Castelli Mondiale Bibshort

New for summer 2016, the Mondiale bib shorts are Castelli's top of the line design, promising to be the most comfortable and luxurious bib shorts it's ever made. In a departure from how these things generally work, you won't see any of the pros wearing them. We'll come back to why that is, but they're missing out – these are the best bib shorts I've used. Comfort from Castelli's excellent Progetto X2 Air pad is a given, but the fabric used is unlike any that Castelli has used before, combining comfort, support and a seriously classy feel.

Castelli has dropped the Body Paint bibs from its range, but some of their DNA lives on in the Mondiale, specifically in the exceptionally low seam count. Until really not that long ago, you'd pay more for shorts made from a higher number of panels, as they were reckoned to offer a better fit. Thing is, more panels equals more seams, and the seams are rarely the most comfortable part of anything.

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With the Mondiale, the only seams on the lower parts run down the inside of each thigh, and up the middle front and back. In a first, as far as I'm aware, Castelli has taped these seams on the inside with a narrow strip of soft fabric tape. Not for water resistance – none is claimed here – but just to maximise comfort.

The major news in terms of the construction of the Mondiale bibs is the use of a brand new fabric called Cinquanta. It's 50% Lycra, a higher percentage than seen on most shorts, with the balance being polyamide. It's pretty classy looking and feels super primo too. Despite the high Lycra content, it's not significantly more stretchy than that used in most bibs, and certainly nowhere near as elastic as the knitted fabric used in Howies bibs, for example.

You can't sublimate graphics onto the fabric, and that's the reason you won't see the pros wearing the Mondiale in races – it is only available in plain black. Fans of big logos, these are not your shorts. Instead, there's a very slick silver Castelli logo stuck on the left leg next to a small scorpion, and that's it. Both are remaining firmly in place thus far. I really like the minimalist, classy look.

When you put them on, the Mondiale bib shorts feel more supportive than Castelli's other top-end shorts, the Free Aero Race. The fabric sits flat against the skin and the fit is excellent. My only quibble was that I found there was a little more pressure around the groin area than I would ideally have liked. Per Castelli's sizing chart, I fall between a medium and a large. This is classic Italian sizing – in reality a medium would have been uncomfortably tight and I'm actually between a large and an XL (as with other Castelli shorts and tights). Consider sizing up, in other words. I tested a large, although in our pictures the model (not me) is wearing a medium.

It is quite remarkable how it is possible to design bib shorts which fit this well with so few seams. On long rides, I found I never felt the need to adjust the position of the shorts – they stayed perfectly in place for hours. Around the thighs, there are gripper strips bonded inside the openings – 30mm-wide bands with "Mondiale" written in lightly tacky letters. Unusually, it's completely invisible from the outside, contributing to the overall classy looks.

The bib straps themselves are also very comfortable, being made of raw-cut seamless fabric. At the front they are lined on the inside with the same red tape as used on the leg openings. The panel at the rear, already made of ultra-lightweight fabric, is perforated to help keep you cool.

I've not really talked about the pad yet; it's the same Progetto X2 Air as Castelli uses across its high-end bibs and tights, and as we've reported previously, it's pretty close to perfection. It's quite a complex assembly with two layers that can move independently of each other, and perforated viscous pads that sit under the sit bones, made of a sort of ultra-soft silicone.

The top layer is made of really soft microdenier fabric with a "bacteriostatic finish". Below this the foam is of varying density and varying thickness, putting padding where you want it and not where you don't. There are perforations through the foam to allow the movement of air, and even riding hard on the hottest of days, I never had any discomfort.

I've owned another pair of Castelli bibs with the same pad and found it consistently comfortable there too. However the various bits of foam and silicone did start to peel apart after a couple of years of regular but not intensive use, on which basis durability may not be on a par with the best.

In the testing period I had no such issues – only the small red stripe between the shoulder blades started to peel off, which has no functional effect that I could determine.

> Check out our guide to the best  bib shorts

A couple of other details to note. As the Mondiale isn't marketed as racewear, there is no radio pocket on the rear. If that's a requirement for you, you've probably got someone providing your clothing anyway. Finally, an interesting detail which is invisible from the outside. Above each hip there is a large rectangle of the same Cinquanta fabric bonded to the inside of the main panel. I couldn't find any explanation as to its function, but it seems likely that it is intended to contribute to the overall fit, reducing stretch in this region to keep the fabric flat against your skin.

At £190, these are the most expensive Castelli bibs yet, although still some way short of top end Rapha or Assos pricing. A lot of us would struggle to justify that sort of outlay, but if that's your budget, they should definitely be on your shortlist. They're the most beautifully made and comfortable bib shorts I've used.

Verdict

Stunning luxury bib shorts at a premium price – if you can afford them, you'll love them