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Castelli Mens Free Aero Race 4 Bibshort Kit Version
Castelli Mens Free Aero Race 4 Bibshort Kit Version

Castelli Men's Free Aero Race 4 Bibshort Kit Version

Mfg PartNum:
In Stock Now
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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.

Meticulous Evolution

The new Free Aero Race 4 Bibshort is the result of over a decade of partnerships with pro teams. Castelli has implemented miles of racing and riding experience into ensuring that the latest clothing is ready to meet the demands of professionals, and also that of performance-focused cyclists. As one of Castelli's best-selling bibshort for the professional rider and race-ready athlete alike, the latest iteration keeps everything loved about the Free Aero Bibshort and makes a few key improvements.

Minimal and Fast

A brand new bib construction is implemented for a minimalist fit, which has been combined with fabrics that boast better breathability. Featherweight, super-thin striped mesh aids in breathability. When the race turns up, the Free Aero Race 4 will lend to better temperature regulation than before.

New leg grippers lay flat, allowing stretch through all phases of the pedal stroke. Now with vertical silicone, the laser cut raw edges are staying right where they belong, from the beginning to the end of your ride. Receiving the updated Progetto X² Seamless seat insert reduces road vibrations while be extremely soft and comfortable.


  • Freshly updated - Castelli's most popular bib short
  • Vortex dimpled fabric on legs for aero performance
  • Forza fabric on inner legs with 38% Lycra® content for perfect fit
  • Stripe mesh engineered minimalist bib construction keeps you cool
  • Giro4 leg gripper elastic for better grip distributed over larger area
  • Doppio V construction in front for increased support and comfort
  • Flat-lock stitching reduces irritation
  • Progetto X2 Air Seamless seat insert cushions against road chatter
  • 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.

    B-Stock - This product has one or more B-Stock units available. These units can be purchased at a discount (see option select). B-Stock units were returned from other customers and may have missing or damaged packaging materials. These units are otherwise as new. The full manufacturer warranty applies. Click Here for more information.

    The product weight specified is an approximate weight based on the manufacturer's specifications (if available) or our measurement of one or two examples. For most products, the weight will typically vary by 5% to 10%.


    Fabric: Forza 

    Weight: 172 g

    Temperature Range: 59°-95°F 

    Chamois: Progetto X2 Air Seamless seat pad 

    Discipline: Road Racing 

    Style Type: Bibs 

    Black/Black - Small

    Mfg PartNum: L20003010-2 

    Black/Black - Medium

    Mfg PartNum: L20003010-3 

    Black/Black - Large

    Mfg PartNum: L20003010-4 

    Black/Black - X-Large

    Mfg PartNum: L20003010-5 

    Black/Black - 2X-Large

    Mfg PartNum: L20003010-6 

    Black/Red - Small

    Mfg PartNum: L20003023-2 

    Black/Red - Medium

    Mfg PartNum: L20003023-3 

    Black/Red - Large

    Mfg PartNum: L20003023-4 

    Black/Red - X-Large

    Mfg PartNum: L20003023-5 

    Black/Red - 2X-Large

    Mfg PartNum: L20003023-6 

    Dark Gray/Dark Gray - Small

    Mfg PartNum: L20003030-2 

    Dark Gray/Dark Gray - Medium

    Mfg PartNum: L20003030-3 

    Dark Gray/Dark Gray - Large

    Mfg PartNum: L20003030-4 

    Dark Gray/Dark Gray - X-Large

    Mfg PartNum: L20003030-5 

    Dark Gray/Dark Gray - 2X-Large

    Mfg PartNum: L20003030-6 

    Savile Blue - Small

    Mfg PartNum: L20003414-2 

    Savile Blue - Medium

    Mfg PartNum: L20003414-3 

    Savile Blue - Large

    Mfg PartNum: L20003414-4 

    Savile Blue - X-Large

    Mfg PartNum: L20003414-5 

    Savile Blue - 2X-Large

    Mfg PartNum: L20003414-6 

    Ordered by Most Relevant First
    5 stars
    4 stars
    3 stars
    2 stars
    1 stars
    Reviewed 10/30/2020
    by SFRonH
    Cycling Enthusiast
    San Francisco, CA
    Value Rating
    Overall Rating
    Good quality nice bib shorts

    These bib shorts are consistent with other Castelli bib shorts. This model tends to fit a bit tight, in a good way. The color was advertised as blue, but the product is actually gray. It's an attractive short. Castelli tweaks the designs often--about every year?--so this is another tweak, and perfectly good.

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    Thank you for your feedback.
    Reviewed 10/26/2020
    by Anonymous
    Sebring FL
    Overall Rating
    Best IMHO

    After years of resisting bibs because there's no ez way to relieve yourself I tried these. Outstanding fit, finish, feel, and ease of relief! Love these bibs and all Castelli products. I ride about 150 miles a week with regular centuries.

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    Thank you for your feedback.
    Reviewed 8/16/2020
    by Anonymous
    Cycling Enthusiast
    Value Rating
    Overall Rating
    Top level bibs

    Very high level of quality and overall comfort, fit for me is outstanding. Only complaint is the straps kind of roll up very thin and are uncomfortable unless you take the extra minute or so to flatten them out before your ride. Also, they do run quite small, best to size up.

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    Thank you for your feedback.
    Reviewed 8/13/2020
    by Timmy B
    Overall Rating
    Nice bib short but

    These are my favorite bibs, I ride them on centuries all the time. They are mostly comfortable except for the fit around the bits and pieces. Like I said I ride these all the time on long rides, great pad too, it�s just a little tight in the front.

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    Thank you for your feedback.
    Reviewed 6/25/2020
    by Drerle
    New Jersey
    Value Rating
    Overall Rating
    3 of 4 customers found this review helpful.
    Beautifully made shorts

    High quality shorts that prioritize low weight over durability. These shorts are gossamer thin. I poked a small hole in a leg that I had the tailor fix for $20..

    The pads seem to extent more laterally than Im used to.

    Next time I may select a lower level pair of Castelli bibs for thicker more durable material.

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    Thank you for your feedback.
    Reviewed 6/21/2020
    by Jess
    Overall Rating
    2 of 2 customers found this review helpful.
    Excellent bibs

    Fantastic bibs, every bit the quality and comfort of Assos at a fraction of the price. Only caveat is they run small. Im 59 155lbs and Im a large.

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    Thank you for your feedback.
    Reviewed 11/14/2020
    by PBA_Biker
    Cycling Enthusiast
    Hampton Roads, VA
    Overall Rating
    Extremely comfortable for long rides

    I wore these bibs for the first time on a 82 mile ride, and was very please with the comfort.

    Was this review useful to you? Yes/No
    Thank you for your feedback.

    We are committed to delivering outstanding value and service to our customers, every day.
    Try us today to see why so many of our customers come back again and again.

    *Orders received before 3:00PM Pacific time are shipped the same day (Mon-Sat). Orders over $50
    are shipped free (USA only, excluding AK and HI). Some exceptions apply. See Shipping for details. 07


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