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Castelli Free AR 4.1 Jersey - Men's

Sale $79.97 $159.95 50% off

Item # CST00B1

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Item # CST00B1

A speedy favorite.

With a professional pedigree and a predecessor designed to win the Giro, the men's Free AR 4.1 Full Zip Jersey had a lot to live up to when Castelli began updating it for 2016. While last year's version was focused on pure functionality in favor of embellishments, the designers at Castelli managed to weave in a few extras on the 4.1 to enhance its versatility for everyday riding. Most importantly, the claimed savings of 12 watts at 40kmh that the Free AR has been known for is back again, and with it, the streamlined, aerodynamic fit that you'll want whether you're planning a breakaway in your next road race or pulling during a coffee shop loop with your riding group.

In contrast to some of its pro-inspired apparel, Castelli paid attention to achieving a slightly more versatile fit with the Free AR 4.1. The fit starts with Velocity fabric, a lightweight, dimpled synthetic that increases airflow over the body to improve aerodynamics. Velocity is also designed to have ample stretch, which is what gives the Free AR 4.1 its more accommodating fit across a broader range of body types. Don't get us wrong, the Free AR 4.1 still has the tighter chest and shorter body that characterize Castelli apparel, but it doesn't require you to have a GC body type to be comfortable in the saddle.

Nervato fabric panels along the underside of the sleeves serve to improve airflow as well, while mesh raw-edge arm grippers lie flat and stay in place with as little drag as possible. We see this year's new features like a zippered rear pocket and neck-protecting flap at the top of the full-length zipper as welcome additions to this already well-loved jersey.

  • Velocity dimpled fabric
  • Raw-edge mesh arm grippers
  • Neck-protecting zipper flap
  • 1 zippered, 3 rear pockets

Tech Specs

[front & shoulders] Velocity, [armholes] Nervato
aero race
1 zippered rear, 3 rear
Recommended Use:
road cycling
Manufacturer Warranty:
1 year

Size chart


Men's Apparel
Chest 36.2in
Waist 31.5in
Hip 37in
Inseam 31.9in
How to Measure:
For best results, take measurements over your underwear.
Measure under your arms, around the fullest part of your chest.
Measure around your natural waistline, keeping the tape a bit loose.
Measure around the fullest part of your body at the top of your legs.
Using pants that fit well, measure the crotch seam to the bottom of the leg.

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Avg. ride time: 1h 34m per week
  • Average ride time is based on Strava activity over the last 3 months. Give your reviews credibility by connecting your account.

Go-to jersey.

  • Familiarity: I've put it through the wringer
  • Fit: Runs small
  • Size Bought: XL

Just like the free aero shorts, this is my workhorse jersey for everyday rides after trying them on. And just like the shorts, they beat Pearl Izumi in every way. The fit forms to your body instead of a club fit, the white doesn't fade or retain stains, and the pockets are bigger.

Did I mention that it just looks good? The asymmetrical collar is a bit hard to get used to (one side is shorter near the zip to show the red flap), but everywhere else it looks great.

For those who want a looser fit, however, look elsewhere. This is made for aerodynamics so there's no flapping material. And yet the material is so stretchy that it doesn't feel like you're a stuffed sausage.

As with their shorts, a Pearl Izumi large sizes into a Castelli XL.

Avg. ride time: 6h 8m per week
  • Average ride time is based on Strava activity over the last 3 months. Give your reviews credibility by connecting your account.

Great Fit

  • Familiarity: I've used it once or twice and have initial impressions
  • Fit: True to size
  • Size Bought: Medium

First time buying some castelli kit, those italians sure know how to make something special!, I love the kit. I try to wear it just for special ocassions

Great Fit

Castelli and the Three Bears

  • Familiarity: I've put it through the wringer
  • Fit: True to size
  • Size Bought: Small

I'm relatively new to Castelli after many years of Pearl Izumi. I'm 65 years old, short and skinny, so a trim fitting kit is desirable and hard to find.

The Three Bears story unfolded this way:
First Bear: purchased the Velocissimo and while it fit fine in the chest and shoulders, it was saggy/baggy in the lower torso, loose in the sleeves, and flappy in the wind.
Second Bear: tried the Prologo 3 with "slim" fit and it was a bit better fit in the lower torso, the sleeves were loose and overall too loose.
Third Bear: out of the box, the Aero Race fit was a little too tight. But after several rides it relaxed and now fits like a second skin. Just right.

Well-designed patterning is important but programming the 4.1 with several fabrics, each with a separate functional intent, is equally if not more important. The materials used along the front, sides, back and pockets are very light and porous (hold one of these jerseys up to a back light and you'll know what I mean) yet the structure of the fabric is differentiated (outer face vs. inner face) to deflect, absorb and transport heat, cold and moisture. Raw edges and/or siliconized cuffs transition these areas into smooth, flat-laying surfaces to the skin. Modern cycling apparel from Castelli (and others) just work and fit better in a wider range of conditions than apparel fabricated of non-differentiated patterns and materials.

So, I'll follow the example of the Three Bears and stick with Rosso Corsa Aero Fit kit.

Castelli Aero

  • Fit: Runs small
  • Size Bought: Large

I ride between 100 and 200 miles a week year round. The Castelli provides a great fit and is very aerodynamic. Everything a what-to-be would wish for, except for a quiet motor!