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Men's Free Aero Race 4 Bibshort

Mfg PartNum:
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Backorder: This item is currently out of stock but is available to purchase today as a backorder. The expected availability date shown above is our best estimate as to when it will be shipped to you, but this date is subject to change based on our receipt of this item from its vendor. Shipping in the continental US is free for all backorder items (for international orders, our customer service team will contact you when the item is available to ship). Your credit card will not be charged until your item ships (Paypal requires payment up front, but you can cancel for full refund). Anytime prior to shipment, your backorder can be cancelled by contacting our customer service team.

Pro Rider Approved — Castelli Free Aero Race 4 Bibs

The fourth iteration of the Castelli Free Aero Race bibs receive major upgrades for increased comfort, fit and durability.

The Castelli Men's Free Aero Race 4 Bibshort features a new leg gripper design with vertical silicone stripes to keep it in place without restricting stretch.

The seams have been updated to improve the fit and make this bibshort look even better on you, the rider. The bib straps have been re-engineered with new fabrics and construction to enhance airflow, durability, and smoothness against the body.

Impressively Soft and Seamless.

The revised Free 4 Aero Race Bibshort also receives the updated Progetto X2 Air seamless seat pad featuring the softest surface fabric you've ever felt in a seat pad.

You'll be glad Castelli ignored the old saying, If it ain't broke, don't fix it, because the Free Aero Race 4 offers pro status upgrades.


  • Vortex dimpled fabric on legs.
  • Forza fabric on inner legs with 38% Lycra® content.
  • Cooling stripe mesh engineered minimalist bib.
  • Giro4 leg gripper elastic for better grip distributed over larger area.
  • Supportive Doppio V construction in front.
  • Flat-lock stitching.
  • Progetto X2 Air Seamless seat pad.

  • Free Exchanges: This product qualifies for free exchanges within the first 60 days after order. We'll cover the shipping both ways for US customers if you need a different size and/or color of this product. Returned product must be in new condition with all labels and packaging. Free exchanges apply only for product in stock or available for backorder.


Style Type: Bibs 


Weight: 172 g


Fit: Race Fit 


Chamois: Progetto X2 Air Seamless 


Straps: Breathable mesh 

Black - Small

Mfg PartNum: L19003010-2 

Black - Medium

Mfg PartNum: L19003010-3 

Black - Large

Mfg PartNum: L19003010-4 

Black - X-Large

Mfg PartNum: L19003010-5 

Black - 2X-Large

Mfg PartNum: L19003010-6 

Black - 3X-Large

Mfg PartNum: L19003010-7 

Dark Steel Blue - Small

Mfg PartNum: L19003070-2 

Dark Steel Blue - Medium

Mfg PartNum: L19003070-3 

Dark Steel Blue - Large

Mfg PartNum: L19003070-4 

Dark Steel Blue - X-Large

Mfg PartNum: L19003070-5 

Dark Steel Blue - 2X-Large

Mfg PartNum: L19003070-6 

Dark Infinity Blue - Small

Mfg PartNum: L19003041-2 

Dark Infinity Blue - Medium

Mfg PartNum: L19003041-3 

Dark Infinity Blue - Large

Mfg PartNum: L19003041-4 

Dark Infinity Blue - X-Large

Mfg PartNum: L19003041-5 

Dark Infinity Blue - 2X-Large

Mfg PartNum: L19003041-6 

Dark Grey - Small

Mfg PartNum: L19003030-2 

Dark Grey - Medium

Mfg PartNum: L19003030-3 

Dark Grey - Large

Mfg PartNum: L19003030-4 

Dark Grey - X-Large

Mfg PartNum: L19003030-5 

Dark Grey - 2X-Large

Mfg PartNum: L19003030-6 

Ordered by Most Relevant First
5 stars
4 stars
3 stars
2 stars
1 stars
My new favorite bibs
by SaaSy Cyclist
Cycling Enthusiast
Portland, OR

These bibs are fantastic! Comfortable and supportive for training or racing

Reviewed 6/16/2020
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by KC
Seattle area

These shorts are very well made as well as extremely comfortable even for women.

Reviewed 5/21/2020
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Comfortable to wear & comfortable on the bike!!
by Mike Hutcheson

First time with the Progretto X2 seat pad - love it. Went with the compression version of these bibs & they are more work to get on, but after 50 miles of pedaling you can tell a difference.

Reviewed 8/26/2019
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Love 'em
by Anonymous
Cycling Enthusiast
San Diego, CA

Very comfortable and provide good cushion-light weight.

Reviewed 3/14/2020
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Nice fit, nice pad
by Anonymous
Cycling Enthusiast
1 of 1 customers found this review helpful.

The new pad is very nice, and I like it better than the previous Castelli pads. The fit up front is much better too. Straps are comfortable and work well. I'm 5'7 132 lb and have worn medium Castelli bibs in the past but this one is a small and fits perfectly. Snug, but that's my preference.

Reviewed 9/10/2019
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Best bib shorts
by Lamar

Castelli continues to improve on the bib shorts. Cant go wrong with these. Great for century rides.

Reviewed 9/5/2019
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Comfortable and light
by Anonymous

Can barely feel this chamois on my skin, and the chamois insert is comfortable. No numbness on long rides.

Reviewed 7/26/2019
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better leg gripper, better seat pad
by Anonymous
Cycling Enthusiast

It's an improvement on the old Free Race bib. I like the new seat pad. Still fits the same way.

Reviewed 7/19/2019
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Good idea, poor execution
by Anonymous

New bib strap fabric is very uncomfortable especially at the waist. Doesnt stretch and cuts into your sides when in an aero position. The seamless chamois moves around and ends up in the wrong place.

Reviewed 7/10/2019
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Leaves a bit to be desired
by MeesterE
Casual Cyclist
Portland, OR
1 of 1 customers found this review helpful.

I own a couple of Castelli pro bibs and shorts (Nano flex pro, the free aero race shorts and bibs) and would classify myself as more of a casual rider and in my experience using Castelli products, I have been nothing but impressed - not so much with these bib shorts. The fit is typical of Castelli, tight with good compression where it is needed - it's a comfortable fit with seams properly concealed or thoughtfully placed to reduce chafing. The straps, which are touted to enhance airflow, durability, and smoothness against the body are too narrow and end up twisting. The material is too thin and no matter how much I tried to keep them flat, they would bunch up and become uncomfortable on the shoulders - so much so that I mostly ride with the straps down. After my first ride - about 40 miles - I also noted there was pilling in the seat area from rubbing against my saddle - no holes, but still a bit disconcerting given the price I paid for the product. The chamois material and pad is comfortable but interestingly, the material doesn't completely cover pad - there is an area toward the back of the chamois, where you can see the pad and actually move it around. I initially thought the opening was there so you could take the pad out and case you wanted to wash or replace it, but it's sewn into the lycra. The pad still does what it's meant to do, but aesthetically, it's not nice to look at. With all that said, I still wear these mostly for my trainer sessions at home. They're comfortable and the dark steel blue color is a nice change from all the black shorts I have. Still a fan of Castelli, just not of this short.

Reviewed 6/8/2019
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A hole in the bib
by Anonymous
Cycling Enthusiast
Anaheim Hills, CA
0 of 2 customers found this review helpful.

I ordered 4 of these bibshorts but 1 of them had a little hole near the stitching on the front right leg.

Reviewed 5/20/2019
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Top of the line bibs
by Persico
1 of 1 customers found this review helpful.

Ive been wearing Castelli free Aero bibs for the past 5 years and every year they improve their shorts that much more.

Cant say enough about the Chamios for great comfort on the saddle and the leg grippers are very compressed and aero and feel like your wearing nothing at all. The only thing I would like to see Castelli improve on these are the shoulder straps. I would like to have a more wider strap that stays flat, these start out ok but seem to narrow around the chest.

Reviewed 4/30/2019
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