Castelli Insolito Radiation Jacket


In the hype of a press release, Castelli touts its latest three-season cycling jacket as a “breakthrough technology that ushers in a new era of comfort and performance.” With a stretchy, fluorescent-yellow face fabric, zip-off sleeves, vents, and a liner of metalized polyester, the $499 Insolito Radiation jacket does indeed stand out as something new.

Extreme adaptability to outside temperatures during the autumn, winter and spring cycling seasons is the Insolito’s primary claim to fame. With a modular design, wearers can pull on a hood, open vents, add a liner, or zip off sleeves to create a vest. These regulating attributes result in a piece the company cites as having a comfort range for cyclists from 25 to 65 degrees Fahrenheit.


The shell

The modular nature of this piece is nothing new. Outerwear makers have long sold ski jackets and other pieces with removable components to regulate heat. But what makes the Castelli concept unique is a fabric technology in the liner that uses a thin reflective material akin to Mylar and other similar metalized “space blanket” materials. Called Radiation fabric, this silvery sheen helps maintain body heat without relying on a bulky insulation like fleece.

I got a press sample of the Insolito in August and rode with it during a couple cool September nights. This was not the optimal — nor intended — time of year for the piece, but even so I could feel the Radiation fabric doing its thing. Like a space blanket, the liner reflected and retained body heat that would otherwise ostensibly be escaping into the ether. (Castelli purports that 80 percent of the body’s heat is reflected back with the aluminum-based liner.)

To keep the jacket breathable, Castelli ( perforates the metalized film and laminates it to a woven substrate. The final product, in the test size large, is a crinkly wisp that weighs 3.9 ounces on my scale.

The jacket’s outer shell is made with Gore’s Windstopper X-Lite fabric to shield from cold blasts seeping through the fabric face. Though it’s not made for rainy rides, the water-resistant Insolito will protect against snow, sleet, ice and other wintery elements that might fall from the sky.


The liner

Overall, the Insolito got my attention for its new approach to heat regulation. My tests this winter, riding through the Minnesota snow in temps well under freezing, will result in a final verdict.

The jacket, which comes in red and the highway-worker yellow, is a high-quality piece, well-fitting and with all its pockets, zippers and vents in the right places. The cut is long at the back, short at the front, with jersey pockets all around. Its stretchy, fleecy hood is tight and warm, and it fits under a helmet without issue.

The Radiation liner zips in and out from the Windstopper shell. You add it to the setup on the coldest days. Small snaps secure the Radiation liner’s sleeves and hold the top in place.

At its retail price of $499, the Insolito Radiation jacket and its cousin, the women’s Alamos, do not have mass market appeal. But for the cyclist who wants an all-in-one system — or something with the utmost in versatility — this shell with a silvery sheen inside could be a perfect fit for the cold-weather pelaton.

(Stephen Regenold writes The Gear Junkie column for eleven U.S. newspapers; see for video gear reviews, a daily blog, and an archive of Regenold’s work.)

Posted by Sandy - 12/19/2009 01:20 PM

I am interested to know the final verdict. from your tests during the winter, riding through the Minnesota snow in temps well under freezing.

Posted by Stephen Regenold - 12/21/2009 11:42 AM

It’s a great piece. At $499, you have to be pretty serious to buy one. It is warm/usable down to 10 degrees or even less if you layer right.

Posted by Dwayne - 03/24/2010 10:04 PM

I know this is late in posting but I live in Minnesota and have had mine since August 2009. I have worn it throughout the winter while commuting back and forth to work 20 miles/day down to -15° F plus wind-chill. This jacket out preformed well beyond my expectations. Most of the time warring a Craft Cool Mesh Sleeveless Base Layer, Icebreaker Sport 320 long sleeve merino top or a Craft Pro ZERO Zip Mock Neck long sleeve shirt. These worked extremely well through the coldest winter, 15° F to -15° F. Above 15° F I layered differently. This has been a great fall and winter jacket even in an extreme downpour during my whole ride to work. I stayed dry. I’m 5’-8” tall 152 lbs 39” chest. Large jacket. $325 Backcountry

Posted by Paul - 11/17/2010 09:35 PM

Dwayne: Any recc on tyres (carbon tip)? I like the icebreaker lines and have several types; some with hoods and figured that you don’t really need another coat with a hood if it does not cover the helmet. In essence, does the hood work well or not? And are there are other jackets that give wind protection, etc. such as ENDURA jackets STEALTH or MT that could also be used?

Posted by Dwayne - 02/03/2011 01:47 PM

Paul. I apologize for not getting back to you sooner. I will admit I don’t check this site frequently. As to the hood on the Insolito Radiation jacket works like it is designed. It is very effective. I only use it when the temperature is very low with even lower wind-chill temps. I have a Rapha Winter Hat that I wear all winter long. Very warm. If I need the hood it goes on under the Rapha. In early to late fall I wear a Chrome Cobra jacket. Works very well at temperature control (100% merion wool) and in light to moderate rain I use a Castrelli Fusion jacket. Pretty good at keeping me dry and has great ventilation. (2 large zippered vents in the back). Very good at keeping the cool wind off of me. If it looks like it is going to be a hard rain I wear my Castrelli Insolito Radiation jacket without the radiation jacket. For some reason I don’t usually wear the Castrelli Insolito Radiation jacket with the sleeves zipped off. As you might have noticed I like good ventilation. In my book it is well work the extra money.
As for winter tires go. I’m in my second year with Schwalbe Marathon Winter studded tires 700×38. They work great. I have (knock on wood) never fallen with them on my bike. Some complain they are noisy but the low rumble does not bother me. They are still in good shape. I should get a total of at least 3 years and maybe 4 years of use out of them.

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