what's_new_bnr.gif - 14340 Bytes
gif_lib\home_btn.gif - 1337 Bytes

The Newest Items on the Site

gif_lib\aautobull1.gif - 358 BytesNew 2005 Car Specifications for the San Diego 500.

gif_lib\aautobull1.gif - 358 BytesAfew corrections and updates to the 4-lane track design

 

News from users and experiences to share

gif_lib\aautobull1.gif - 358 BytesYou can buy aluminum track plating directly from Beta Crafts. Its cheaper and they're the folks that designed it.

 

In November-December 1998 The BSA  supply system began to ship different pinewood derby kits to its distribution network..
After years of good quality kits coming from Beta Crafts in New Jersey there seems to be something different being delivered 
this year. For those that have been around a few years you'll remember prior to '92 there was good reason to have rules that 
permitted the sanding of the plastic wheels that came the box kits. Those wheels were 'out of round', had a molding seam around the 
center outside portion of the tread and had various plastic debris still hanging off the wheel. 

While the new wheels aren't really bad, many are not consistent. The worse part is that the axle holes in the wheels are not the same 
size between kits. Some folks are buying several kits to find what they regard as a "good" set of wheels. It isn't clear that there is a 
big difference in the wheel's performance but you don't want to mix them up on the same car. The racing officials need to be aware 
that there are differences in the kits, the racers aren't cheating.        

Another problem is the wood block. The axle cuts across the bottom of the block are sometimes out-of-square and the blocks 
are not always uniform in length, width or height. This means that the car can not track straight without bending the axles. For those 
units that prohibit the moving of the wheel location this can be a problem for the racer. Correcting the problem by re-cutting 
the same slot will make it too large for reliable wheel alignment and the axle must be cemented into place.         

The following table lists typical physical characteristics for the some of the recent BSA Grand Prix Derby wheels. Please 
understand that while these measurements were taken with very accurate equipment the molding production techniques and 
various molds used to produce the plastic wheels generate slightly different wheels. You can tell which mold cavity your 
wheel came from by reading the casting impression on the inside of most wheels. These mold cavities are not identical and 
neither are the wheels that come from them.        
While there are variations on the wheels produced these four groups represent the wheels that have been produced in the 
greatest volumes.


 1999_inside.JPG - 19250 Bytes Mvc-013f.jpg (33658 bytes)Mvc-014f.jpg (28898 bytes)Mvc-016f.jpg (31771 bytes)Mvc-015f.jpg (27811 bytes)      
Wheel
Characteristics
Older Wheel
C.M.I.
'98 Wheel Style
14-spoke
'99 Raised Letter
12-spoke
'99-02 Smooth Sided
12-spoke
Wheel Diameter 1.183"-1.187" 1.187"-1.189" 1.190"-1.197" 1.185"-1.194"
Skirt Thickness
(At Mid-Tread)
0.118" 0.090" 0.087" 0.091"
Tread Width 0.290" 0.285" 0.284" 0.275"
Axle Opening ID
0.100"
#39 Wire Size
0.099"
#39 Wire Size
0.089"
#43 Wire Size
0.092"
Between #42-#43
Inside Axle Hub OD 0.246" 0.250" 0.272" 0.275"
Axle Barrel Length 0.298" 0.272" 0.361" 0.353"
Wheel Mass (grams) 3.782 g 3.273 g 3.531 g 3.590 g
Supplied Axle OD 0.090" 0.089"-0.090" 0.089" 0.092"
Wheel Thickness
(Hub to side-wall)
0.415" 0.420" 0.435" 0.428"
Comments This wheel type
required more
work to make
competitive
Very clean
molding that
required little
work to roll
smoothly
Larger axle
contact area, more
"out-of-round"
Tread surface is tapered from
inside to outside 
gif_lib\home_btn.gif - 1337 Bytes

TOP of Page