Kalas Pure Z bib shorts

Experience supporting pro teams shows in the Kalas Pure Z bib shorts, with their good compressive fit and a chamois that's comfortably longer lasting than their four-hour rides claim. Check the sizing, though.

You may not have heard of Kalas, but it's the official kit supplier to Alpecin-Deceuninck and the Great Britain Cycling Team, so there's some provenance there. These Pure Zs are among the least expensive bib shorts it produces, but that doesn't mean they're lacking in features or comfort.

I had an initial issue with fit. The Kalas sizing chart measures hip circumference rather than waist, and recommends that if the value falls between two sizes then to choose the larger one. Going on this I was a solid Size 4 and, while things were generally okay, the shorts were sloppy and unsupportive around the middle.

After an incredibly helpful chat with the Kalas folks, I sized down to a 3 (the Pure Z bib shorts come in seven sizes, so finding the perfect fit should be easy). Interestingly, some Kalas shorts have 'Extended Sizes,' where if, say, you're tall and skinny and want the width of a medium but the height of a large, you can get that. Unfortunately that's not available for the Pure Zs.

For those who like to remain stealthy, or want a plain black pair of shorts that will match anything, there's just a sewn-on Kalas patch on the right leg (you could even unpick this if you wanted) and a thin line of small reflective logos along the edge of the thighs, lined up like mini Pac-Men.

The panel layup is quite sophisticated for the money, and the large side panels have a waffle pattern due to the inside having a cross-cross mesh of elastic – it's there because then a lighter weight fabric can be used while still retaining compression. It also holds the fabric away from the skin a mite to aid breathability.

The pad is a perforated antibacterial Zoom X one from Elastic Interface. It comprises three different layers of padding: the outer perimeter is very lightly cushioned with a large area up front, the central section is made from two islands of padding that mirror the shape of a saddle, and there are two tiers of thickness.

It's just the right mix of squishy yet firm at its thickest point, and it does its job very well, as you might expect from a brand that supplies kit to pro riders – the chamois is one that you can sit in all the long day and not be niggled by. Kalas recommends these shorts for rides up to four hours but I reckon you can extend that by quite a distance... your bum's mileage may vary, though.

There is one slight oddity to the chamois in that the design of the large front section of thinly padded material ahead of the thick padding does encourage the, erm, contents to nestle more front and centre than other shorts, which could be considered showy by some.

At the end of the legs is a 70mm-deep band of elastic, with the bottom half augmented internally by a thin layer of silicone gripper to help things stay put, and it works very well to spread the compression of the hem across a broad swathe of thigh, banishing sausage leg and keeping the legs of the shorts securely in place while being unnoticeable.

The bib part of the shorts is constructed in two halves. The front is a strap that's very stretchy top to bottom but less so laterally, and on top of the shoulder it meets the rear which is a mesh panel with a double-stitched hem. It works comfortably well, keeping things taut without any digging in.

The bibs are cut low in the front, which helps with mid-ride comfort breaks.

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While these shorts fitted absolutely perfectly everywhere else on me, they were the smallest bit unsupportive across the upper thigh and crotch area at the very front of the chamois. It was not enough to take any comfort away from the rest of the shorts, especially in the sitting department, but was especially noticeable when hunched in the drops (when there was bunching) or when standing up climbing (when there was vagueness and movement).

It's a minor niggle, and I think maybe caused by the large front section of the chamois that helps hold the front of the crotch proud of the body, combined with my lanky physique. Maybe the Extended Size options of Kalas' other shorts might work for me.

Value

The Pure Z shorts have a fight on their hands with the Assos Mille GT Bib Shorts C2 which for a little bit more money (£125) perform well over longer rides, with the short legs seemingly the only downside for our reviewer.

The Stolen Goat Men's Climbers bib shorts come in at £120 and are great for warmer rides but look like they have you double checking the sizing and suffer from quality issues.

The Nopinz Souplesse Bib Shorts (£119.99) help fill this crowded price point and are another performance-led design, being a tight fit with good compression and a firm but comfortable chamois.

On the other hand, the Gore Wear Torrent Bib Shorts+ Mens are a chunk cheaper at £99.99 and come with an excellent Elastic Interface pad, but have a Windstopper front panel to protect your bits on cooler days which you might find surplus to requirements.

This is the cost in my head where I'm looking at nicely priced but good enough bib shorts that I can wear all day; ones that cost twice this much would be lovely, but this is the price/value/mileage sweet spot for me. The Kalas Pure Z bib shorts slot very nicely into this shaded bit of the Venn diagram.

Overall

These are great. The construction and detailing is very good, they fit very well almost everywhere and the chamois is cosseting enough for long hours in the saddle.

Verdict

Good shorts for the money with a race-snug fit and a comfortable 4hr+ ridespan