As the name suggests, Mavic’s XA Thermo boot is a derivative of its lightweight XA Matryx trail shoe, designed as a dedicated winter mtb boot. It gets a + version of the Matryx’s Energy Grip Trail sole for solid pedalling without losing essential trail communication.
The shared, easy clearing Contragrip tread pattern uses a softer ‘Ice’ compound to make it more surefooted in cold and slippery conditions.
Design and construction
There’s a removable rubber block over the cleat slots if you’re using flat pedals rather than clipless.
The underlying upper is largely the same too, but it now gets a light layer of Thinsulate insulation in its makeup. It’s secured with a ‘Speed Lace’ system that you can get reasonably tight at first but it tends to relax gradually as you ride. It doesn’t have the backup wrap-over strap of the Matryx shoe to properly lock it down either. The stretchy rubbery ‘Thermo’ gaiter snugs down the upper when you zip it up though so as long as you’re not after complete lockdown it’s okay.
The gaiter also stretches up your leg to roughly average sock height and the silicon top section means it creates an impressively weatherproof seal to stop puddle splash or roost getting in. This makes it more weather protected and comfortable than most trail shoes in intermediate conditions.
The Thermo tag is potentially misleading though as it starts to struggle towards freezing point and any prolonged rain, wheel spray or puddle paddling will soon defeat the DWR coating on the gaiters. They’re certainly not as warm or weatherproof as Mavic’s own £26 cheaper Gore-Tex lined, grippier-soled Crossmax SL Pro Thermo boot which they’re meant to replace.
In addition, because it’s hard to peel the gaiter away from the upper, the XA Thermos take a long time to dry once wet which doesn’t help turnaround time for successive winter rides.
The real issue we’ve had - and Mavic assures us that it is only us - is that the threaded sections in the cleat plates are super soft. As a result, we’ve stretched both sets of bolt holes in both sets of XA shoes we’ve had and now these XA Thermo boots to the point where the bolts just spin uselessly and the cleats slide around trapping you in the pedal. That’s despite using a torque wrench for the tentative second go and the fact we’ve not stripped the threads in any of the other twenty-or-so shoes we’ve set up and tested over the same period.
The only solace is that if you have that problem yourself, the plates are replaceable, but you shouldn’t really be having that issue on a £225 set of mountain bike boots. The zip gets really sticky if it gets dirty too, so keep it wax lubed if you want to get out of them.
Tech spec: Mavic XA Thermo boots
- Price: £225.00 / $275.00 / €250,00
- Discipline: Trail
- Sizes: UK 5.5 - 11.5
- Weight: 946g (pair)