Gerbing Heated Jacket Liner review
Nov. 2005

It's hard to deny that the Gerbing Heated Jacket Liner has become a favorite defense against the challenges imposed by cold weather riding.

It is so well regarded that it has almost achieved cult status among its owners.

Could it really be this good?

Description:

• Heated Jacket Liner using Gerbing's High Density Heat^tm technology
• Heat Panels/pads on the chest, back, collar, and sleeves.
• Compressible, Thinsulate® insulation.
• Teflon® coated, wind and water resistant, soft nylon shell.
• Hand warmer pockets.
• Deep, inside chest pocket
• Form-fitting cut
• Zipper-enclosed Glove plug pockets on sleeves
• Lifetime warranty on heating elements
• 77 watts $199US
  
  

Overview:

Past variations of the Gerbing Heated Jacket Liner have included a lightweight, non-insulated shell version as well as a heavier, insulated quilted version.

In this most recent iteration, the Gerbing Heated Jacket Liner comes to market with a windproof, water repellent outer shell and Thinsulate® compressible insulation. As always, the collar is heated. In addition, the sleeves now house a zippered compartment to stow connectors for plugging in heated gloves.

What I found:

Wearing the Gerbing heated jacket liner while riding in typical late season temperatures often hovering around 0C (32F) is a revelation. It produces high levels of evenly-distributed heat. What's more, this heat is very comfortable and soothing. The heated collar, lined with a soft, velvety material, seals well against the cold and warms evenly around. Similarly, the heated sleeves surround the arms in warmth. But aside from producing good heat, it is very effective as a standalone insulated windbreaker, adding to its versatility. Those are the basics.

In putting the jacket liner through its paces, I found myself re-thinking what I had for a long time considered to be unassailable conventional wisdom. The theory here is that heated clothing is best worn very close to the skin. This direct contact with the heating elements allows a more effective heat transfer. But my experience wearing the Gerbing Liner showed that this was not the only way nor was it necessarily the best way.

Though contact heat may be quicker and more efficient, radiated heat feels better, more luxurious.

So what makes it tick?

Understanding how the Gerbing liner produces this high quality of heat helps in explaining why it’s so effective.

__There are several parts that play a key role:

• Teflon-coated windproof shell and Thinsulate® lining

How much heat a garment produces is one thing. But how it manages that heat makes a big difference. On the outside, the windproof shell and Thinsulate® lining work effectively to seal out the cold. On the inside, they retain heat and cut down radiated heat loss to environment, even when not plugged in. As such, the liner serves as an effective internal wind barrier. This allows it to work well under a summer-weight or mesh jacket. In addition, the shell is water repellent, further helping cut down on cooling.

The liner also works well enough on its own that it can be worn as a windbreaker on a cool night at the campground.

• Effectiveness of heating pads

Instead of sewing heating wire in their garments, Gerbing uses what they refer to as Hi-Density Heat Panels.

We can think of these panels as heating pads that are sewn into the garments in various locations. Each panel, or pad, contains a high density of heating wire that is evenly distributed. This results in uniform heating over the full surface of the panel.

That’s the theory behind it. All I can say is that they work: Place your hand anywhere inside the jacket liner where the heat pads are inserted and feel uniform, comforting heat. There are no cold spots resulting from widely spaced heating wires as is the case in some lower-powered vests. In addition, your arms will enjoy surrounding warmth.

There is another practical benefit. The use of Heat Panels along with Gerbing's parallel wiring system means that, if one Panel should fail, the rest of the Panels in the Liner would continue to produce heat. A failure on a heated garment using a conventional wiring system would result in total heat loss. That could be a significant advantage during an extended ride on a cold, dark night.

• Blouson-type of cut allowing some trapped air for radiated heat

Of course, the Gerbing jacket liner puts out more than enough heat to efficiently transfer warmth by direct contact with the heating elements.

But it also radiates sufficient heat to warm up the internal air space allowed by the slim, blouson-type fit of the liner.

Once zipped up, the windproof shell and Thinsulate® combine to provide an enclosed and protected cocoon of airspace. Warmed up, this results in a very comfortable inner environment.

I find this slightly looser type of fit to be a key benefit when compared with a typical heated vest that tends to fit more snuggly. It provides an advantage in two ways.

• First, it’s a much nicer feeling. It's true that I've always considered a snug fit as the desired way to wear heated clothing. But this was more a choice of necessity rather than of preference. This is especially so with a lower wattage heated vest. But truth be told, the feeling of hot in contact with your skin is not always the most comfortable. At full power, our skin can only absorb so much heat before we feel some discomfort.

• But secondly, the warmed air inside the liner increases the effectiveness of heat absorption. It allows our skin to absorb warmth over a surface area greater than that limited to heating elements.

At least, that’s what it felt like to me when testing at temperatures hovering on either side of 0C (32F).

To determine exactly what was going on, I set up a standardized test and took some temperature readings. I was not concerned about temperatures achieved by the heating elements. Rather, I was interested in seeing how much heat was radiated by the liner to warm up the internal air space.

This involved suspending the jacket liner on a hanger and sealing off the wrists and neck openings. I then suspended a heat probe at about sternum level and at about the same distance from the front and back of the liner. I was looking to measure how warm the internal air space would become from the radiated heat. No contact with elements allowed.

What I found was revealing but not surprising.

• With the electronic temperature controller set at 25% of max power output and a reading taken at 15 minutes from cool-down, the temperature probe indicated 38C (100.4F).

• With the electronic temperature controller set at 50% of max power output and a reading taken at 15 minutes from cool-down, the temperature probe indicated 39C (102.2F).

• With the electronic temperature controller set at 100% of power output and a reading taken at 15 minutes from cool-down, the temperature probe indicated 47C (116.6F).

These readings confirm the Gerbing liner’s ability to produce sufficient heat to not only warm by direct contact, but also by providing a warm inner atmosphere. They are consistent with the way that the jacket liner felt to me while cold-weather testing.

In order for our body to absorb heat from our environment, ambient temperature needs to be higher than our core temperature of approx. 37C (98.6F). The above readings indicate that at a setting of 25% power, we would be absorbing heat, even without benefit of direct contact. Of course, this implies wearing an insulating layer over the jacket liner ie a cold weather riding jacket, so as to minimize externally radiated heat loss. With a lighter external jacket, the heat setting would understandably need to be higher. But the findings are revealing and help explain why the liner feels good.

This also means that if I can keep an ambient temperature of over 44C (112F) within the liner, there is less need for me to rely on strong contact heating.

This doesn’t mean that a heated liner should be worn with a loose fit. Not in the least. The larger the internal free space, the longer to heat it up and the lower the ultimate air temperature achieved. Fit should still be trim and snug. But I found the normal looseness afforded by the Gerbing jacket liner to be a factor in providing an enhanced level of heated gear comfort.

Hook-up options:

Hook up is a simple affair. The new Gerbing plugs function well and seem quite durable. You can either connect using a basic on-off switch or with the digital temperature controller. The temp. controller allows you to dial in the power output required according to your needs. I highly recommend it. For most cold weather riding, I will initially warm the liner up at full power. This quickly gets things up to temperature allowing me to later scale back for maintenance. Should I wish to plug Gerbing heated gloves directly to the liner, I simply unzip the small pockets containing the hide-away connectors. These are located on the forearm, near the wrist.

Versatility:

Appearance-wise, the Gerbing Liner looks fine as a black nylon windbreaker. It is decent enough to be worn by itself, off the bike, adding to its usefulness.

Another example is wearing it around a camping rally site at the end of the day when temperatures gets cooler. For such occasions, the two shallow-angle handwarmer pockets will come in handy.

Likewise, taking off your riding jacket in a restaurant will not make you feel out of place.

Back on the road, the Gerbing Liner will provide plenty of soothing and well-distributed heat, allowing you to handle whatever weather comes your way.

Overall:

There’s something to be said about the convenience of just slipping the liner on and knowing that you’re ready to go and take on the cold. Simple. Effective.

Over the years, the Gerbing heated jacket liner has earned a strong reputation for its ability to keep a rider warm in cold weather. I can only say that it’s reputation is fully justified.