RoadTrailRide: Pactimo Cycling Kit Reviews: Powered by 37.5® - Temperature Regulating Technology

Article by Jeff Valliere

Pactimo Cycling Apparel

Have you ever heard of 37.5 ®?  Me neither, but I was recently invited to visit their HQ in Boulder for a tour of their facilities and an explanation of their technology, background and products.  

37.5 is a temperature regulating technology based on active particles permanently embedded in fabrics which attract moisture and move it away from the skin.

Along with 37.5, local Colorado cycling clothing company Pactimo was also presenting and were gracious enough to provide us with a cycling kit made from 37.5 treated fabrics which included:  Summit Aero Mesh Jersey,  Summit SL Base Layer, and Torrent Rain Jacket along with the Summit Raptor Bib Shorts. Subsequent to the event, I continued to test the Pactimo kit for this review.

How does 37.5 Technology work?

“37.5 Technology helps your body regulate temperature through the use of active particles permanently embedded within the materials. These particles attract moisture vapor and move it away from the skin. The more of these active particles present in a clothing system (baselayer, midlayer, outer layer) or bedding system (mattress/pad, sheets, blankets), the more efficiently they can move this humidity away from your skin. Simply put – the more products you use that are made with 37.5 Technology, the better it works.”

37.5’s Story:  

“37.5 Technology was created by a Ph.D. photo-physical chemist and inventor. In 1992, while in Japan on a JSPS postdoctoral fellowship, he was taken to the volcanic sand baths on Mt. Aso. At first, he thought he would only be able to stand the heat for a few minutes, but once buried in the sand, he found it surprisingly comfortable. So comfortable he stayed in the sand for an hour.

What he realized is comfort comes from balance, a balance between heat gain and heat loss. The volcanic sand was removing the sweat vapor from his skin so fast that he was continually cooled by sweat evaporation.

This was the moment of clarity, he understood that removing the sweat vapor before it turns to liquid sweat was key to comfort. While others were focused on wicking—spreading liquid sweat on fabric—he focused on reducing humidity next to skin to maximize evaporative cooling. And it turned out by enhancing comfort human performance was increased by reducing core temperature buildup. Now you can experience the same phenomena when wearing apparel and footwear made with 37.5 Technology.”

While the focus of this media event was on athletic clothing and Pactimo more specifically, they also make homewares such as bedding, mattresses and furnishings (think cool sleeping), as well as footwear and accessories that remove moisture and improve thermoregulation.  

The tour of the 37.5 temperature/humidity lab was impressive, where they walked us through the process of how they test the performance of the fabrics.  I will admit that I may have been a touch skeptical at first with such boastful claims of temperature regulation and evaporation, as I have heard these claims many times from other companies with varying degrees of validity. 

I will go through the specific pieces I tested below, but can verify ahead of time that 37.5’s claims are accurate, as I have found the performance of the cycling gear and running tops to be the best I have ever used to date.  

The fabrics are very soft and comfortable, are incredibly breathable and have the best evaporative quick drying ability that I have ever seen.  

As an added bonus, they do not accumulate odors over multiple uses.  I can easily get several days of use out of the jerseys, base layers and tees, though I limit the use of my bib shorts for obvious hygienic reasons.

Pactimo Summit Aero Mesh Jersey

Sizes S-3XL

$164

Featuring 37.5 Technology, with a lightweight, stretch mesh construction, the Summit Aero Mesh Jersey is a very lightweight, highly technical, modern jersey, packed full of features to keep you cool and comfortable on long rides.  It is available in a range of colors (white, blue, green, yellow and few other multi color options).

The Summit Aero Mesh Jersey also features:

• Euro Length Mesh Sleeves
• Semi Auto Locking Zipper
• 3 extra wide rear pockets with expanding bottom bellows and a zippered valuables pocket.

The materials are light, stretchy, breathable and comfortable.  I like that it is full zip, which makes it easier to put on and take off (especially when pockets are full and you need a bathroom break while wearing bib shorts) and the full zip is great on hot days and long climbs to unzip and catch some extra venting.

The sleeves are long and go nearly to my elbow, which I really like as the sleeves provide extra sun protection without feeling warm while remaining comfortable.

The neckline is very streamlined and comfortable, as is the waist hem, which also has rubber grippers on the inside to keep the jersey in place.

The pockets are the traditional 3 pocket design with an additional zippered pocket overlaying the right pocket which is perfect for a wallet, car key or any smaller valuables you don’t want in the mix with food, wind shell or phone.  The pockets are slightly wider than normal and have a baffle at the bottom for a little added expansion when stuffing in a jacket or multiple items.

Fit: is described to me as “Italian” or high performance race fit and it was recommended to me to size up, and that was a good call.  I have essentially been the same size/height/weight since 1991 and have always worn size medium, but went with a large here and the fit is just right.  Any tighter, I would feel self conscious and any looser would I would feel recreational.  

The arms sleeves are the perfect (long) length and reach almost to my elbow.  I have thin arms and there is a slight bit of extra room, but it would not take a much larger circumference are to fill out the sleeve and has plenty of stretch to accommodate if you have average size arms.

Performance/Conclusions:

The Summit Aero Mesh Jersey is one of the most high performing jerseys that I have ever worn.  It is exceptionally comfortable, breathable, quick drying and odor resistant.  On warm days (in the 80’s and even 90’s) I feel quite cool and appreciate the extra sun protection of the longer sleeves, as well as the full zipper which helps to provide maximum ventilation.  The odor resistance is remarkable, as long as I hang it to air out after a ride, it dries quickly and I can easily get several rides out of it before I feel the need to wash.

Pactimo Summit Raptor Bib Shorts

Sizes S-2XL

$229

Made for long distance rides and engineered to offer a compressive fit with Raptor fabric featuring Flash coldblock® to keep you cool and dry for muscle soothing comfort.  The Road performance Force Chamois is intended to be suitable for 7+ hour rides.

Features

The multi-density, multi-layered foam construction is anatomically designed for maximum comfort and support on long-distance rides.  The bib straps are made of a wide, but thin mesh material that has some stretch, but are very secure and hold the bibs in place with no pressure points, chafing or rubbing on bare skin.

Fit:  

Fit is in line with the Summit Aero Mesh Jersey, “Italian fit”, where I also needed to size up to a large.  In doing so, they feel just right in all areas, from leg cuff snugness, leg length, torso, butt, bib straps to the critical fit in the nether regions where the shorts are not overly snug or uncomfortable, just enough room to not constantly have to be adjusted or feeling overly confined.

Performance/Conclusions:

Overall I found performance of the Summit Rapto Bib Shorts to be top notch and I cannot find a single complaint or nitpick.  They fit so very well (provided you size up), have a stylish look and are quite breathable, quick drying, and have secure and comfortable leg grippers  with the seams are comfortable.  

They are exceptionally well padded, yet do not feel overly bulky and feel as though I can ride in them all day without my butt hurting or my private parts going numb (of course saddle choice is critical here as well).

Summit SL Base Layer

Sizes XS-3XL

$75

I have been slow to adapt to the baselayer idea for cycling, but am glad I did!  The Summit SL Baselayer fits perfectly when sizing up to a size L from my normal medium and when combined with the Summit Aero Jersey is a very cool and well vented combination.  It is light, thin, breathable and quick drying with no odor retention.  I easily get several days out of it before I consider washing and even then, not because I have to, but because I am doing laundry anyways!

Torrent Rain Jacket

Sizes S-3XL

$225

The Torrent Rain Jacket is 100% waterproof with taped seams and a waterproof zipper.  

It also features 37.5 active cooling technology to keep you cool and dry. The 37.5 technology and knit fabric help move heat and moisture away from the body to ensure a dry, heat regulated interior over long distances.

The Torrent has a very long tail to keep the road spray off of your backside.  The cuffs are also extended for a bit of added coverage.

The seams are taped and have a waterproof zipper that adds to the waterproofing.  The zipper is 2 way, which is great having the option to zip from the bottom up depending on conditions and preferences.

While the Torrent jacket feels and performs like a sturdy rain shell, it packs surprisingly compact and easily fits into a jersey pocket.

There are two mesh stuff pockets on the back, plus a zippered drop pocket on the side for valuables.

The hem is nice and grippy to prevent ride up.

Fit:

Again, even though I have been a medium (or small even) in just about every shirt or jacket my entire adult life, I sized up to large yet agai here and that was the right choice.  Fit in the arms, torso and overall length is perfect and can easily fit over a cycling jersey or two, conforming perfectly for a quiet, no flap ride without feeling constraining in the least, as it has a bit of stretch.

Performance/Conclusions:

The Torrent lives up to its claims and is a premium and essential piece of gear to pack along for a ride where you may encounter rain and wet. As we are subject to afternoon storms here in Colorado, I have brought it along on several rides where I figured there was a good chance of rain and was glad I did, as I got stuck in one good deluge and was thankful for the waterproof, breathable comfort of the Torrent.  It shed the rain off and I stayed dry inside without feeling clammy.  Once the rain stopped and the sun came back out, the Torrent dried quickly.  With its high performance, streamlined fit and packability, I highly recommend it!

Pactimo Cycling Apparel is available HERE

Jeff Valliere has been around bikes his entire life, as a toddler following his dad to bike races and bike shops, BMX racing as a kid, working in bike shops as a mechanic for 14+ years (10 at U-Bikes in Boulder where he met John) and racing as a professional road cyclist for several years.  Jeff no longer races, but still loves to ride as he introduces his daughters to the joys of cycling.  In addition to being obsessed with cycling, he runs mountains daily and has been reviewing running shoes/gear/tech for RoadTrailRun since 2015 and for other publications/companies since 2005.

Samples were provided at no charge for review purposes. RoadTrail Run has affiliate partnerships and may earn commission on products purchased via shopping links in this article. These partnerships do not influence our editorial content. The opinions herein are entirely the authors'.

Comments and Questions Welcome Below!