Pugsley

You need to get in 3 hours of tempo, but it's -25C, the wind is howling, and the trail is covered in snow, ice, frozen foot prints, and snow drifts. The answer is the Surley Pugsley, a beast of a bike that makes the aforementioned ride a blast.

No those aren't carbon aero rims. Endomorph 3.7" tires are the largest volume production bike tire available.