Freeze/Thaw Explained

    Former President
    Board Member

    December 16, 2018, 10:01 PM

    Throughout the winter, and especially in the early spring and late fall,  you’ll often see Freeze/Thaw in the trail conditions.   When the temperature is dropping at night, but near or above freezing during the day, the trails can be fabulous, or terrible, so please keep the following in mind.  Try to get out early in the day (as in, first thing) or stick to north facing slopes, and you’ll be rewarded with trails that are fast, grippy, and fun.  As soon as they start to thaw, which can happen well below freezing on a south-facing slope, they turn into a particularly soupy form of mud.  When our local clay soil freezes, the water expands; when it thaws again, and the water contracts, the soil has been aerated, holds more water, and is less cohesive.  When it gets ridden through, the tires push this soft mud to the sides of the trail, where it freezes again, thaws the next day, and gets pushed further to the side with deeper ruts.  After a few cycles of this, the trail is permanently cupped, holds water all the time, and erodes more with every storm, until it is unrideable, or someone spends valuable time repairing it.  So please, ride the frozen trails and avoid anywhere you are leaving a rut.  Your trail volunteers and fellow riders will thank you!