[LiquidSpin]

So now that parts of the eastern side of the US is finally getting some snow, I've been seeing more posts of people riding in the snow. Which is a good time but unfortunately, people are riding on snowy trails during the day when the sun is out and the temps go well above freezing. This in turn destroys the trails. A lot of people assume the snow on top is keeping the ground beneath frozen. Well, not always.

Just a friendly reminder to ride when it's still 30 or below. I know, I know for most people it sucks to ride in fridged temps and sometimes it requires us to get up super early but you'll help keep the trails in better shape and less work for the trail peeps.

Sorry to preach.

On a much happier note...when it is 30 or below using winter specific MTB tires is incredible. The rubber compound stays soft in colder temps unlike other rubber compounds which tend to stiffen up. The one's I ride with have tungsten carbide studs adding grip on the frozen ground. In addition I run lower PSI in my tires.

I tend to use 23.5psi in the rear and 22psi in the front. (I weigh 147lbs with gear on)
So much grip! They are worth it just to get a chance to ride on a lake/river I was lucky enough to experience 2 years ago.

 

[TimWebber]

ice spiker pros? its - 4 to 14 farenheit here in Edmonton. At 14f, direct sun perpendicular to slope will loosen the top cm or so if snow. Fat tires do kess damage. studs are only useful if the too is frozen or really cold and packed. Litsa awesome tires for this included 29*2.8 cake eaters.

 

[LiquidSpin]

ice spiker pros? its - 4 to 14 farenheit here in Edmonton. At 14f, direct sun perpendicular to slope will loosen the top cm or so if snow. Fat tires do kess damage. studs are only useful if the too is frozen or really cold and packed. Litsa awesome tires for this included 29*2.8 cake eaters.

It's pretty darn chilly where you're at and yeah those kinds of temps are prime for snow rides!
I've only ever ridden on snow when it was frozen on top once. It was a rare moment as it drizzled the night before and it stayed below freezing. It was like riding on asphalt and it was my favorite snow ride ever.

I haven't had any issues riding in the snow when the ground underneath is frozen with studded tires. Then again I've never ridden in deep deep snow.

And yes you're correct~ I'm running the Schwalbe Ice Spiker Pro's.

 

[BansheeRune]

If only these were available in 3.25 or 3.5...

Photo courtesy of LiquidSpin.

This tire has a very nice pattern to it. That would make some additional adventures come to be with Sarge III.

 

[Harold]

At 14f, direct sun perpendicular to slope will loosen the top cm or so if snow.

Definitely seen this, but IME, any slope that's not in the shade can turn to slop when the sun gets high enough in the sky. Seems to be about 10am in much of the US. What I see often enough is that a snow dump will occur before the ground is frozen. Then the snow insulates the ground from the colder air above and the snow melts from the bottom up. It might "look" like you're good to ride, even if you're riding early in the morning in subfreezing temps, but there's still slop hiding underneath.

 

[ctxcrossx]

Here in southern New England, I'm watching a beautiful blanket of snow slowly melt away with above freezing temperatures every day this week. Sunday was one of the best days on the snow, and it may have been the last of the season.

 

[Jayem]

Definitely seen this, but IME, any slope that's not in the shade can turn to slop when the sun gets high enough in the sky.

Well, I'd say it's more about the combination of air and ground temps, rather than just the sun. Yes, sun has a big effect, but at 0F and colder, it still isn't doing any significant dent to the snow condition. The clear and cold days are usually the best to ride, snow is squeaky-firm with so much traction. If the air temp is warmer though AND the sun is just as bright, it turns to slop. We even get that in December and January, when the sun is much more limited. Around 28 degrees, it doesn't take much to turn the snow to slop. Still freezes at night, but the damage is usually done in the day (massive ruts).

 

[TimWebber]

In Edmonton, our ground is frozen solid into May. Its not a factor... the snow will be gone by may due to temp n melt.

Temp is a factor now: not sure at what point but i think at or above - 10c. below that sun exposed slopes seem to be ok.. . However, only on slopes exposed to sun and most prominently those where the angle of incidence is closest to 90deg (perpendicular), it turns to slop super quick. A freeze in the night and riding is good until the sun is on the slope again... it can be a bit above zero and cloudy and u can ride all day (frozen ground will keep it mostly solid).

Right now solar radiation is king of slop.

 

[Harold]

Well, I'd say it's more about the combination of air and ground temps, rather than just the sun. Yes, sun has a big effect, but at 0F and colder, it still isn't doing any significant dent to the snow condition. The clear and cold days are usually the best to ride, snow is squeaky-firm with so much traction. If the air temp is warmer though AND the sun is just as bright, it turns to slop. We even get that in December and January, when the sun is much more limited. Around 28 degrees, it doesn't take much to turn the snow to slop. Still freezes at night, but the damage is usually done in the day (massive ruts).

Sure, this effect only becomes relevant above a certain temp. Below that and snow tends to sublimate instead of melt.

And yeah, the exact temp that this occurs DOES depend on a host of factors, including air and ground temp, but also the slope angle and aspect and the position of the sun in the sky. But the sun itself is absolutely relevant. If the sky is cloudy and you don't have the direct sunshine, temps will be MUCH closer to freezing before you get significant melt. If the only thing you change is the fact that the sun is present, then that melting can happen at far lower temps. I've seen actual melty mud at 20F air temps (where the ground was actually frozen before) and this started at around 10am because the sun was high enough in the sky, with a fairly direct angle on the section of trail in question.

For most people riding in the wintertime, they're going to encounter conditions like this, at least at some point over the winter. It's important to acknowledge it since freeze/thaw tends to be when a lot of trails are most sensitive to being thrashed by people on them. Not to mention freeze/thaw mud just sucks to ride in. It's been the primary condition to avoid in most of my mtb riding years (and places I've lived).

 

[LiquidSpin]

It was fun if only for one ride. Hopefully next winter I'll have more chances.