Castelli Aria Shell jacket review

Ultra-lean and lightweight, the Castelli Aria Shell is a proven contender for riding on windy days or in light rain in spring, autumn and chilly summer mornings.

Aided by mesh panels on the sides and a woven microfibre main body, the breathability sits at the top of the windshell jacket class.

The limited colourways (two greys and a brown) won’t suit everyone, but it’s a classy-looking and comfortable jacket that compresses easily into a jersey-pocket friendly bundle.

Water-resistance is limited, however – and you may well need to go up if you’re between sizes.

The Aria Shell jacket is priced at £135 / $140 / €125.

Castelli Aria Shell jacket specifications and details

The Castelli Aria Shell is constructed with a woven microfibre used on the front panels, the main back panel and on the front of the sleeves.

Complementing that are stretchy and striped mesh fabric inserts on the back of the sleeves and the side of the body to aid breathability and the fit of the jacket.

There’s an integrated pack sack in the lower-back area that enables the Aria Shell to be compressed into a tiny bundle that fits easily into a jersey pocket.

It can also act as an internal pocket when you’re riding.

There’s a full-length zipper guard for further deflecting chilly breezes from sneaking inside the jacket, while also minimising the chance of chafing from the YKK zipper head. That zipper is also easy to undo on the move.

The colourways are limited to Moss Brown (tested), Dark Grey and Silver Grey. No high-visibility option is available.

Castelli Aria Shell jacket performance

My key rides in the Aria Shell came in the hills north of Faro in Portugal during early spring.

Here, the woven build displayed its windproofing ability on the sweeping descents close to Barranco do Velho.

That windproofing didn’t come at the expense of breathability, however, with the sizeable mesh panels on the back of the sleeves and along the sides of the body ensuring my rides weren’t a sweat fest.

There are techier options around, but the elasticated bands on the arm cuffs helped prevent chilly wind intrusion and they sit comfortably alongside a sports watch.

The elasticated waist hem also keeps the jacket in place.

In anything other than light rain and brief showers, the water resistance was found wanting, especially around the sizeable mesh areas.

Admittedly, Castelli only bills the Aria Shell as a 2/5 on its arbitrary waterproofing scale, but some may want more anti-precipitation power from their wind jacket if they ride in rainy conditions often and don’t want a full-blown waterproof jacket.

Sizes are available from XS to 3XL and, as is typical from Castelli, it's somewhat on the smaller side, so size up if you’re between sizes.

The fit is comfortable, however, with the mesh panels providing plenty of stretch.

Because the jacket is available in only three colours, there’s no hi-vis option, although there is reflective Castelli branding on the rear.

The women’s-specific equivalent jacket comes in the same three colourways.

As you should expect with the top-end price tag, the finishing quality and on-bike comfort is impressive thanks to the tidy internal seams, a full-length zipper guard that prevents chafing and the neat integrated pack sack for jersey-pocket stashing.

As for pockets, there aren’t any on the outside of the Aria Shell, which isn’t unexpected on a lightweight wind jacket, but it means you’ll have to rely on your jersey pockets underneath for storing bars, gels and valuables.

The overall weight of my size-small jacket was a lithe 94g, which compares very favourably with the other windproof jackets I’ve tested this season.

Castelli Aria Shell bottom line

The Aria Shell won’t protect you from the worst and wettest weather, but it’s a breathable and lightweight performer for thwarting winds on chilly days in spring and autumn – and on summer mornings too.

The price is at the higher end of the windshell spectrum, but the quality construction befits a £100+ jacket, and it’ll also look good on your café stop ventures.