Bicycling in Bad Weather With Polypropylene Thermal Underwear, The Poor Mans Lycra

Having polypropylene underwearspent more than 8 years as a bicycle messenger has taught me plenty about how to as comfortable as possible when the weather gets wet. The main problem isn’t staying dry, it’s learning to manage the inevitable dampness.

If you’re simply going out into bad weather for some light activity, or for a 1-2 hour power ride then it makes sense to go either waterproof or just wear whatever warm layers you wear, after all a warm shower is just a short time away. You’ll be generating enough of your own heat so that you probably wont have enough time to freeze. But when you don’t have the luxury of being able to simply head to a hot bath and a dry change of clothes, like when bicycle touring, you have to prepare for it.

The main concept to embrace is that while it’s impossible to stay completely dry when you’re working hard in the rain – you can either get soaked from precipitation or soaked from sweat – it is possible to achieve a balance that I call “optimal dampness.”

The main issue with waterproof clothing is that it traps all the sweat produced when the hard work is done. Waterproof clothes are very good at keeping the moisture out… and in. There’s nothing like the trap of being soaked in your own sweat, because at first it might feel OK, after all you’re not feeling cold when your working, but after about 20-30 minutes of down time, all that accumulated moisture turns against you, and you freeze. Once again, this not an issue for the short ride.

Over time I’ve learned that it’s hard to beat polypropylene thermal underwear for biking in inclement or cold weather. I say this for reasons of cost and practicality.

On a side note, I swear by wool, but it’s sometimes scratchy and usually pricey and you can’t just toss it in the wash with all your other clothes because it will either shrink during the dry cycle or get all mangled and bent out of shape. For this reason polypropylene wins on practicality.

These thermal underwear also win on price. Polypropylene is basically a type of plastic, like polyester. The most inexpensive kind usually comes in dark blue and can be found at most sporting goods and army surplus stores. The higher quality varieties often come in black, but these tend to run a little more. When you want to buy 5 sets for each day of the week, whether you commute in the rain or deliver packages, and you don’t want to spend $40 to $50 for one set, mostly you’re going to find them in blue.

The good thing about the low price is that they are easily replaced when they become threadbare. I think BIG 5 has them, as well as Wal-Mart. At $10 to $20 a set, the price cannot be beat.

If one can afford it, though, a local mountaineering store like REI will have the best thermals money can buy, but as I said before, these sets can be a bit expensive.

Budgetary concerns aside, the main reason I like polypropylene thermals is that they work great. Even on a cold day you can still get pretty hot and sweaty when working hard up a hill. Because the material breathes and the fibres don’t actually hold onto moisture like, say, cotton, they tend to dry out quite quickly. They seem to work a lot like Lycra in wicking moisture away from one’s body, but at 1/5 the cost. When it’s raining, they can also get pretty wet and after about 15 minutes indoors, body heat will make them almost comfortable again.

Another key factor is a nice breathable gortex rain jacket. It lets the water vapor (perspiration) out and keeps the rain from soaking in. It actually aids in the evaporative process started by your base layer. This kind of blows the budget, though.

In addition to putting in years as a bicycle messenger, I’ve taken multiple bicycle tours. Though these trips through planning were mostly rain free, I have spent several consecutive days riding into the big soak. For these days I kept a “wet suit” (the never truly dry damp set of clothing) and a “dry suit” (the set I would put on after I put up the tent and tucked away). The thermals were always the base layer.

Sometimes the weather is just cold with no rain, they seem to do an especially great job of keeping a body warm and fairly dry by means of wicking that sweat away. And if it gets warm again, the sleeves and legs are easily pushed up above the elbows and knees, allowing for some extra heat to escape.

When the weather is cold and wet, my ensemble includes:

1.  A work shirt made of mostly synthetic fibers such as rayon or the like. (though a wool jersey is awesome)

2.  Shorts made out of a thin material. Modern camping shorts made of a synthetic fiber are great, but the butt tends to wear out.

3.  Thick wool socks (your feet still get soaked, but the wetsuit effect keeps the tootsies warm)

4.  Thin walled bike shoes (I’ve been using clippless bike sandals. Tennies tend to fell like two mops on your feet by the end of the day)

5.  A good thin, lightweight Gore-Tex jacket. (expensive)

6.  Polypropylene thermals as the base layer

If you can afford the high quality thermals, they really are the best. They last longer, tend to be thicker and just feel better against your skin, but if you are on a budget, cheap polypropylenes do a great job.