Let’s Talk Wheels…
The BSA has retired the old 1999 wheel molds and released the NEW 2009 WHEEL MOLDS for the Official Pinewood Derby wheels. It seems they took the opportunity to make some major changes to the wheel design. Let’s look at a few of the new 2009 mold features for comparison the the 1999 mold features.
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1999 Wheel Mold
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2009 Wheel Mold
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Mold Sprue Mark:
(1mark) Outer Tread Surface
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Mold Sprue Mark:
3 marks) Inner Rim Face
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Bore Diameter:
.093″ – .098″
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Bore Diameter:
.094″ – .098″
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Rotational Inertia:
5.16g/cm2
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Rotational Inertia:
3.66g/cm2
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Wheel Diameter:
1.187″ – 1.192″
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Wheel Diameter:
1.184″ – 1.187″
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Outer Hub Face:
Single Step Recess
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Outer Hub Face:
Double Step Recess
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Clean Bore
for the most part…
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Deformed Bore:
“Bore Squish” Larger in the center, smaller on the ends. How’d they mold that? Had to have been soft when they ejected the part.
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As you can see. The “out-of-box” wheels specifications are quite different.
I cannot, in good faith, state that two wheels with the physical differences shown above would have equal performance characteristics. Only after some serious modifications to correct for the imbalance in specifications can the performance be deemed, at least, comparable.
Many are down playing the new design as “equal” or “no distinct advantage or disadvantage to one wheel over the other“. The only reason I can see for these statements would be to for the purpose of clearing out old inventory.
One thing that has remained the same – matching all of the mold numbers in a set of wheels is still no guarantee of perfect match. The hub bore sizes vary in diameter as well as the taper of the bore. Even within the same mold number!
My hopes for the new mold is to significantly reduce the number of rejects. That would certainly help now that we only get 4 wheels per set rather than the usual 5.
VERY IMPORTANT NOTE: Some will boast about championships won with their “special” wheels. Wheels alone do not win races. Even the new BSA wheel design, with it’s pros and cons, is but one of many interdependent measure that will affect the performance of your car. “Doc” Jobe offers a Virtual Racing Program 
that lets you see how those seamingly insignificant tweaks can affect the overall performance of a car. Don’t obsess over one measure. Learn how to make all of them work together.
“Opportunity is missed by most people because it is dressed in overalls and looks like work.”
—Thomas Alva Edison
There’s no mass production line here at WinDerby. I, personally, machine each and every wheel, one at a time, with attention paid to detail and quality.
Here are just a few of the steps that I take with every single one of the wheels I prepare:
First, I hand select the best wheels and sort them into matched sets. This helps to make sure the finished set can be machined with the same set up for uniformity.
The matched sets are then lightly lathed round and concentric to the wheel bore. The tread edge is left in tact (except for “V” cut). I polish every wheel by hand with my special blend of GM. No mass production here.
I ream the hub bores to remove the taper and make the bore sizes equal (very important).Then I polish the inside of the bore until it shines like a mirror. The inner rim is trimmed square and finished with a radius. I square the hub face and give it a shine with my GM for the ultimate smooth and polished surface both inside and out.
After a final inspection, everything is packaged and protected for shipping. I take a lot of pride in providing the best BSA wheels on the market. My quality and craftsmanship speak for itself.
