Derby Tech - September, 1985

by James H. McElhiney

Every year there is concern with lane equality. To understand why there is a problem, let's look at the construction of the hill and the effects of sun and shade on its surface.

Akron today with asphalt surface


Akron's hill is unique and unable to be duplicated because of the way it was built. The base ground was a combination of fill and solid ground that was shaved from the bank, next to the track. Over this base, concrete was poured with expansion joints over 40 feet. These joints were made of a tar substance very sensitive to heat expansion. Weather in Akron requires this type of construction. As years passed, the concrete was covered with blacktop and the cracks in today's surface are a result of the expansion joints beneath.

Akron in the 30's with original concrete surface


The lanes can be calibrated "equal" for a selected time of day, but they will not stay equal for a period longer than 1/2 hour. The reason is the underlying expansion joints. As the sun heats the concrete it expands, forcing the expansion joints to mushroom upward thus forcing the blacktop to rise at these points to form what I call mountains. The hammer noise you hear when cars are racing is caused by the wheels hitting these "mountains". Even with this condition, race times on hot days will be faster because heat on the rubber gains more than is lost by climbing mountains. If this condition was uniform from lane to lane there would be no problem. Sad to say, this is not the case. Lane 3 has the most, Lane 1 next and Lane 2 the least. Lane 2 is more stable because trucks were driven over it for years and seemed to compact the base somewhat.

The relationship between the lanes will vary considerably during the day, no matter what time of day the calibrations were set. Lane 3 will gain in relation to the others as the day becomes later, and the entire track cools. Lane 2 will become slower in relation to Lanes 1 and 3 because Lane 2 has fewer expansion joints (mountains) , that smooth out, and do not allow it to gain as much. Lane 1 becomes relatively faster than Lane 2 for the same reason. An effort has been made to smooth the mountains by heating and pressing down the blacktop. If anything, this has compounded the problem because, dips will be formed on cooler days. Since this practice has been used, obtaining an even calibration to start with has become even harder.


Two important factors in calibration are the cars. A fast set of cars will react very much faster to plate changes than the slower set. If calibration is done with slow (28 sec.) cars and the race is with fast (27 sec.) cars, calibration is never even, so heat changes are amplified.


There have been many solutions presented for this problem. They range from moving the race to photo or timer swap, to doing nothing at all. The mountain effect will be reduced if the race is run after 8:00 PM. These are my observations. A close look at heat wins and lanes, and the time they ran, may show you the same thing. Good luck!

Editor Comments and Worthwhile Raceday Tips:

This excellent article, written by Mr. McElhiney is a reprint, although not printed in its entirety.

Mr. McElhiney is correct in that, the lanes will be more consistently equal if the race is run after 8:00 PM., or if the All-American would go to a photo, or timer swap.

My personal feelings are that the lanes, unequal as they are, is an asset to the race. This lane inequity insures that you need a little luck to win. It also broadens the number of possible winners, instead of the very few that have the resources and knowledge to build the top quality cars. These same few individuals would dominate the race year after year. The All-American as the lanes are, gives more contestants a chance to become a World Champion.

I had the opportunity to talk with George Kitchen last year about the lanes at Akron, and asked him for his observations. He agreed basically with what Mr. McElhiney has stated, but with some additional comments. Mr. Kitchen has observed many years of trying to equalize these lanes. He stated emphatically, that if it rains after the lanes are equal, Lane 1 will slow down by over a half a car length, in relation to the other lanes. I checked this out, and was surprised with the accuracy of his statements. For the last three years it has rained during the All-American race. Lane 1 had in fact slowed down immediately after the rain, and the resumption of the race.

Each of the starting plates at Akron have a different transition angle to the track surface. This is due to the raising and lowering of the plates to equalize the lanes. Different cars with different weight distribution, and/or wheelbases, will react differently while racing in the same lane. This is the case with all starting ramps, while Akron's type of starting ramp is the most consistent of all types of ramps.

These transition angles may be determined by taking a straight edge, and lay it flat on the starting plate, with the straight edge extending 18 inches in front of the plate. Measure the difference between the bottom of the straight edge, and the track surface. You will be very surprised at these large differences.

Hotter temperatures increase the the resiliency of the band of rubber on the wheels, allowing them to roll with much less drag, thereby increasing the speed of the racer.

The Z-glass wheels now used at the All-American, are much less susceptible to temperature changes than are the older steel wheels. This in effect, narrows the difference in lanes in regard to speed. The older steel wheels react to temperature approximately four times more, than do the new Z-glass wheels.

The ideal situation is to have your wheels as hot as possible while racing. This can be accomplished by keeping your wheels in the Sun as much as possible. Don't stand next to your racer and have your shadow shade the wheels. Position your racer in such a manner that keeps the car body's shadow off your wheels. The asphalt temperature is much hotter than the ambient air temperature. Therefore, you should have the wheels on the asphalt about 15 minutes prior to your race, rolling your racer slowly, back and forth, while keeping it in the sun. While rolling, have the wheels make at least one complete revolution, to heat the entire rubber tread.

Drive on the hottest part of the track. As the day wears on, some parts of the track may become shaded, and unshaded. Ninety nine percent of the time, more can be gained by driving on the hot spots, than by driving in the shade, to take advantage of any hill slope. Wheel temperature is much more important!

If you weigh your car before each heat, get this procedure completed as soon as possible, and get your wheels back on the hot asphalt. Also keep your wheels on the hotter asphalt as long as permissible, before loading it on the cooler starting ramp. This procedure has many times been the difference between winning and losing.

Return to the Derby Tech Page