[Shotimes] Tire Siping

[Robert Bruce]

All dirt track racers know how to cut a tire properly.  It is done to get a
fresh, sharp tread.  Dirt tracks are normally made of clay.  The top layer
is usually wet and can be quite slippery.  A fresh cut tread will dig in
past the slippery layer and grip on the drier material underneath.  Sipes
are more narrow that grooves and can even be as narrow as a single knife
edge slice.  They provide grip on damp surfaces while not giving up much
surface area of the tire contact patch.

Also realize a good quality dirt track tire is real soft.  It may only be
good for two or three race weekends before it is worn out.  A race weekend
on a typical dirt track could be about 10 laps for warm-up/practice, 10 lap
heat race, 15 lap consi (If you didn't qualify for the main race through the
heat race) and finally a 30 lap or so main event.  If you are racing on a
1/3 mile track (typical), then you on get about 20 miles per weekend.  That
means tire life may only be expected to be 40 - 60 miles.

AFAIK, adding extra sipes are pretty much useless on pavement tires.  As Don
indicated, they will just build heat in the tire and accelerate tread wear.

Robert Bruce
93 atx


-----Original Message-----
From: shotimes-admin@autox.team.net
[mailto:shotimes-admin@autox.team.net]On Behalf Of Carl Prochilo
Sent: Thursday, April 01, 2004 11:03 AM
To: Donald Mallinson
Cc: shotimes@autox.team.net
Subject: Re: [Shotimes] Tire Siping


Good point, I should have clarified that my conversation with
Discount Tire was for an application of a high performance summer
tire to be used here in South Florida.  If you were worried about
driving in snow or dirt, forget this note.
--
Cheers,
Carl Prochilo
1992 Ultra Red Crimson

Donald Mallinson said:
> Carl,
>
> Just to be sure, I think the original comment was about
> putting the sipes (cuts) in a tire for traction in summer?
> If so, then more cuts, grooves etc is bad for both traction
> and heat.
>
> Then when you start adding in the realities of street
> driving...rain, snow ice, then the rules change.
>
> For standing water, more fairly big grooves is a good thing.
>
> Then for snow, ice, you want LOTS of small sipes, grooves
> and a squirmy tread is actually a good thing.  The tread
> movement allows the tread to throw off packing in snow/ice,
> and more edges equal better traction.
>
> As with anything, life is a series of compromises.  Only on
> a totally dry day at a smooth race track is a slick good,
> then the compromises start!  :)
>
> Don Mallinson
>
> Carl Prochilo wrote:
>> Ken,  I heard the same thing when I was in chat session with one
>> of
>> the people at Discount Tire.  The more grooves in the tire, the
>> less
>> structural strength you have in the tread, the less traction you
>> have.
>>
>> So the correct answer is buy the tire right the first time.
>>
>> BTW, these Nitto NT 555s are pretty neat.  I haven't fully tested
>> the limits of adherence with the new setup, but yesterday when I
>> was
>> coming back from Miami with my family in the car, I did one of the
>> off-ramps at 60 MPH and the car felt really planted and secure.
>> Like someone said, "on rails".  I like.
> _______________________________________________
> Shotimes mailing list
> Shotimes@autox.team.net
> http://www.team.net/mailman/listinfo/shotimes
_______________________________________________
Shotimes mailing list
Shotimes@autox.team.net
http://www.team.net/mailman/listinfo/shotimes