siping

[hawkwind]

Anyone heard of and or tried siping to increase traction ,talking about street radials not landspeed tyres  siping = cutting small groves across the center of the tyre about a quarter of an inch apart and up to a quarter deep,a lot of the off roaders sip their tyres over here to increase traction on very slipery surfaces
Gary

[GeneF]

I grew up in the cold country (So.Dak.) and in the 60s this was a fairly common practice for winter traction. Dirt track racers have used this modification also. The theory, I believe, is that as the tire rotates and contacts the surface the slits open up like a "mouth" and "bites" the surface.
 Recently there was a ditty on the local tv news telling about this service being available at some local tire shops. They came across as this being a recent innovation but as I stated its been around since at least the 60s and probably long before that.
 BTW- Most tire grooving tools that dirt racers use come with a siping blade in the blade assortment.

[Glen]

I don't think it would be good practice at higher speeds as the tire chunking would create a ride you wouldn't want. Salt tends to pack in any grooves and the inbalance alone is enough to shake your fillings loose.

[JackD]

"Regrooving" started when the first tire wore out the original tread.
It is very common in many racing uses and for lots of reasons that include "Old Spanish custom".
It is not useful for  Bonneville type application because you are not using the grooves to clear away loose surface material including water.
While the individual tread blocks that remain will have a higher down force on the ground (that is good), the groves will dig up the surface and deposit the material in front of the next block in line and reduce it's grip(that is bad).
Siping is designed to clear the debris to the side so it becomes you buddies problem(that is good) unless you drive through the same spot again (that is bad)
The fastest vehicles have no tread pattern at all for a good reason.

That is not engineer or legal speak, but just enough information for you to act on by additional research or stop there.
The final decision is yours and the question posted here also serves to answer for others as well.
They can chime in with more information and other views but everybody is better for it.
Nobody should place themselves above the others because hopefully we are all in this together.
I am however a little shy and this has helped to bring me out and perhaps I was just pulling your cane.   LOL

AMEN (this is Sunday)

[GeneF]

"Back in the day" they used to do it by hand, but today they have fancy smanchy machines to do it for them 

 http://www.sipers.com/sipers/how_siping_done-video.html

[firemanjim]

Les Schwabb tire stores do it on a regular basis.Supposed to aid in wet weather traction.Just had the wifes Honda done,no idea if it actually works???

[JackD]

Actually "regrooving" a standard tire is not allowed by DOT regulations it was built under.
It was common practice in used car lots to freshen up an otherwise bald tire.
The only tires for the street that allow it are marked as such.
They are seen on buses etc. in commercial fleets.

[hawkwind]

Thanks  (and a safe and fast new year to all ) Glen on a good year Gairdner has almost nill salt compaction just a fine dusting of salt ,but yes I was wondering about chunking the tyres at higher speeds ,though no one has had problems with tyres yet of any sort ,though I suspect its got a lot to do with our lower speeds, Thanks Jack I see your as adroit and incrutable as ever  though my  conundrum still persists
Gary

[Richard Thomason]

Siping is not regroving. I have all my vehicles tires siped for winter weather. Addmitedly they are all on 4-wheel drive trucks, but I used to have a Z-28 that I also ran in the winter, and the siping for sure made a difference you could tell. I really don't think it would help on the salt mainly because a really fast tire doesn't have enough rubber to sipe. However it remains a somewhat interesting concept. Would like so see some slower cars try it and compare. However I guess by its very nature a slower car would not have the traction problems that maybe we are trying to compensate for.

[JackD]

Same tool , same reason, different dialect , different blade, different cut.
The snowplow trucks all have a tread that is modified for winter that wouldn't last at all in the summer.
At Bonneville they would be like stress risers in steel.

[Richard Thomason]

Actually, we have run siped tires during the summer also. It seemed to give both better mileage as far as fuel economy and longer life. Maybe it had to do with heat disapation or who knows what. Some rigs acted really funny in the handling department and others seemed to be better. I don't have a clue as to why.

[JackD]

Anything that causes the tread to squirm will shorten it's useful life and not contribute to fuel economy.
The difference in response to the siping treatment has more to do with the tire construction, tire pressure, and wheel size.
Radials are quite different than bias tires in their response to tread modifications.

[JackD]

Can you imagine a tire engineer reads this stuff ?
Well one of them called me to say that siping would void the manufactures warrantee but does work in limited applicationsbut and on the salt is not one of them.

[Harold Bettes]

Jack,
I could never figure out how a guy could go to cutting on high dollar tires. And after I have read of some of the values of the Bonneville tires.....WOW. Currently, I have all my Bonneville project tires protected as well as some of the documents in the Library of Congress. I would never have the courage to either "re groove" with a grooving iron or use a siping tool.

Besides, my wife won't let me near the carving knives, anyway.

Regards to All,
HB2

[JackD]

You must recall the very early lesson of not running with the scissors.