Protection from the weather
Protection from the weather is a safety issue. Physical stress due to heat, cold or discomfort is tiring and distracting. You will be less likely to be involved in a crash if you are comfortable and alert.
- The most obvious is a loss of feeling in the hands and feet that affects your ability to operate the controls.
- Being cold or uncomfortable is also stressful and tiring, so you are more at risk of crashing because you are less alert and your reactions may be slowed.
- Finally there is evidence that lower core temperature may affect decision making and emotional responses such as anxiety, irritability, aggressiveness, or detachment (Woods, 1986).
Insulation and wind proofing are the keys to avoiding cold stress. The principle of insulation is to allow a thick layer of air between the rider’s body and the outer layer of clothing.
Close fitting openings (neck, wrists and waist) and covered zippers and other fastening points prevent wind entry and heat loss and are essential to maintain the warmth of the air layer.
Clothing that is too loose may also result in heat loss from wind buffeting that forces the warm air out.
Cold stress can also result from wind chill when wearing damp clothes, particularly leather. This is because, as the wind evaporates the moisture, it draws the heat from your body. There are a range of under wear products made from functional membranes which are designed to draw perspiration away from your skin thus keeping you dry and warm.
Insulated boots and gloves can keep the warmth in your feet and hands. However, this will not be enough if your body is cold because your brain will restrict blood flow to the extremities in an effort to maintain core temperature. If your body is cold, then your hands and feet will also be cold.
The shins of a rider are very exposed to cold, if the shins become cold this will affect blood flow to the feet and therefore the warmth of your feet - so protect your shins.
Chemical heat packs from camping shops can help restore or maintain warmth if tucked inside your boots or wrist straps.
Pressure (eg from tight boots, gloves or wrist straps) can also affect blood flow and will become more of a problem as you get colder. Additional layers on your hands such as inner gloves or over mittens can also help.
- A third of your heat is lost from the neck and face, so use a neck sock or wind proof cover over those areas.
Wet clothing draws heat away from your body. Water conducts heat much faster than air, which means you will get cold, much quicker if you are also wet. Wet weather gear is therefore essential, but rain is not the only source of wet stress. Clothing that is wet from perspiration will also draw heat away from your body. Under wear made from functional membranes is designed to prevent this, it functions as a wick drawing moisture away from your skin.
Wet clothing is a particular problem for motorcyclists because of the additional effects of the wind chill factor. The wind chill factor means that for every 5 km/h wind speed, the surface temperature drops 5 degrees.
Some textile suits do have water proof or water resistant properties, whereas leathers are not so good at keeping you dry because leather absorbs water. However whether your normal gear is leather or textiles, you usually need to add another layer to be protected from rain.
The key to keeping comfortably dry is to have waterproof breathable clothing.
- Lightweight roll up PVC or plasticised nylon over-suits are waterproof, but not breathable. They are useful in an emergency to keep the rain out, but they quickly become very uncomfortable because they keep your sweat in. This results in accelerated heat transfer resulting in overheating in hot weather and rapid cooling in cold weather.
- There are a variety of textile jackets and pants that come with a waterproof or water-resistant liner. There is a difference between waterproof and water- resistant. Water cannot penetrate a waterproof fabric, where as it will eventually soak through one that is only resistant.
Check the fine print.
- Is the garment made of waterproof or just water resistant fabric?
- Is the liner fully breathable, semi-breathable or non-breathable?
- Check the design and construction of the garment. How are the pockets, zips and cuffs covered? Does it have waterproof seams? Will water find its way in?
- Does it allow ventilation in hot weather?
Apart from the injury risk in a crash, uncovered skin absorbs heat directly from the sun causing dehydration as well as sunburn. Dehydration can cause fatigue.
Just as insulation is the key to avoiding cold stress, ventilated cover is the key to avoiding heat stress. The idea is to allow wind to flow through the clothing over the skin to evaporate sweat. Air entry points though vents or mesh panels should be on the forward facing parts of the body with maximum air pressure, but should not compromise impact protection.
The outer layers of clothing should also be designed to reflect rather than absorb infra-red heat from the road surface. The colour of your clothing can make a difference. light colours will reflect, whereas dark colours - such as black - will absorb heat.
There are also some new materials on the market that will improve comfort in hot weather. These include:
TFL COOL LeatherŪ is the result of a tanning treatment which reduces the heating effect of the sun on leather. While ordinary leathers can reach 50C in the sun. TFL claims their COOL Leather remains 20C cooler by reflecting NIR (Near InfraRed) rays. It is the NIR rays of the sun that are absorbed by dark surfaces and transferred into heat energy. Manufacturers using COOL Leather include BMW, Jofama and M-Tech.
HI-ARTŪ is a terry cloth-woven polyester fabric which provides high abrasion resistance to level 2 under the EN 13595. It is used as an inner shell to be worn with a separate outer jacket according to weather conditions (Jofama, 2006). The manufacturers claim this is far more comfortable than other motorcyclists’ clothing in conditions ranging from below 0 C to as high as + 40 C.
- OUTLASTŪ is one of a class of “Smart textiles” with PCM (Phase Change Materials) which are incorporated into clothing and interact with the skin’s temperature to provide a buffer against temperature swings. This is thermal underwear at its best and works to keep you cooler or warmer as necessary.
The PCMs in OUTLASTŪ are minute capsules containing paraffin. The paraffin changes from a solid to fluid state according to whether the wearer is giving off or needing heat. As the body termperature increases, the excess energy is taken up by the microscopic capsules melting the paraffin within. As the body termperature drops, the paraffin turns solid and gives off the stored energy. The technology was originally developed to protect astronauts against extreme changes in temperature but is now available for civilian use. (Outlast Technologies Inc, 2006).
Noise or vibration stress
Noise and vibration can also cause stress resulting in fatigue for motorcyclists. Sustained noise over 90 db(A) can result in permanent hearing damage, as well as minor pain which is very tiring.
The fit and design of helmets and visors can also reduce or increase the noise produced by airflow around your head.
A recent study of 12 well known European brands found that half of the helmets tested produced noise over 90 db(A) at 80km/h, only 2 were below 90 db(A) at 120 km/h and at this speed half were over 100 db(A). None of the helmets tested were below 90 db(A) at 160 km/h, and 9 were over 100 db(A) (Schueler et al, 2006).
Properly fitted earplugs, available from most chemists and industrial supplies stores, can attenuate sound by up to 30 db. Make sure that they are not too effective, you still want to be able to hear the traffic around you.
- Clothing should be selected that does not flap or vibrate in the airstream during riding, particularly near the head.
- Some boots and gloves provide protection from vibration though gel or foam in the areas in direct contact with the motorcycle.
Riding is an athletic pursuit, so clothing must move freely with your body. The weight, flexibility, temperature control and fit of clothing can all contribute to making you more or less comfortable. Keep this in mind when you are choosing gear.
All protective clothing should fit without constriction. If there are marks on your skin when you remove an item, then it may be too tight. If it is too tight it may constrict blood flow causing numbness. This is particularly important for the feet, wrists and hands.
Even with the best gear, riding places a strain on the body which must be managed to maintain alertness.
Siitting in the same position with limited movement for extended periods of time is unnatural and can lead to muscle stiffness resulting in discomfort, fatigue and loss of concentration.
Check Fatigue for more information about rider fatigue and for some strategies to help keep you alert and comfortable.