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The Castelli Premio Black Bib Shorts are fantastic – they're comfortable on long distances, have an excellent pad, and deliver compression qualities, all the while feeling like they're hardly there. A couple of times the straps have twisted when on top of a baselayer, and they are expensive, but they are very impressive.
I took a look at the last version of the Castelli Premios in 2017 and found them a very impressive pair of bib shorts, so when the chance came up to test the newest iteration I jumped at it.
The first thing you notice about these is that the material is considerably thinner than almost any other shorts you're likely to have come across, with an almost papery quality. There are only a couple of other shorts I've used that feel similar, ashmei's Cycle Bib Short that I tested a couple of years ago being the closest.
However, it's a little simplistic to say that the fabric is the same across the bib shorts, because despite the leg and seat area being made up of only three panels, each of the same material, within each panel that same material has different qualities and thicknesses... without Castelli needing to include additional panels.
There is a lot going on in these shorts, so, starting at the bottom of the leg: Castelli has essentially sewn elastication into the material in a lot of little dots that stretch for the first 9cm from the bottom of the leg, in place of traditional silicone gripper. This means they sit close to the leg and keep the shorts in place without any uncomfortable pulling that you would almost certainly get if you had used a similar amount of silicone gripper.
Castelli has forgone seams and hems at the bottom of the shorts, instead going for a seamless laser cut which creates a close fit against the leg. This has a number of benefits, including reducing irritation and weight, and improving their aero qualities.
Above the elastication the material stays the same, but Castelli has added around 10.5cm of compression bands, which sit around the middle of your quads. While there are many shorts out there that offer compression, I found I could really feel it working here, despite it being the same material as both above and below. The material is also thicker around the thighs than it is at the front, to help support you better.
The manufacturing process for the fabric also means the shorts work impressively well in a wider range of temperatures than most: the thinner material wicks very effectively, but the tight weave means you can also stay comfortable in lower temperatures than you would in most shorts designed for wearing above 25°C.
As I mentioned, the amount of stitching is reduced significantly throughout by the shorts being made up of only three panels – one panel for each leg and a smaller central panel across the small of the back. This design is made possible thanks to the impressive amount of stretch in the fabric, so you don't need to rely on different panels to mould to your body shape. Castelli has also included an additional lining at the back of the shorts to avoid any risk of the thin material revealing more than you intended.
Castelli has used its range-topping Progetto X2 Air Seamless pad, which has variable densities and gel padding throughout, combining to make an undeniably comfortable chamois. It is soft and breathable too, so after a few hours in the saddle on a hot day you aren't left in a swampy mess.
The previous version of the Premios used the Progetto X2, which I liked, but this is a step up again. Much like the rest of the shorts, where the fabric thickness changes gradually, the pad also moves gradually from thickest at the back to thinnest at the front without any noticeable steps where different thicknesses meet.
Above the waist, a well-vented back panel allows heat to escape quickly, alongside two thin straps. In the past, these straps have had a tendency twist; it's one area of Castelli bibs that could have been improved. To try to combat this without losing the benefits of how flat they sit, Castelli has added a tab of thicker fabric that is meant to help the straps sit flat against the body. I found that this worked fine when I wasn't wearing a baselayer, but with a layer underneath they did occasionally still twist.
Aside from the occasional twisting, the straps offer a good amount of stretch and sit flat against the body; generally, throughout a long ride you almost forget they're there.
Given how technically accomplished these bib shorts are, combined with the number of innovations within the design, their rrp of £220 isn't surprising. They are a full £55 more than the shorts they're replacing, but I would say they're £55 better.
At this price point they are up against some big hitters, though. Jamie thought Velocio's Concept Bib Shorts were impressive, but they don't offer anything close to the level of innovative design and cost £235.
Probably the closest in terms of technological advancement are the Rapha Pro Team Powerweave Bib Shorts, and they are even more expensive at £275.
Overall, the Premio bib shorts are very impressive, and of the dozens I have tested over the past few years, they're the only ones that have struck me as an obvious jump forward. They aren't perfect – the straps did still occasionally twist, and they are at the top end in terms of price – but there is nothing else I could find that didn't impress.
Genuinely innovative bib shorts that feel like a technological leap forward – comfortable, light, durable and not cheap
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road.cc test report
Make and model: Castelli Premio Black Bib Shorts
Size tested: Medium
Tell us what the product is for
These are the latest version of Castelli's Premio shorts, which are focused on creating comfort and performance for long-distance rides. According to Castelli these shorts are a culmination of a 10-year-old idea, with technology finally catching up to the concept.
Castelli says, 'The Premio Black Bib Shorts are engineered to deliver premium long-distance comfort, strategically using the latest fabric technology to create a short that delivers big on comfort, support, speed and durability.
'The first thing that is notable about the Premio is what is missing: the seams and panels. This is because Castelli has created a new fabric that is woven to match the needs of various parts of the body, offering unrivalled comfort and support. The lower leg has a raw-cut ending with silicone backed yarn to keep the shorts in place, while the four-way stretch fabric in the thigh provides just the right amount of muscle support.
'The premium fabric extends into the back and is perforated for ventilation. Around the pelvis the fabric is slightly thicker to offer compression, keeping Castelli's top-of-the-line Progetto X2 seat pad in place, and avoiding any transparency issues.'
Tell us some more about the technical aspects of the product?
The premium all-conditions short
Gradient stretch woven fabric for the right support in the right place
Woven fabric weighs 30% less than comparable knit fabric
Perforated back bib panel with lie flat bib straps that don't bind at shoulders
Integrated gripper elastic at leg ending holds short in place without need for extra silicone grippers
Laser-etched logos with RossoCorsa at center back and black scorpion shadow logos at lower legs
Progetto X2 Air Seamless seat pad
Very well made with strong and tight stitching throughout and a unique construction process with only three panels in the shorts themselves.
They offer excellent performance, whether you're looking at fit, compression or comfort.
The material is thinner than some but feels as durable as anything else I've used.
Very good fit – these have a very impressive amount of stretch in the right areas without adding panels or impacting the compression qualities. It means they sit on the legs and shoulders flat and with minimal bunching.
The large size I tested could have passed as a medium in some other brands, but with the amount of stretch and how well these fit I don't think it was an issue.
154g for a pair of shorts that can be worn in three seasons is incredibly light.
The pad manages to improve on the previous version, which I loved, and makes these exceptionally comfortable shorts.
There is no getting around that these are very expensive shorts, but given the pricing of some of the competition and the genuine innovative technology used, they're not bad value.
How easy is the product to care for? How did it respond to being washed?
Very easy – I was using these in high temperatures for long rides and just chucking them in at 30 degrees, then popping them on the line, was fine.
Tell us how the product performed overall when used for its designed purpose
Very well, these are an impressive pair of bib shorts that genuinely offer qualities I have not experienced before.
Tell us what you particularly liked about the product
The material – the fact that it fits so close, offers so many different qualities, but remains so light, is incredibly impressive.
Tell us what you particularly disliked about the product
The only thing I found was that the straps would occasionally twist when worn over an baselayer.
How does the price compare to that of similar products in the market, including ones recently tested on road.cc?
They're expensive, but still cheaper than Velocio's Men's Concept Bib Shorts at £235, which Jamie found impressive but do not offer anything close to the level of innovative design. Probably the closest in terms of technological advancement are the Rapha Pro Team Powerweave Bib Shorts, which are more expensive still at £275.
Did you enjoy using the product? Yes
Would you consider buying the product? Yes
Would you recommend the product to a friend? Yes
Use this box to explain your overall score
These are probably the most exciting bib shorts I have reviewed – they feel like a genuine leap forward in terms of technology, construction, and what can be done with one fabric. They're excellent.
About the tester
I usually ride: CAAD13 My best bike is: Cannondale Supersix Evo
I've been riding for: 10-20 years I ride: Every day I would class myself as: Expert
I regularly do the following types of riding: commuting, club rides, sportives, general fitness riding, fixed/singlespeed,
George spends his days helping companies deal with their cycling commuting challenges with his company Cycling for Work. He has been writing for Road.cc since 2014.
When he is not writing about cycling, he is either out on his bike cursing not living in the countryside or boring anybody who will listen about the latest pro peloton/cycling tech/cycling infrastructure projects.