Siping

[VimyJ]

Have any members tried this? Seems like a good idea for heavy RWD cars.

http://www.can4x4.com/articles/siping.html

[Eswift]

maybe for our winters, as better snow tires often have this effect, but i doubt any all-season improvements on our car with that siping.

as winter tires with siping prove piss poor on dry pavement, i bet if you did the cuts yourslef, the effects would be similarly disappointing.

i would rather just get some winter tires, maybe with siping, and put them on the stock 15 inchers, and get a nice set of summer tires and slightly larger and wider wheels for the summers.

[Mayhem_J30]

so that's what i always see them doing on the WRC.

[VimyJ]

maybe for our winters, as better snow tires often have this effect, but i doubt any all-season improvements on our car with that siping.

as winter tires with siping prove piss poor on dry pavement, i bet if you did the cuts yourslef, the effects would be similarly disappointing.

I read a lot of articles about siping last night. Siping has been around since the 20's and was invented by a guy named Sipe. I read no comments about poor or decreaesed performance due to siping. In fact, many of the better articles were from Canada where they generally are more concerned about traction issues than we are here in the central part of N. America.

The primary reason snow tires perform badly on dry pavement is because of their agressive tread design. These tires only have about half the tread surface on the pavement compared to summer tires so their traction is correspondingly less.

The biggest benefit that I read was of increased tire life (attn. Q45tech). The siping allows the tires to run cooler slowing the vulcanization process. The trucking industry have run millions of miles on siped tires and have noted the increased tire life and increased traction. Other benefits were a quieter and softer ride.

The only negative reports had to do with poor siping jobs where inexperienced techs botched the job.

Tires can be siped as long as they have 50% of the tread remaining.

[Eswift]

well vimy, if you go do the skidpad, get your tires siped and then do the skidpad again, and there are improvements, ill be sold. unfortunately, i cant imagine anyone in chicagoland knows how to sipe correctly, looks like well have to learn the art ourselves

[VimyJ]

Actually, siping is done at Discount Tire centers locally in Chicagoland with the state of the industry equipment. Extensive tests have been performed and siped tires perform up to 20% better than non-sniped on skid path tests. Acceleration and braking are both improved in wet/snow/ice AND tire life is prolonged. This just all seems too good to be true!

BTW, I was impressed by Discount Tires. They gave me a great price (it didn't hurt that I also bought two tires for my wife's car when negotiating), balanced the tires perfectly and hand torqued the lugs. The guys at my outlet were also cheerful and energetic and the waiting area had a good selection of magazines for my wife. Why isn't she as interested in tires as me?:rolleyes

[EWT]

I read a lot of articles about siping last night. Siping has been around since the 20's and was invented by a guy named Sipe. I read no comments about poor or decreaesed performance due to siping. In fact, many of the better articles were from Canada where they generally are more concerned about traction issues than we are here in the central part of N. America.

The primary reason snow tires perform badly on dry pavement is because of their agressive tread design. These tires only have about half the tread surface on the pavement compared to summer tires so their traction is correspondingly less.

The biggest benefit that I read was of increased tire life (attn. Q45tech). The siping allows the tires to run cooler slowing the vulcanization process. The trucking industry have run millions of miles on siped tires and have noted the increased tire life and increased traction. Other benefits were a quieter and softer ride.

The only negative reports had to do with poor siping jobs where inexperienced techs botched the job.

Tires can be siped as long as they have 50% of the tread remaining.

I have a very hard time believing that a local $8/hr tire shop employee cutting tread blocks is going to improve traction for all conditions on a tire that a tire manfacturer spending millions of dollars developing and making molds for. One of the main features of a tire designed for dry traction are big tread blocks that don't squirm around and wiggle while cornering since that creates heat, which leads to a loss of traction and chunking if it gets bad enough. Cutting slots in the tread blocks defeats that and turns big tread blocks into little ones that wiggle around and rub each other, creating heat. It may help for bad weather traction since you're creating more irregularities on the tread surface, and might somehow increase tire life driving in a straight line (not sure why this would happen though), but I am very dubious it helps dry weather traction. If it did, you'd see them all over the place at the racetrack, and I have yet to see a siping machine there.

[VimyJ]

I have a very hard time believing that a local $8/hr tire shop employee cutting tread blocks is going to improve traction for all conditions on a tire that a tire manfacturer spending millions of dollars developing and making molds for. One of the main features of a tire designed for dry traction are big tread blocks that don't squirm around and wiggle while cornering since that creates heat, which leads to a loss of traction and chunking if it gets bad enough. Cutting slots in the tread blocks defeats that and turns big tread blocks into little ones that wiggle around and rub each other, creating heat. It may help for bad weather traction since you're creating more irregularities on the tread surface, and might somehow increase tire life driving in a straight line (not sure why this would happen though), but I am very dubious it helps dry weather traction. If it did, you'd see them all over the place at the racetrack, and I have yet to see a siping machine there.

The squirming question was addressed in one of the articles. Apparently, siping decreases tire temperature because it isolates frictional heat building. Heat is not transmitted as well through the tire compound becuase of the sipes. If fact, certain road race organizations ban siping as an unfair advantage. The trucking industry has reported much greater tire life.

That tires don't generally come siped from the factories does give me pause, however. Like I said before, seems too good to be true. However, your concerns have been addressed in the articles and seem not to be a detriment to performance but rather an improvement.

[Eswift]

well VImy, im going to hold out on the siping until i can get some more info, but its a very interesting topic you have raised.

if you dont mind me asking, which discount tire location did you go to?

i too have been impressed with discount tire, but i never knew they did the siping.

[EWT]

The squirming question was addressed in one of the articles. Apparently, siping decreases tire temperature because it isolates frictional heat building. Heat is not transmitted as well through the tire compound becuase of the sipes. If fact, certain road race organizations ban siping as an unfair advantage. The trucking industry has reported much greater tire life.

I'm still skeptical. Just because companies who provide the service and machinery to do it say it's the greatest thing since sliced bread doesn't mean it really is. As far as the racing orgainizations banning it, what are the specifics? I've never heard of such a thing. If the track is dry, the ultimate in traction is a slick with no tread pattern (or siping) whatsoever. DOT legal race tires have as little tread as possible with big solid blocks on the outside edge. Most of the "tread" wears away fast, only leaving one or two grooves, with the rest of the tire effectively a slick. The whole thing smacks of snake oil to me. If there really were these dramatic performance improvements with no downside, tire companies would sipe tires from the factory.

[maxnix]

Siping is primarily done for snow traction in the Pacific NW. Wet traction is not aided by most accounts. For dry, there is a detriment of stability when subject to a lateral load.

I think it is an old technology for hard rubber tires that didn't perform in snow.

[ninjak84]

so that's what i always see them doing on the WRC.

Well now it makes sense!This idea seems good for me, since winters are brutal up North....

[Eswift]

i know they do custom siping cuts on rally cars and it makes a tremendous difference for each individual run. The driver makes a judgement on how many cuts are to be made from the slicks, and often ends the day pissed at himself about his decision. seems to me that siping is definitley good for some slippery surfaces, i.e. snow for a normal car or rally HP on unpaved roads, but the amount of fine tuning necessary makes it impractible for the street. maybe for the winter, but again....just get snow tires with those mini channels built right in. all the good snow tires are molded with sipes now, look at tire rack.

[VimyJ]

i know they do custom siping cuts on rally cars and it makes a tremendous difference for each individual run. The driver makes a judgement on how many cuts are to be made from the slicks, and often ends the day pissed at himself about his decision. seems to me that siping is definitley good for some slippery surfaces, i.e. snow for a normal car or rally HP on unpaved roads, but the amount of fine tuning necessary makes it impractible for the street. maybe for the winter, but again....just get snow tires with those mini channels built right in. all the good snow tires are molded with sipes now, look at tire rack.

Now that is an idea that piques the imagination. All surfaces are slippery to one degree or another. If siping does increase grip in a positive way and keeps tires cooler, then you could have angled sipes on the edges for cornering and perpendicular sipes in the center for acceleration and braking.

I did another search on the topic looking for passenger car applications that I could paste here for the edification of the membership. However, they almost all dealt with off roading and the trucking industry. (There was a scientific siping study done but I don't understand Japanese)That said, the heavy truck industry aspect is interesting.

Heavy trucks are extremely hard on tires in a way that must be exponential compared to passenger car use. The trucking industry seems sold on this concept because the new siping technolgy is revolutionizing the old concept. The sipes must be cut not molded. Perhaps this is also why tires might not come siped from the factory. Would the tire industry be doing itself any favours by making all tires last 25% longer (50% longer by some accounts)?

I would be hesitant to sipe my brand new tires but I might consider it when they're down to 50% tread.

[Eswift]

I would be hesitant to sipe my brand new tires but I might consider it when they're down to 50% tread.

i like that idea, because worn tires get progressively worse on anything but dry pavement. i would be interested to see the results.

when my tires wear down, i would be willing to check eccentricity on both rear tires, make sure they are comparable, and then sipe only one side. put maybe 5k more miles on and then compare.

Ive got nearly all my tread at this point though, it might be a while until the necessary experimental conditions present themselves.

[Q45tech]

Slicks [100% SOFT rubber no groves no sipes no nothing have the greastest traction in dry and even moist roads.......as long as the water is not thick enough to upset the molecular bond between the road and the rubber..........water is a solvent .........once the water is more than say 2/32" thick the tire will rise and float on water unless you have drainage channels [tread grooves] for it to flow into, once these are full you hydroplane.

Important to keep the rubber at the temperature which is optimum for molecular bonding........why we have all temperature, winter, and summer tires and summer race tires as the optimum temperature for each compound has a very narrow window say 40F.................all temp all season spread the range by reducing [flattening] the point of peak adhesion so If a racing tire might do 0.9 G at 100F on asphalt, an all season might get to 0.8G at 75F.

A Summer tire might get down to 0.55-0.6 G at 30-40F whereas an allseason might be 0.65-0.7F all depends on compound........why many all seasons have dual compounds as do Expensive quality snow tires to avoid then melting like butter on snow free highways at 50F.

[VimyJ]

well VImy, im going to hold out on the siping until i can get some more info, but its a very interesting topic you have raised.

if you dont mind me asking, which discount tire location did you go to?

i too have been impressed with discount tire, but i never knew they did the siping.

I bought my tires at the Elgin location but they don't have the siping equipment. The nearest Discount Tire siping location to me is in Bloomingdale according to their web site.

[VimyJ]

Slicks [100% SOFT rubber no groves no sipes no nothing have the greastest traction in dry and even moist roads.......Important to keep the rubber at the temperature which is optimum for molecular bonding

Hmmm... Since siping is reported to reduce tire tempeature would this be counterproductive to balls to the wall road racing? F1 tires are stored in heated blankets so that they will have the maximum grip when changed on to the car and even then the tires are not up to racing temperature. If the sipes reduce temperature then this would reduce the "stickiness" of the tire compound on racing slicks. Of course, these F1 teams also have an almost infinite supply of tires for any track condition.