Mavic's Propane jacket is aptly named since its extraordinary ability to retain warmth is akin to standing in front of a gas heater. While the somewhat puffy appearance may not be as trim looking as some other high-end cycling outerwear – especially the Italian stuff – that extra bulk encapsulates a highly effective layer of Primaloft insulation throughout and the result is one of the toastiest cycling jackets we've ever used.
It's so warm, in fact, that we'd only recommend using it on the coldest of days when other cyclists are far more likely to sit on a trainer. One memorable test ride took us out on an overcast day with a high temperature of just -4°C (25°F) and we were remarkably cozy with just a long-sleeved jersey beneath. Not a smidgeon of arctic air managed to punch through nor did we feel the need to work just that little bit harder just to generate body heat. In the event of precipitation, there's also a DWR coating to ward off light rain and road spray.
If it's really cold, the slightly looser fit leaves enough room for another layer or two and you can even crack out the built-in balaclava that's cleverly tucked inside the upper back of the Propane.
Mavic has done a good job of sealing all of the entry points, too, with a close-fitting collar, a slick double asymmetrical cuff that extends just enough over your gloves, and a half-elasticized lower hem that provides adequate coverage for your rear end but without bunching up around your stomach. There's curiously no protective flap behind the partially offset full front zipper but in fairness, we never felt a draft coming through, either.
Too much of a good thing?
In fact, we were almost too warm. While the Propane is insanely capable of retaining BTUs, it can be tough to shed the extra when the efforts levels climb. Mavic has fitted the Propane with zippered vents at the upper, outer chest and forearms but ultimately, we discovered those vents to be most useful only when moving reasonably quickly. Even with them all the way open we still had to open the front zipper all the way while climbing a modest seven percent grade at tempo pace.
Given that you're most likely to need to shed heat when climbing, we'd like to see Mavic add another set of vents at the back of the jacket to get some more effective pass-through ventilation – or at least makes the existing chest vents much longer. The Propane's loose-fitting shell also makes opening or closing the forearm vents a requisite two-handed affair.
Ample storage comes courtesy of a big zippered pocket out back, which opens up to reveal a trio of smaller elasticized pockets to help keep things separated. The main compartment offers up plenty of space – easily enough for a traditional long-sleeved jersey – but the sub-pockets are simply too small and deep to be useful. We were never able to fit more than three fingers in per pocket and it was utterly impossible to grab smaller items like mini-tools, CO2 cartridges, or keys without first pulling off our gloves. Like with the forearm vents, opening or closing the pocket zipper also requires two hands.
Minor issues aside, if warmth is your top priority for a cycling jacket, the Propane still fits the bill. It's certainly not cheap at US$349.95 but if you've previously backed out of going on a ride purely because of the temperature, this just might make things bearable.