Often times, the hardest part of riding is just getting out of your front door. This is especially true on days when cold and dreary weather makes you wonder why a sane person would leave the warmth and comfort of your home. PEARL iZUMi developed the PRO AmFIB Cycling Jacket for these types of shoulder season days. The “AmFIB” refers to the 4-way stretch fabric which is both windproof and water-resistant while being a claimed 50% more breathable than typical membranes. In this review, we’ll look at the Men’s Medium size shell in Atomic Red. PEARL iZUMi also offers a Women’s version of the same jacket.

The PRO AmFIB shell features an alphabet soup of PEARL iZUMi features (PI Dry water shedding technology, BioViz reflective elements and Vislon Aquaguard zipper). PEARL iZUMi incorporated a number of thoughtful details in the construction of the PRO AmFIB shell a couple of which are: a high neck, bonded seams, reflective elements on front/rear, three pockets (with the center pocket zippered) and a dual front zipper. These features combine to make the AmFIB shell a very stretchable and comfortable shell in both cold and warmer climates. In particular, we were very impressed with the breathability and fit of the jacket especially compared to lower quality windbreakers.

CategoryBicycle Clothing
RatingDesign: A
Sizing: A-
Warmth: B+
Retail Price$225
Likes+ Minimal yet Modern Design
+ Bright ‘atomic red’ Color
+ Attention to detail
Dislikes– Lack of warmth for colder temperatures
– Zippered center back pocket
Where to Buy (US)PEARL iZUMi

The PEARL iZUMi PRO AmFIB Shell is an extremely comfortable and versatile shell for shoulder season riding.


It was nice to see the environmentally conscious packaging as this jacket came in a 100% recycled plastic bag which in turn was in a generic brown shipping box.

Pro AmFIB Shell bag


One of our favorite things about the PRO AmFIB shell is the clean and simple design. Rather than plastering it with graphics and logo to make it look sporty, PEARL iZUMi has gone with a more subtle and timeless design. In terms of logo, the PEARL iZUMi text logo can be found embossed on the chest of the shell as well as the reflective strip under the rear center pocket. Otherwise, the shell is a solid color with only the seams and functional details to break it up. 

PRO AmFIB Cycling Jacket Backside
Backside with 3 pockets and Split Yoke on the Shoulder

The atomic red color looks more red on the PEARL iZUMi website, while in-person it looks more like a neon red or deep coral color. This is one of our favorite shell colors to-date as it’s great for visibility and a welcome change from the typical all black gear many cyclists wear. However, the shell is also available in teal and black for a more subtle look.

PRO AMFib Cycling Jacket - backside grippy strip
Grippy strip on the inside of the backside


This jacket is available in Small to XXL. We tested a medium sized men’s PRO AmFIB shell and found the sizing to not quite match the PEARL iZUMi website sizing chart. Based on the measurements of a 160lbs and 6’ 1” male, the chart recommended a size “Small” while a quick test fit at a local bike shop indicated a Medium size was a better fit. Additionally, this shell is “form fitting” which means it is designed to fit the body snugly and stretch around your features. We’d recommend trying it or a similar PEARL iZUMi shell in-person for sizing before buying.

PRO AmFIB Cycling Jacket Side view
Side View

Despite the sizing confusion, the Medium sized AmFIB shell fit very well without being restrictive even during out of saddle positions or while riding the drops. Compared to loosely fitting shells which flap in the wind during higher speed descends, the AmFIB was comfortable and silent. Also, the thoughtful construction of the AmFIB meant there was no clumping or bulging at any of the seams or joints. The bonded (glued) seams reduce the bulk compared to sewn joints and hem, this also results in a very stretchable shell.  

Also the shoulder of the shell features a split yoke design with a single piece of fabric running from the center seam all the way down the length of the sleeve on each side. This provides a better fit by allowing the fabric to stretch more comfortably across the shoulders and allows for articulation of the sleeves.


During out testing, we wore the PEARL iZUMi AmFIB shell during some chilly morning rides (mid-30°F) as well as some warmer days (mid-60°F). Despite  being in Northern California which doesn’t have what most people would consider proper seasons, we consider this our shoulder season where early mornings start out uncomfortably cold before warming up to moderate temperatures. While the clothing tag or the website doesn’t specify the temperature rating, we found this shell to perform best between 45°F-65°F degree temperatures. Due to its breathability and dual zipper design it is easy to prevent overheating during high-intensity climbs and stay warm during cold descends.

PRO AmFib Cycling Jacket cuffs
2-way zipper, reflective detail, and protective sleeve cuff

With the number of layers we wore (a baselayer + long sleeve jersey) we found that the AmFIB shell let in wind chill under 45°F.  Possibly with thicker baselayers, the AmFIB could be used in colder temperatures but note that this shell isn’t as thick as a typical bulky winter jacket. Also, we would like to point out that we are particularly impressed with the breathability of the fabric. The shell has excellent thermal management, which makes it a very versatile shell to own.

This shell also has a proprietary PI Dry coating which causes water to bead up and slide down instead of absorbing into the fabric during light sprinkling of rain.

PI Dry Water beading
PI Dry Water beading


Although the AmFIB shell comes with a premium price tag, we found it to be excellent value as the features and attention to details justified the price. The excellent fit, breathability and functional details like the two-way zipper make the AmFIB shell something you can easily wear throughout the year. Unlike traditional plastic-ky feeling windbreakers, the PRO AmFIB shell is soft and stretchable while still being windproof and water resistance. Its extremely comfortable and lets your forget about the weather and focus on riding instead. Also, PEARL iZUMi stands behind their products with a lifetime warranty and excellent customer support which ensure the PRO AmFIB shell is a piece of cycling clothing you can rely on for years to come.

Disclaimer: The product for this review was provided by PEARL iZUMi. The views expressed on this website are solely those of the authors and are here to help people make an informed choice before a purchase. The authors or the blog itself does not get any monetary compensation from the product manufacturer or third-party websites/vendor links that are posted here.

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