Reviewed: Castelli Free Aero Race 4 Bib Short

With cycling shorts, the best are the ones that you don’t notice. You put them on, you start riding, they disappear. Their job is to stay out of the way, eliminate chafing, possibly add a little comfort at the point where your bottom hits the saddle. If you don’t notice them after seven hours of pedaling, they’ve done their job.

Castelli has gone in different directions when it comes to high-performing bottoms. At one time, they were minimizing seams. Their Body Paint shorts were constructed out of a single panel of spandex. After a few iterations, of those, they seemed to change course, improving their Aero Race shorts with many panels of differing material. Last year the Free Aero 3.0 Bib Short was their pro racing bib.

Their Free Aero Race 4.0 Bib Shorts are the next iteration. They say it’s not because rider feedback drove them to improve, but their own restless minds. Perhaps that’s why they went so hard with the presentation. These come in an attractive cardboard box, with artful paper shavings protecting them from rough handling. Don’t know how a good pair of shorts could survive travel without.

Castelli uses five different materials to construct the shorts. Giro4 gripper bands at the bottom of the legs. Vortex dimple panels on the sides for aerodynamics. Forza inner leg and back panels for durability. Stripe mesh bibs to make them disappear as much as possible. An unnamed spandex around the hips and butt. Progetto X2 chamois for long-riding comfort.

The first thing to report is that the shorts can be challenging to pull on, at least for the first time. Particularly if the leg gripper bands are contacting your skin. The 8cm tall bands aren’t only tight, but are lined with silicone stripes that are sticky when in contact with skin. The stripes run vertically, as opposed to horizontally, to allow for more stretch while still being sticky. Turn them inside out to make dressing easier. The panels are joined by a mix of hidden and flat-panel stitching. There were times in dressing when it seemed like we were hitting the limits of the fabric’s stretch—we tested out a Men’s Small, which is what we usually wear.   A fair amount of tugging, grabbing a bit of fabric here and there, to get panels in place.

Once on, those complaints and worries went away. The legs stayed put without feeling restrictive. The dimple panels on the outer legs stayed put. The center panels felt soft and exhibit incredibly comfortable stretch. If anything, out on the bike, the side panels and rear panel, which wraps around the hips,a seem to stay glued in place while the inner leg panels seem to stretch and contract while pedaling. Those inner panels have a rich hand both on and off one’s body. The front panel has something called Doppio V construction, which seems to mean that they’ve doubled up the fabric for the front panel. It seems to add a little compression in front, perhaps hide some anatomy, and it definitely eliminates the need for either a fabric strip on the upper edge or having a raw edge between the bibs. In that way, it seems to add some controlled stretch to the front panels.

The chamois is stretchy and multi-density, as are most pads these days. Here, too, Castelli goes in a slightly different direction. The top layer is smooth and super soft and sublimated, giving the impression of padding blocks, but the differences in thickness, from 9mm in front to 15mm in back, are underneath the top layer, not the top layer. The padding seems to have lots of dimples for getting sweat away from skin. It works great. We like both how dry, relatively, the nether region is with this chamois, and how it seems that the dimples actually help stick the pad to your body. When climbing on hot days, some pads get overwhelmed with sweat and get slippery, making for an unstable experience when grinding low gears up steep gradients. That was not the case here.

The bibs complete the bottoms. They’re a lighter material than we’ve ever experienced in bibs. You don’t so much as notice the material itself, but the thicker stuff that is sewn to the edges. It’s much lighter than any base layer or bib we’ve worn. Great touch, but we wonder about the long-term durability. That written, we’ve never had bibs fail before, and even the thinnest stuff we’ve ridden prior to this took years to lose stretch.

We’ve washed them several times, just turned inside out and placed in a sweater bag. Dried on low heat, the shorts still look almost as good as new, with the only blemish a little roughened material where the shorts contact the saddle embroidery.

We rode these easy days and hard, flat days and hilly. Our longest was a seven-hour epic. The shorts felt great all the way through. They even look good with salt stains.  And taking them off was much easier; the gripper bands stay put until you get the rest of the short past them, then they flip over and slide off.




Share your thoughts.