The Altura Esker doesn’t pack down as small as the Specialized SWAT or the Rapha Trail Lightweight, so it won’t fit in a bum bag, but it’s useful for stowing in a pack.

Although the promotional imagery shows it in a gravel riding/bike packing scenario, it should also be well-suited in the mix when browsing for the best mountain bike jacket. The fit is relatively tailored, despite being described by Altura as relaxed, with a drop hem for extra protection when bent over and hybrid elasticated cuffs that extend over the back of the hand. The sleeves, in particular, are tight, so if you’re packing big guns you might find them restrictive.

In terms of practical features, there’s a decent hood with elasticated sides and a drawcord that easily fits over a helmet and a high chest pocket that’s pretty deep and can swallow a phone. In fact, arguably it could be much smaller, since the only thing you’re likely to keep in it is a phone, and maybe a credit card or car key, and having that extra layer of fabric doesn’t help moisture transfer.

The fabric is relatively lightweight with a 2.5 layer construction, a waterproof zip that moves freely, taped seams and a series of vents around the midriff protected by storm flaps. Below this line the fabric has a generous four-way stretch, above that it’s much less elastic. And on the bike this creates significant tightness across the back and under the armpits. It’s particularly noticeable in the elbows-out attack position, suggesting that it has been optimised for a narrower, tucked-in stance on a gravel bike.

While the outer face of the fabric has a pleasant, soft touch, the inside of the Esker is cold and rubbery next to bare skin. In terms of breathability it’s mid-pack, but we found some moisture inside at the top of our test climb, focussed on the sleeves and particularly the broad taped seams, which suggests they are the jacket’s achilles heel. Waterproofing was good, with water beading well and barely any getting in after our ten minute dousing.

Impressively priced at £100, the Altura Esker is undeniably a good-looking jacket with modern styling. But we found the fit was not well suited to mountain biking, the fabric was slightly unpleasant next to skin and the breathability was underwhelming for such a light jacket.