Home of the Winter Cyclist

And Other Crazy People.

ICEBIKE Tights!!
- Gotta Have 'em!

Strategies

Footwear

Base Layers

The Lower Half

Winter Rain Pants

The Upper Half

Head Gear

For the Hands
Icebike Mitts!!

Icebike Eye Wear

Figuring Fabrics

Winter Wear -
Tested On Ice

Search Icebike
Back to Clothing
Back Home 

Figuring Fabrics

Selecting winter cycling clothes is hard enough with the need to be warm but not too warm, tight enough not to flap in the breeze but not binding, and water wicking but not water absorbent.

The task is made worse by the never ending selection of fabrics with magic bullet names, mountains of hype and advertising claims and expensive price tags. How can the average cyclist have time to determine what's true and what's hype? Which manufacturers claims and counter claims should you believe?

Here we set out to gather all of this information in one spot. We will provide links to manufacturers pages where possible, and we will attempt to explain the buzzwords.

Wicking Fabrics - The base layer

You often hear that a wicking under layer is important and an absorbent under layer must be avoided.

So what's the difference? Absorbent fabrics soak up water and hold on to it. Wicking fabrics transfer water somewhere else, without absorbing it. At least that's the claim.

All wicking fabrics rely on capillary action, often combined with water repelling coatings of the fibers. Most are some form of polyester, the only major exception being polypropylene. Some are microfibers.

(Microfibers are not a fiber unto themselves. It is a technology developed to produce an ultra-fine fiber, and then weave it or knit it into a very high quality fabric. DuPont introduced the first polyester Microfibers in 1989.)

Capillary action (wicking in the truest sense) will attract water from locations where it is abundant and transport it to areas where it is less abundant. When all parts of a garment are equally wet capillary action ceases.

Normally water in a fabric tries to coat all parts of each fiber. This seems to be water's task in life.

If the fibers of the fabric can be made water repellant, rather than have the water cling to each fiber, it will have nothing to hold it in place and will act like water on the hood of a waxed car, it will essentially try to bead up. If the structure of the fibers is such that it is conducive to wicking (long parallel strands) then capillary action will pull this water in all directions where lesser density of water exists.

Most fabrics that are touted as having good wicking characteristics will cause a single drop of water to bead up when dropped onto the fabric. Try this on some Thermax or Capilene and the bead will sit there for some time - minutes in some cases. If the water drop hits a fabric surface that is not horizontal it might just bead up and roll right off. On cotton, the single drop of water will instantly disappear into the fabric. Polypropylene does not wick very well, but will absorb a drop of water quickly.

Now you might think that this would indicate that the Thermax or Capilene would be a poor transporter of water since it tends to repel water. You might think cotton and Polypropylene would be good wicking fabrics The truth is that capillary action is a weak force, and if the fabric is to wick, it must have no affinity for the water. Cotton has a great affinity for water. It soaks up water quickly - and holds on to it, keeping it near your skin.

It seems likely that department store personnel will take a very dim view of your dropping water on garments on the shelf, so do these tests at home and be prepared before you shop.

Wicking In Winter

Wicking fabrics tend to move perspiration away from the source (you) to any place dryer. It is not unusual to find the outer garment soaked and the inner one comparatively dry. This is because unless it is warm enough for evaporation to take place, the upper layer is as far as water transport can go before colder temperatures slow it down. This saturation will eventually work backward , building water closer and closer to your skin. When that happens, you are going to get cold as soon as you stop exercising.

Warmth Fabrics - Mid Layer

If this page dealt with natural fabrics, high on the list would be wool. Still a good choice for cyclists, wool middle layers provide excellent thermal properties and keep you warm even when wet. However you know wool.

The news these days are in the newer "fleece" fabrics. These fabrics are tightly woven meshes, usually of Microfibers that provide air entrapment, wicking and high insulation properties while retaining light weight.

Probably the best known is Polartec from Malden Mills, however there are several others such as Synchilla fleece, Capilene fleece, etc. Some of these are made from recycled soda bottles which are melted and spun into polyester fibers.

These fleeces are far lower maintenance than wool, and they dry quicker and provide wicking so that moisture wicked up by your base layer is moved away from you. Fleece garments don't shed water very well and usually require a shell of some sort.

The other "new" insulation fabric is Thinsulate, by the 3M company. New is in quote because it has been around for in one form or another since 1978, although new varieties are appearing regularly. Thinsulate is a blend of polyester and olefin (neither of those terms are all that specific, but it is hard to pry these secrets from big companies). Thinsulate is a Microfibers material and can often be found in some of the same types of garments as fleeces. Some Thinsulate is recycled material.

Warmth In Winter

I'm not aware of any issues with these newer fleece fabrics in winter use. After all that is precisely what they were designed for. The even work well when wet. The only problem is that they are not real durable and need a shell to protect them, and they can pick up odors if not washed frequently.

Breathable Fabrics - The Outer Layer

Breathability, is the ability of a fabric to pass water vapor while blocking water. It does this usually by having micro-pores, holes too small to allow liquid water in, but large enough to allow water vapor out.

One would think that a molecule of water is the same regardless of its physical state - one Oxygen atom bound to two Hydrogen atoms. True enough, but in the liquid state there is the stickiness of the molecules themselves, (they tend to clump together), and surface tension. These two forces (maybe they are the same force by different names) combine to prevent the passage of liquid water through the membrane. Apply a little soap to the outside of any microprobes fabric (thereby destroying surface tension of liquid water) and your rain jacket passes water just like cotton.

These micropourous fabrics (Gore-Tex being the prime example) work on a partial pressure differential between the sides of the fabric. It must be more moist ans warm inside the jacket than it is outside the jacket or it will not pass water vapor in the preferred direction.

Also any accumulated rain on the surface tends to block the holes preventing the breathing effect that we are counting on to carry away water vapor.

However, it is a common misconception that as soon as you get the outside of your Gore-Tex cycling jacket wet that all breathing ceases. This is not true, because your Gore-Tex is not wet, just the shell. The Gore-Tex is actually sandwiched under the shell, that it, it is laminated to the base fabric, which is usually nylon and always treated with a water repellant finish. It is far too delicate to serve as an outside layer. It is also too delicate to serve as an inside layer, so it is usually protected by a sewn in liner. (You can see the actual Gore-Tex by looking at the inside of the shell if you can find any place where there is no liner, such as at pit-zips or shoulder vents.)   However, if your shell layer is saturated, even if the Gore-Tex is still breathing, the result may be the same.  Its no use having breathable layers if the outer layers prevent all breathing when they become saturated.

Not all breathable fabrics are made this way. Some are coatings applied to a base fabric. (The difference between a coating and a laminate is largely a difference in the construction process). Lowe Alpine and Unitika Industries manufacture a fabric called Triplepoint Ceramic which uses two coatings to achieve the breathability. The first layer is the micropourous water repelling layer, and the second is a water attracting non-porus layer. (The second layer is to the exterior of the garment.) A water repellant finish is then added on top.

After a good soaking, your breathable fabric does stop breathing to an extent. Tests showed that all fabrics lose an element of breathability. in wet conditions. The various configurations of Gore-Tex lost between 34 and 43% of their breathability, Helly-Tech's decline was just short of 75%, but Lowe Alpine's Triple Point Ceramic 1200, losing just 15% of its breathability. So don't believe the naysayers who tell you that your breathable jacket stops breathing in the slightest rain.

As far as I can tell, all breathable but water proof fabrics rely heavily on the water repellant outer finish to prevent the micropouous layers from getting plugged by water (as might happen in a heavy rain) or grease, dirt, and oils. You may be able to replenish this water repellant layer as it ages by using spray on commercial products such as Nikwax or "Scotchgard Water Repellent for Outdoor Fabrics". There have been raging debates on this subject on various bicycle mailing lists, but the key point to remember is that the fabric manufacturers themselves apply such a coating. Only spray the outside surface and don't rub or iron it in, the water repellency is needed only on the surface. (ICEBIKER is trying to get a direct answer out of 3M as to the suitability of this repellent on Gore-Tex, Activent, and other common fabrics.)

In addition to waterproof fabrics, there are Windproof Fabrics for use in outer shells. These maybe the heaver pack-cloth or Cordura type of fabric, or the newer micro-fleeces which incorporate a windproof layer.

The windproof micro-fleeces are some of the better fabircs for winter cycling (at below freezing temperatures) because they are highly breathable, very warm, and light. These garments often weigh less than half as much as a conventional winter garment and are less restrictive to movement. And, since they are highty breathable, much more so than any of the rain gear oriented fabrics, you will not get as clammy wearing them when working hard. These garments typically can serve as a mid layer or an outer layer and as such are very versitile.

Windstopper is the trademark of Gore for their microfleexe with a windproof layer. This fabric is used by Pearl Izume, The North Face and many others to make windproof garments.

These fabrics just arrived on the market in 96 and are not yet well known or proven, but several ICEBIKERS report good results with WindBlocker Fleece.

Breathability in Winter

None of the manufacturers are too specific about their claims of breathability in very cold weather. There is some speculation that water vapor dutifully vented through the micropourous layer will become trapped in that layer or the shell layer as it freezes upon contact with the cold. You may have seen evidence of this while ICEBIKING. You may notice a very find frost forming on your jacket. If you take off the jacket you can sometimes shake this frost off. For this reason, and for the fact that when it is that cold you don't need to worry about rain, many cyclists switch to some other outer layer when it gets really cold.

The windproof fleeces are designed for the cold, so presumably they will operate better in this environment than the water proof materials.

Other Fabric Pages:

Since there is no possibility of keeping up with all the subtle variations upon the rather few themes that exist in the outdoor fabric business today, we will include informative fabric links here.  Be advised that these are mostly commercial pages, so you will not get a totally unbiased opinion.

• Pearl Izumi Fabric Page
• Bicycling Apparel's Fabric Page