Pas Normal Studios Mechanism Bib Shorts Review: stylish, comfortable and great for fast-paced riding

The brand has updated its Mechanism bib shorts for 2025, including a more resilient bib strap construction to prevent any elastic fraying, as well as being more perforated for better breathability. Will the changes secure their place among the best cycling shorts for men?

The shorts are made up mostly of polyester along with elastane and have been designed with breathability and aerodynamic fit in mind. Wide elastic straps provide pressure distribution while keeping everything in place along with wide elastic hems on the legs of the shorts.

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(Image credit: Future / Andy Turner)

A four-layer ultralight foam chamois is used, aimed at providing plenty of comfort. It’s fast drying and anti-microbial to reduce friction and maintain cleanliness. Using multiple foam densities is designed to offer better pressure distribution and support across the various parts of the seating area, across soft tissue as well as bony structures.

(Image credit: Future / Andy Turner)

All the shorts use fully dyed fabrics and come in six colour options of the 2025 update and eight total. All versions save for the white, black, and navy come with contrasting white stitching. Sizes start at XXS and go up to XXL, and are true to size

As part of the update, the fit had been slightly altered so as to be better suited for a wider range of body types. Previously, some PNS bib shorts have pulled quite badly on the straps, which have felt almost too short unless very hunched over on the bike. With this update, the straps appear to be a touch longer, so feel more comfortable across a range of riding positions; however, being designed for high intensity fast paced sessions, they are at their most comfortable when riding in a low and tucked position.

(Image credit: Future)

In previous iterations, I found the elastic in the straps could fray over time. So far, the updated Mechanism bibs seem to be of a stronger construction, as well as featuring more perforations on the straps to reduce heat build-up. They’re wide too, so distribute pressure well, while at the rear, a panel in the centre keeps things in place without adding excess material. The straps also sit a bit more centrally on the body. I find this prevents any rubbing around the armpits, something I have encountered over longer rides with bib straps with a wider spacing. This, along with quite a high waist, does make nature breaks a bit more difficult, however.

(Image credit: Future / Andy Turner)

Features that have been carried over for the sake of performance and comfort are the large elastic leg grippers. Using a cross pattern of silicone grippers, these are really effective at staying in place, especially if you don’t shave your legs regularly. Keeping everything nicely in place is essential for proper interface between the body and contact points.

The contact point in this case is the brilliant multiple-density chamois. PNS has been using the same four-layer foam chamois, and this ultralight one is incredibly comfortable. Having the different densities means there is limited bulk where you don’t need it, but plenty of support exactly where you do. It’s fast drying and anti-microbial, so for long days in the saddle, it’s ideal as well as being a consistent performer during short high intensity group rides.

(Image credit: Future / Andy Turner)

On that subject, these shorts are specifically designed to be used across a wide range of summer riding conditions. The fabric is a bit thicker than some more specific summer shorts, but this never proved an issue, even in the high temperatures we saw this summer in the UK. What it does mean is that the shorts offer a nice level of compression, something that can be lost with more open-structured breathable shorts, such as the Rapha Pro Team Ghost bibs. This provides a good balance between comfort and muscle support that is great for high-intensity rides, while the breathable mesh at the front and rear of the body does well to dissipate heat.

(Image credit: Future / Andy Turner)

The shorts are offered in a wide range of colour options, even a very smart white option. Most of these use a contrasting white stitching on the panels, matching many of the Mechanism jerseys. It breaks up the block colour nicely, and personally, I really like it. Having a wide range of colour choices and size options also makes it quite easy to personalise your style either with matching colours or by creating a contrast with your chosen jersey. Function is certainly first and foremost for cycling kit, but it’s nice when the form is a match.

Interestingly, the PNS Mechanism shorts sit in what I would call the lower end of the pricing spectrum for high-performance designer brand bib shorts. Rapha were the first to hit the £300 barrier with the Powerweave shorts, but now several other brands have breached this barrier. £230 is still a lot of money for a pair of bib shorts, but in the current market, and for a pair this comfortable, it could be deemed as reasonable.

Q36.5 Dottore Pro are £250, with MAAP also in that region at £260. Castelli is a slight outlier with the Free Aero S at £199.99, as it has done brilliantly with its latest race range, bringing superb performance for the price. However, I would argue the PNS Mechanism is a bit more comfortable for longer rides, and the colour and size range is broader. Another nice addition of PNS is that if an item is purchased within two years and gets damaged in a crash or worn out, a 50% discount is offered on a new clothing item.

The Pas Normal Studios Mechanism bib shorts are a very solid offering. At £230, they are by no means cheap, but they actually undercut a good number of their competitors. Effective in a wide range of temperatures, the highlight of these shorts is the comfort, both for all-day riding and fast-paced high-intensity workouts. A huge array of colour options and a good size range are added bonuses. Only a slightly high waist that makes nature breaks difficult detracts from their overall appeal.