Castelli Free Aero RC Bib Shorts

Castelli's updated Free Aero RC bib shorts are its best ever, combining a superb level of comfort with plenty of support and some neat features. Plus, the Progetto X Air seamless seat pad is among the best out there.

Castelli has simplified its Free Aero shorts in some ways, halving the number of panels used in the lowers from 10 to five – and so reducing the number of seams. The danger with doing that is that you don't get such an anatomic fit, but these are superbly comfortable throughout.

The lowers are made from what Castelli calls Forza 2 which is apparently 'a brand-new 215g/m2 double-face circular knit fabric with a 32% elastane content' (the other 68% is nylon). That's quite a mouthful but the bottom line is that I found the shorts to feel supportive without being at all restrictive, although any matters of fit will depend to some extent on the individual.

The fine gauge of the yarns is designed to wick moisture away quickly. Although I've not had the chance to wear these shorts in super-hot weather, I've used them indoors on the turbo and they put in a good performance in this respect. They're a good summer weight.

The gripper panels at the ends of the legs on the previous generation Free Aero shorts are among those things that have been ditched. In fact, Castelli uses no gripper, no silicone, no elastic, no nothing to keep the ends of the raw-cut legs in place. It's an approach that the brand took for the Omloop Thermal Bib Shorts a few years ago, but smooth, lightweight summer fabrics are more likely to slip than thermal fabrics. Castelli says that it went through 28 different fabrics to get the right one.

I must say that I was a little suspicious, wondering whether this was just a way to save a little money in production costs, but Castelli is adamant that the idea is to prevent any discomfort from elastic or silicone. I expected the legs to ride up from time to time but, fair play, this never happened during testing – and I've been using these for about three months now both with leg/knee warmers and without – so the design certainly worked for me.

You get two small reflective tabs around the back which are pretty noticeable in car headlights, and the Castelli name is subtly embossed on the right leg. Castelli's scorpion logo comes on a badge that's sewn in place. That might seem like a small thing but, to me, is a step forward. Heat-on logos on Castelli shorts have been cracking and flaking off for years, making them look tatty even when relatively new (despite following the washing instructions scrupulously). You're not going to get that here.

The previous generation Free Aero shorts had a little pocket sewn into the back of the bib section. This has now gone, replaced by a larger and more easily accessible pocket right at the top of the lower section. Assuming most of us aren't going to stick a race radio in there, it's big enough for a mobile phone, keys, emergency Snickers bar, or whatever.

The straps are super-light and highly breathable, and they don't get heavy with sweat. They're also very stretchy so they'll work for a range of different torso lengths, and they're reinforced with thicker elasticated bands over the top of the shoulders.

The straps join together at the yoke between your shoulder blades and a narrow mesh panel provides the back section that holds the shorts comfortably in place. It's a bit of a cliché but you really don't feel the bib section in use. It just gets on with its job without adding any noticeable pressure or heat.

Castelli's Progetto X Air seamless seat pad is up there with the very best in the business. You get 3mm-thick viscous (gel-like) padding in the perineal and ischial areas and two different densities of foam. The thickness of the pad varies and it slopes away gradually towards the edges.

The soft and seamless top layer sits independent of the rest of the seat pad and it's stretchy enough to move with you as you pedal. Overall, I find the pad extremely comfortable and highly breathable, and I know loads of other people feel the same.

Something we can't measure is the aero performance. Castelli says that the drag of the Free Aero RC bib shorts is very close to that of the outgoing pair at 0-degree yaw but that the new versions make 'significant gains' when even minor crosswinds are brought into the equation. I'm just reporting the claim, though, not verifying it.

Priced at £175, the Free Aero RC bib shorts aren't cheap, but bear in mind that these are a high-level offering with a superb seat pad. You can buy shorts much cheaper, of course, but we've reviewed far more expensive shorts too, such as the £235 MAAP Pro Bib 2.0 that George tested last month and the Santini Redux Istinto shorts that Stu tested last year. Although each is very impressive, I think that the Free Aero RCs offer better value.

> Buyer’s Guide: 10 of the best bib shorts

If you're attracted by the Progetto X Air seat pad, it's available on Castelli's Endurance 3 bib shorts which cost £130, but the Free Aero RCs do enough to justify the extra spend.

Overall, the Free Aero RC bib shorts put in an excellent performance. The pad is exceptionally good, the comfort elsewhere is similarly impressive, and the price... well, it reflects the high quality.

Verdict

Excellent all-round performance and one of the best seat pads out there