how it affects your ability to see prior to pulling the trigger on a new windshield, you can use this test as a rough guide: put a piece of duct tape on the bottom edge of the visor on a full-face helmet to simulate how the shield will affect your vision of the road ahead. (If you choose to do this, be careful! A long, lonely parking lot is a good test area. As with all things moto, use good judgment.) It’s not going to give you a hard-and-fast rule about what height to buy, but it will help you determine if the glass is going to bother you when in your field of view.
Can I install this myself?
Probably. Simple hand tools like wrenches, sockets, extensions, and hex keys are usually what’s required. A very few bikes require relocation of turn signals, but for the most part installation is not terribly difficult. If in doubt, see your local motorcycle shop. They do a lot of these installations because they are popular with many riders!
Do you guys rock them?
Sort of. Plenty of Zillans have shields on their metrics. Of the three H-D products that show up in the RevZilla employee parking lot, only one is set up for long-range missions, and that rider (surprise!) has a good-sized windshield.