It can get extremely humid in Northwest Arkansas—where we did our testing for this year’s Bible of Bike Tests— and when you're losing fluids faster than you're able to take them in, there's only one material on the docket: Wool.
Ibex's latest mountain bike-specific jersey is made entirely of Merino, so even when it's soaked, it won't turn into a cold, sticky, smelly mess like polyester will. Despite its appearance as a heavy, cool-weather garment, the Enduro Half Zip is the perfect companion during hot, muggy days in the saddle.
The short collar and ¾-length sleeves make it look hotter than it is, but the material is in fact very thin and airy. The sleeves keep the sun off your arms, without overheating them, and because wool moderates temperature so well, it's actually warmer than a similarly thin synthetic jersey when the temp dips a bit.
The fit can be described as casual athletic. It's much looser than an XC jersey, but not overly baggy either, and it's long enough to wear with a pack without riding up. Because the material is thin and there's not too much of it, this jersey doesn't get heavy and saggy like other wool jerseys tend to.
There's a pocket situated diagonally on the lower back that seemed useless at first, but wound up being a perfect spot to stow a card and I.D. for post-ride beers.
$130 / ibex.com
Looking for something with shorter sleeves? We also love 7 Mesh’s Desperado Henley.