Anticipating pavement to Fairbank and a smooth-trail ride along the San Pedro River, I removed the big Panaracer knobbies and installed WTB Vulpines on the mountain bike last week. I scrapped the river ride when the weather turned cold, but left the tires on. The Vulpines came with the D440 and I had replaced them with Michelin City tires for commuter duty. They'd been in storage since.
When I set out this morning, I had my doubts as to whether the semi-slick tread would have enough traction for Brown Canyon, but didn't have time to swap them out. As it turned out, the Vulpines were fine on the initial steep climb (7:45 today; a 5-second improvement), and even gripped well on the scabby patches of snow and ice.
I was leery of the ice and kept my speed down and my hands soft on the grips as I crossed it, but the only spot that posed a problem was the steep downhill about midway between the top-of-climb gate and the water trough. The bike slithered badly, so I dismounted and walked it gingerly over the last few feet.