Robinhood150

Let me start off by saying growing up in southern California I'm no snow expert, but I've driven in snow a handful of times and have gone snowboarding a handful of times. I also know physics.

So...I think it depends on the type of snow we're all talking about. If it's deep, powdery, trail breaking snow then I've heard more surface area is better, thus the reason airing down is better. But if we're talking a couple inches of street snow then I would imagine there are two theories here.

1) skinnier tires will tend to break through to the hard surface easier, much the reason skinnier tires are said to be better for mud -- that is, they'll dig down past the mud until they hit hard packed dirt. Of course, if the mud is too deep then you'll just succeed in getting stuck.

2) Ice skates work by having so much force on such a little area (high pressure) that the compression melts the ice momentarily and allows the skate blades to slide by easily. I think skinnier tires, while they won't have enough pressure to melt the snow completely, will compress the snow enough that the tires will be able to grip the snow fairly well. The compression of the snow will also conform to the tread of the tire resulting in better traction. A skinnier tire will exert more pressure on the snow than a larger one, thereby compressing the snow harder.

As for the sand analogy...the main difference between sand and snow, is that the grains of sand will not compress and stick together like snow flakes will. So, having a ski for sand won't work well because the sand won't have enough of a foundation to support the ski. That's why it's much better to have a large contact patch and why airing down works so well. A larger tire will float on the surface.

And lastly, in a previous thread I think the general concensus was to put the chains on the rear of a 4wd vehicle because in an emergency stop situation the back of the vehicle won't slide around to the front.

ewarnerusa

Robin Hood, thanks for those theories. They both sound familiar and make good sense. I think I like #2 the most.

I think I've got some kind of Montana Macho Mentality that a 4x4 truck is invincible if driven properly, so I've never considered needing chains while driving on-road (I'm definitely not saying I'm right about that!). So when I think of using chains it is only for off-road deep snow conditions. When that is the case, I like the breakdowns of oly884 and zedex. I think the zedex's post summed it up well. "In off road situations in snow,chains on the front work alot more effectively . All your weight is up front. In snow the front wheels pull you and the rear wheels follow behind in the tracks left by the front. If you were to put chains on the back, the front wheels would plow somewhat and steering would be difficult as the fronts wouldnt have the same traction as the backs. Whats better in snow? Front wheel drive or rear wheel drive? Front wheel drive hands down."
This has been my experience, too, even when driving without chains. So I figure help the front wheel drive aspect of it out as much as possible, so chains on the front. I have only felt the need to use the chains one time, so I can't say I have vast experience with them. But I did put them on the front and locked the rear and I rallied like a tank through some deep pow.

mt_goat

Have you ever driven with a set of chains on? Even in 2WD on ice there is plenty of traction to get you going and to stop. It is a rough ride and you can't go very fast anyway.

I only said put them in the rear only because there is no way in hell they would fit on the front of my truck. My 33 inch tires just bearly fit without rubbing. If I was to throw a set of chains on the front I wouldn't have any fenders left after a few miles. Many of you have more clearance than I do though so maybe you could at least get some cables on there. But why? On the back will do just fine for any of the roads or passes in the US, and off-road you have even more clearance issues with wheels getting stuffed up into the wheel well.

ewarnerusa

good point. I am totally stock, but I did have visions of the chains ripping things apart in the wheel wells if the tires were any bigger. I guess I just need to get my truck lifted....

Glenn

Yes, I have driven with chains on, and yes, it's a rough ride and you can't go very fast.

Without chains, I would not want to be in 2wd on ice and snow.

Citykid

I just happened to be reading on this in the manual yesterday. No chains on the front tires and do not go above 30mph. This is from my Toyota 4Runner manual.

Here end'th the sermon.

mt_goat

I'm with you on that one!

jruz

It's all relative...that's why I said the tires would "float" (relatively). My point was that they do not put the tracks in the front and skis out back on a snowmobile, at least not one I've seen...

I dunno, from what I've see it would have to be really hard pack for them to climb. Otherwise you're just digging in deeper. The fact that our trucks are heavy comes into play here.

Sure, but only because the sand is more dense (I'm pretty sure). The same physics still come into play...in fact in snow you are more likely to sink.

oly884

I see what you're saying, but I've been it that stiuation. Yes you'll dig down, but you'll dig down to hard packed snow, or the ground. I was trying to go down a road where there was about 2 feet of snow on the ground. what happened was that i put the chains in the rear the first time, but what happened was that my front end couldn't stay on top of the snow and, #1 i couldn't steer worth a darn, and #2 I could tell that it was harder for my truck to push through the snow. So, my room mate said that he always puts his chains in the front. So, I put them in the front and i noticed a difference in steering, and also my truck went through the snow eaiser. It's all personall preference, type of tires, type of vehicle, etc. there are so many different factors that are present that it just becomes preference.

jruz

Yeah, I guess it's going to vary with the terrain. Probably best to just decide when you're there...and switch ends if necessary.

Jim