15 Inch Bias Ply Slicks

16 Inch Bias Ply Slicks

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Item #             Size                       Application      Tread       Dia       Rim              Price

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Bias Ply Rain Tires
All bias ply rain tires use tread pattern B. 
See diagram below.

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Item #             Size                       Application      Tread       Dia       Rim              Price

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    #44125           19.5x6.5-10            F500             6.2         19.7       6-8"          $165.95

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    #44140           20X6.5-13            FF, FM, FC,       6.2         20.7      6-7.5"       $197.95
                                                             S2, DSR

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    #44150           20X7.5-13              FA, CSR          7.4         20.6       7-8"         

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    #44165           20X8.0-13             FP, GP, HP,      8.0         20.5         6"          $199.95
                                                             GT4, GT5

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    #44180           20X9.0-13           FA, CSR, DSR     9.7         20.6       10"         $217.95

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    #44185           21X6.5-13             FF, FM, FC,       6.7          21.2        6-8"      
                                                              S2, DSR

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    #44195           21.5X7.5-13         FE, SCCA SR     7.5          21.4         8'          $199.95

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    #44217           22X9.0-13            FE, SCCA SR,     8.5          22.9   8.5-10"     $215.95
                                                             FC, FM, FA,
                                                              CSR, DSR

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    #44220           22.5X7.5-13                   FF             7.5          22.8      5.5"      

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    #43565           23.5X13.0R-13      FA           12.9       23.5       14-15"

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    #43570            23X9.5R-15           FA             9.4       22.9         10"                 $321.95

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    #43585            23.5X13.0R-15     FA            13.0      23.0         14"                 

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    #43655            23.5X11.0R-16    GT2          10.6      23.6        10"

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    #43660             23.5X12.0R-16   GT2          12.1      23.5         12"                 $344.95

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    #43665              25.5X12.0R-16   GT2         12.4      25.6         12"               

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    #43671              25.5X12.5R-16   GT1         12.4     25.8         12"
                                C2000

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    #43676               25.5X14.0R-16  GT1         13.6      25.7        12"                 $372.95
                                 C2000

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    #43681               27X13.0R-16   GT1           13.0      27.3         13"                $360.95
                                 C2000

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    #43691               28X14.0R-16   GT1           13.9      28.2         13"                $388.95
                                 C2000

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The compounding of rubber for our race tires seems like the black art of an alchemist to some.  It is difficult to tell the difference in potential performance  between two tires just by looking and sometimes even by the "fingernail in the rubber" method.  We all know that softer rubber makes for sticky tires but the methods by which we can maximize the life of those soft tires is not as well understood.

A group of chemicals known as plasticizers is one ingredient of race tire rubber as well as carbon black which adds toughness and gives the rubber its black color.  A new tire has a coating of mold release which coats the outer surface sealing in the plasticizers.  A new tire will remain soft quite a long time as long as long as the mold release is not removed.  As soon as a tire is scrubbed in, however, the protective coating is abraded away and the plasticizers begin to evaporate and oxidize.  As that happens, the rubber begins to harden.

Three factors affect the rate at which a tire hardens:  heat, ultra-violet light and oxygen.  The presence of any of these increases the rate of rubber hardening.  On the track, all three are present.  A tire being run hard will sometimes reach 350 degrees momentarily in a turn.  The tire has air passing across it at over 100 mph and races are most often run in the sun. 

Race tires are one of the largest budget items for any racer.   Unfortunately, it is a fact of the racer's life that the softer the rubber, the shorter the tire's lifespan.  This is because softer rubber compounds contain more plasticizers.  There are some things you can do, however, to maximize the time that a tire will remain usable regardless of the compound.  Taking these precautions can lengthen tire life and reduce the cost of your racing. 

1.  First, keep your tires out of the sun when they are not in use.  Don't store your spares on a rack on the trailer.  Instead, put them in black garbage bags (if they are small enough to fit) and keep them in your garage or shop.  This is a good plan for the tires still mounted on your car, too.  While you are prepping it between races, pull the wheels and bag the tires to keep them out of the ultraviolet light.

2.  You may have to finish the "Honey Do" list before you can use the second method to keep your tires soft.  Since heat accelerates the evaporation and oxidation of the plasticizers, keeping the tires cool will also prolong their life.  If you have a spare bedroom or some unused spot inside your home, keeping the bagged tires in the air conditioned space will lengthen their life.  Be aware, though, that it may shorten your marriage!

3.  The third method is even more difficult to use.  If you can devise a way to keep oxygen away from the rubber, your tires will last longer, too.  Storing your tires in a hermetically sealed container filled with an inert gas will make them last almost indefinitely.  Garbage bags are not ideal for this purpose and I don't know of any affordable container which is.  For a short period, though, it is possible to bag tires and then use a vacuum to suck the air from the bag.  Use a nitrogen or argon bottle to add an inert gas until the interior pressure equals atmospheric outside the bag.  Then tie the top securely.  In this way the gas will tend to remain in the bag even if it is not perfectly sealed.  It's not a perfect solution but for short periods, it will help keep the rubber soft.

The grip of used race tires will begin to diminish as soon as you load the car on the trailer.  Without using any of these methods it will continue.  After only a month or two, the tires will be  two or three seconds slower.  After three or four months, they will be scary. We put on a fresh set for each race, usually on Saturday morning, using the tires from the previous race for Friday's practice.  If we go more than a month or two between races, we might mount new ones during the day on Friday.  Practice or testing on tires which make the car slide around is a waste of time and money.

If you have been running on the same tires for several races, you have probably gotten used to the way your car handles, but that is not the way it is designed to work.  Even before we began to sell Hoosiers, we had adopted the philosophy that fresh tires are an insurance policy.  Spins and off course excursions are much less frequent on good tires and crash damage always costs more than a set of tires.   On old tires you are fighting to control the car, possibly thinking you need to improve your driving. It is amazing how much your driving will improve when you have some grip! 

Use as many of the above methods as are practical for your situation  to maximize the life of your tires.  When they no longer stick as well as they should, mount a fresh set.  You'll be faster, enjoy your racing more and you may save money on fiberglass, too!