NDCC tire siping

[cranetruck]

To improve wet pavement traction, I intend to sipe my next set of tires.
The pattern I think will work is shown in image #1 below (drawn with white marker) and the siping tool is shown in image #2.
The cuts will be 1/4 inch deep and made with the blade installed in the tool, kinda like an exacto knife.
I'd like some comments on the pattern, potential problems etc.
Note that these are not groves, but cuts made by one stroke of the tool.
Thanks,

 

[jodka]

I just looked up the subject on Wikipedia and was impressed by this:
"A 1978 study by the U.S. National Safety Council found siping improved stopping distances by 22 percent, breakaway traction by 65 percent, and rolling traction by 28 percent."

It also mentions this:
"As is often the case, there are compromises. Winter tires, and "mud and snow" tires may have thousands of sipes and give good traction. But, they may feel "squirmy" on a warm, dry road."

Complete article is here:
http://en.wikipedia.org/wiki/Siping

 

[Jones]

Military has had oversized, chevron shaped sipes on NDCC tires for some time now though I see them mostly on the front steer tires. Sounds like a good idea for something as slippery as an NDCC tread pattern.

 

[rizzo]

all the siping I have seen has alot more cuts than you have. I would add more cuts on the middle rib. Not sure what pattern to use though. I think the outer ones are fine.

 

[cranetruck]

Thanks for the input Rizzo, I'll modify the pattern tomorrow.

 

[rizzo]

http://www.4x4review.com/tech/siping.asp

 

[cranetruck]

Hmm..that's totally different from what I drew up. Length wise? Better do my homework on this one. Thanks again Rizzo.

 

[spicergear]

Most of the aftermarket siping I've seen is done crossways on the tread. It's a shame the east coast doesn't have Less Shwabs around. Some of their places do tire siping.

Bjorn, I think because of the amound of open tread on the NDT a typical siping pattern isn't going to apply. The center of the tread, however, might act well with sipes across it.

 

[rizzo]

Hmm..that's totally different from what I drew up. Length wise? Better do my homework on this one. Thanks again Rizzo.

no, its all left to right (crossways).

zig-zag siping is suposed to be better. I have never confirmed this by tests I've done or read about. Like a lighting bolt. I would think that it would be extreamly hard to do by hand.

I agree with Spicer. I've heard jeepers talking about only siping the inner lugs. I'm gonna sipe my MTR's on my 1008, but not sure if I'm gonna do the middle or the whole thing.

 

[jodka]

I googled around looking for advice on sipe depth, angle and placement and then summarized what I found in a document attached to this message. There are two attachments, it is the identical content both in rtf and pdf formats.

Additionally, I contacted the National Safety Council to request reports on their 1978 study findings. Thought that it might describe the siping in detail. No luck. They confirmed that they had conducted that study but will not release the report.

 

[CCATLETT1984]

Discount tire around me does siping and so does the belle tire.

 

[cranetruck]

All things considered, I'll go with my original pattern, but with more cuts. Looked at a number of tire patents and it looks like there is still a lot of trial and error in this department. The original ones, 2,124,986 (Pipes) and 2,206,860 (Sperry) from the 1930-40's, are for shoes.
I have some old 900 tires that can serve as guinnee pigs. Pictures to follow.
Thanks for the feedback!

 

[rizzo]

sounds good, I'm very interested in the results. How about posting your finish pattern after you get done?

 

[greybird]

CT, the center rib is where the the rubber meets the road, and is also the place where the water can build up an lift the tire. For wet traction on roads, the center ridge is the place to put the sipes. You will notice that no modern tire has an unbroken center ridge. You've got to have channels for water to travel out, or sipes to give some grip

 

[cranetruck]

That's just it GB, I haven't found a good explanation for the action of the sipes.
When the siping "opens up" under the pressure, it kind of displaces the water without actually letting it out. The siping also lets the tire conform to the surface better, it's supposed to make a big difference on ice where there is no water.

I guess cutting the sipes so that the water can be let out makes sense, but I don't want chunks of rubber come flying off. The rubber on the old NDCC's seems a lot harder than the rubber on some newer tires.

The image below shows my left front tire after an extended run on the highway. The contact area is 7-8 inches wide and includes the "lugs". Tire pressure is about 70-72 psi.

 

[cranetruck]

A couple of images of today's activities.
The tool cuts six slits in one pass and that's all I'm going to to, I start at the outside of the contact area and finish close to the center of the tire.
The sipes are difficult to see, looking like fine lines in the rubber.

 

[cbvet]

Checked with a Discount Tire in South Bend Indiana. They said $10 per tire, any size tire.
I may try the fronts.
Eric

 

[cranetruck]

Eric, if you do have it done, please let us know what pattern they use, how many sipes/lug etc.
I understand that if a machine is used, some edges may be cut and rubber torn off.
Thanks,

 

[cbvet]

Tire Siping

Bjorn,
First chance I get, I am going to take a spare tire & wheel & see how it comes out.
I'll take pictures, then see if I can figure out how to attach them.
Eric

 

[cranetruck]

Went ahead and siped both front tires today. No compliated pattern, just cutting from the outside towards the center on all lugs. Took about 10 to 15 minutes/tire.
I also had the tires "flipped" on the rims since the outsides were beginning to cup. I have about 12,000 miles on them at this time. If the siping doesn't accelerate the wear, I should get another 10,000 miles out of them.