FOX DEFEND THERMAL JERSEY REVIEW
THE MOST VERSATILE JERSEY?
Words by Robert Johnston | Photos by Finlay Anderson
To layer, or not to layer? That is the question I find myself asking often on those cool days. Most of the time the answer is yes, but more layers tend to add bulk and can reduce comfort a touch compared with keeping it simple. Fox’s Defend Thermal Jersey hits the middle ground between a standard riding jersey and a layered combo, and has without a doubt been a highlight item in my kit bag this year for the less sunny days.
ABOUT THE FOX DEFEND THERMAL JERSEY
Fox sums up the Defend Thermal Jersey quite effectively in saying that it’s a “lightly insulated long sleeve mountain bike jersey”. Couldn’t have put it much better myself.
The Defend Thermal Jersey is made from a mixture of 64% polyester, 23% nylon, and 13% elastane, with a stretch grid insulation inside. These raised “tufts” of insulation balance warmth with moisture wicking, helping to keep you warm and dry as you ride.
The Defend Thermal Long Sleeve Jersey features a relaxed fit, with a dropped tail to offer improved coverage when in the saddle. Space has been left in the elbow area to fit pads underneath to stay protected. The black panels on the jersey are made from DWR-coated nylon, offering increased abrasion resistance in these higher wear areas and some resistance to light puddle splashes and rain showers.
Available in a choice of three subdued colors for this season (the color pictured is from last year’s collection), the Fox Defend Thermal Jersey is offered in sizes S-2XL and retails for $124.95/£99.99.
THE DIRT
The Fox Defend Thermal Long Sleeve Jersey is an excellent bit of kit. I typically run quite warm, but often find it tricky to strike the balance between warmth at the beginning of a ride in temperatures around the 9-12 Celcius mark (48-53F), without cooking midway through the first climb. The Defend Thermal Jersey hits the sweet spot for me, taking the sting off the initial chill and maintaining comfort once I’ve started sweating hard.
It was only on some less breezy days around the 15C (59F) mark that it became uncomfortably warm. Below 9C (48F) I typically needed an extra layer, such as the Fox Flexair Vest, to prevent a chill from setting in. Of course, different riders will have different insulation needs, but these are the figures that were applicable for me.
Fox has put some thought into the construction of the Defend Thermal jersey, boosting functionality and service life. The high-wear areas are also the areas typically subjected to the most water spray, so using a tougher but less insulated DWR-coated Nylon material here makes a lot of sense. It means that aside from some areas that have been caught by thorns hanging next to the trail, the Defend Thermal Jersey is showing next to no signs of use. And believe me, it’s seen some trail time.
The fit is spot-on for a relaxed fit XL. There’s plentiful stretch in the material without it sagging and feeling shapeless once it gets damp. It’ll move with you very happily, and for its insulative properties it feels quite light when worn. The sleeves strike a nice balance of sizing, where I’d be able to squeeze in a thin elbow pad to add protection, but they avoid being overly baggy and “flappy” when worn without.
It’s a pricey jersey, but the practicality and apparent longevity of the Fox Defend Thermal Jersey may make it a great buy for riders looking to boost comfort on the trails this autumn/fall and winter.
The Wolf’s Last Word
I’m a big fan of the Fox Defend Thermal Long Sleeve Jersey, thanks to its ability to take the chill off a cool day on the trails without being stifling once you’ve got the body heat up. It’s not a cheap jersey, but one I could recommend investing in as winter approaches. 
Price: $124.95 / £99.99
Website: Foxracing.com
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