Snow Equipment Owning/Operating Cutting / Groving / Siping R-4 for snow

[gladehound]

I was wondering if you could explain this a little more. I don't really understand what is being said.

I'll try...

An uncut lug had no features to help it retain snow on it's surface. It is smooth. Like a slick.

On a hard surface, only the surface of the lug is in contact with the ground making the whole tire perform about as well as a slick. You get a little bite from the edge of each lug, but they get fairly round after you put a few hundred hours on them and don't bit well.

One of the basics of snow tire technology, is that snow gets better traction on snow and ice than the rubber used in most tires. So if you can get snow to stay on the contact surfact of the tires, it will get better traction in hard backed snow and ice.

Grooving does 2 things to help traction:

1. It adds biting edges to the tire (the edges of my groove are also much sharper than the edges of the lug)
2. Probably more importantly, and unlike the wide spaces between lugs that are too big to hold snow well, the small grooves trap snow inside them. Because snow sticks to snow (think of a snow ball or snow man) the snow trapped in the groove provides a strip of snow on the surface of each tire lug and additional snow actually sticks to these strips that are trapped in the grooves and spreads from these "anchor" points at the grooves across the lugs of the tire. On my tires, in the last snow, each 0.2 inch wide groove was causing a 1/2" to 1.5" wide strip of snow to stay on the contact surface of each lug for the length of the groove. If I made the groove longer, the strip of snow would be longer and improve my traction. This is why I said if I did it again i would make the grove longer. A few additional groves would also help.

Did that make sense??

 

[k0ua]

I'll try...

An uncut lug had no features to help it retain snow on it's surface. It is smooth. Like a slick.

On a hard surface, only the surface of the lug is in contact with the ground making the whole tire perform about as well as a slick. You get a little bite from the edge of each lug, but they get fairly round after you put a few hundred hours on them and don't bit well.

One of the basics of snow tire technology, is that snow gets better traction on snow and ice than the rubber used in most tires. So if you can get snow to stay on the contact surfact of the tires, it will get better traction in hard backed snow and ice.

Grooving does 2 things to help traction:

1. It adds biting edges to the tire (the edges of my groove are also much sharper than the edges of the lug)
2. Probably more importantly, and unlike the wide spaces between lugs that are too big to hold snow well, the small grooves trap snow inside them. Because snow sticks to snow (think of a snow ball or snow man) the snow trapped in the groove provides a strip of snow on the surface of each tire lug and additional snow actually sticks to these strips that are trapped in the grooves and spreads from these "anchor" points at the grooves across the lugs of the tire. On my tires, in the last snow, each 0.2 inch wide groove was causing a 1/2" to 1.5" wide strip of snow to stay on the contact surface of each lug for the length of the groove. If I made the groove longer, the strip of snow would be longer and improve my traction. This is why I said if I did it again i would make the grove longer. A few additional groves would also help.

Did that make sense??

You did a very good job of explaining that!
James K0UA

 

[V1Rotate]

Does that mean turf tires would be better because the snow will pack in between the tread blocks? What about R1s? They have very little tread suface that contacts the ground,

 

[Big Wave D]

Now you have a good excuse - er, I meant reason, to own another complete set of rims and tires for the 'real' work of summer.

Looks like you have a pretty steady hand.

 

[gladehound]

Does that mean turf tires would be better because the snow will pack in between the tread blocks? What about R1s? They have very little tread suface that contacts the ground,

You can find lots of discussion on this at TBN but here is my take both based on 30 years of experience with tractors and trucks.

The answer is... it depends. It depends on the snow, it depends on the vehicle and it depends on the exact tire within each category that you are using.

But typically, in deep snow you need voids that are big enough to clear themselves of snow but small enough to still pack snow tight enough so it holds together under some torque. How big that is depends on the snow. R-4s are great at this, R-1s might be good also but may have too much void space is some situations causing the snow not to pack tight enough to get good traction.

In packed snow / ice turfs will usually be better and turfs with lots of groves and sipes will be best.

And if you drive in deep snow, packed snow and ice and are avoiding chains, then a combination of a turf tires and R-4 tires may be the ticket! Oh, wait, that's what I just made Maybe we can call them R34 tires.

I'm very happy with the performance of the tires so far and will likely always get R-4 tires in the future over turfs or ags. I can always cut an R-4 to perform like a turf on hard packed snow, but I think it would be harder to do the same with an R-1 because you have so little contact area on the lug to work with. There just isn't much space to make groves and if you did you have to be more careful about the potential lug strength issues.

 

[Usta]

Very interesting post. Got me thinking (I hate when that happens)
I removed my R4's on the front and put on turfs for summer mowing but now run the turfs all year round. R4's with chains on the back. I now have a set of front R4's on rims on the garage shelf. Maybe I will groove them.

My problem is I have an area of slightly sloped lawn that I keep snowblowed and the only way I can do it is on a side slope and the front of the tractor slides down hill. Maybe I will pull the R4's off the shelf and groove them. It might help plus I have no use for the R4's anyway so no loss if it does not work.

Where can I get the knife/groover and what should I expect it to cost me?

 

[teg]

...Where can I get the knife/groover and what should I expect it to cost me?

See post #11 above or click on link below: about $60 + shipping (I don't know anything about this company - just from a google search) Need to buy a side hydraulic link first... but this might be next...

http://pitstopusa.com/b-4665-ideal-heated-knives.html

 

[slowzuki]

Many tire shops offer siping via an automatic machine. Done a lot up here. The siping head puts evenly spaced groves, about 3/4" apart. The head is sort of auger shaped and turns the tire as it sipes if I remember right. There is a bit more chunking with siping but not terrible.

Other option is screw in carbide studs for better ice traction. I wouldn't sipe in the area where the studs are.

 

[gladehound]

Very interesting post. Got me thinking (I hate when that happens)
My problem is I have an area of slightly sloped lawn that I keep snowblowed and the only way I can do it is on a side slope and the front of the tractor slides down hill. Maybe I will pull the R4's off the shelf and groove them. It might help plus I have no use for the R4's anyway so no loss if it does not work.

Where can I get the knife/groover and what should I expect it to cost me?

For best side slope performance, i would sipe and grove in the direction of rotation. Or in other words, perpendicular to the direction the lugs run. That way all your biting edges would be working to keep you from sliding down the side slope. I'd try a groove every inch and a pair of sipes half way between each groove. Since the tire is only for snow use when the rubber is rock hard and the traction low, I think the chance of the tire chunking is low as well.

Remember - the warmer the tire is before cutting (even with a heated knife) the easier it cuts. My tires were 10 degrees when I started and it took a lot of force to cut them Once I got the tires hot to the touch with the forced air heater, the heated knift went through them like butter.:thumbsup:

 

[Egon]

I'm wondering about the Rubber composition. Will it be too hard to get a proper grip?