MAXIMUM VELOCITY! ®
4081
4080-BSA Pinewood Derby Pro-Stock Matched Speed Wheels &
4094-BSA Speed Axles
3.3 Gram Wheels By DerbyWorx
BSA wheels are well designed, but unfortunately the wheels vary considerably from mold to mold. Most of the wheels are not perfectly round and the tread surface is not even.
These Pro-Stock Speed Wheels are official BSA wheels which are sorted by mold number, and then precision machined with a CNC (computerized) lathe for maximum performance. To provide you with an awesome set of wheels, we perform the following operations:
- The wheels are sorted by mold number, and any defective wheels are discarded.
- Wheel bores are reamed and bored perfectly round and smooth.
- Inner and outer hub faces are squared to ensure accurate mounting on the CNC lathe.
- The wheel tread is lathed with True Track to achieve a perfectly round wheel, a flat tread surface, and a slight radius on the edges to replicate the look of a stock BSA wheel.
- The inside wheel hub is lightly beveled to reduce contact with the car body.
Benefits
- Round and smooth wheels roll faster than standard wheels.
- Matched mold numbers ensures that the bore diameter and other wheel measurements are identical, maximizing performance.
- The molding mark on the tread is virtually removed, eliminating the 'bump'.
- The beveled hub reduces the braking that occurs when the wheel hub contacts the car body.
Usage
These Pro-Stock Matched Speed Wheels are used without any additional preparation. Just lubricate and race!
Important Note
The lathing operation removes a small amount of tread surface. The serrated edge is intact. The tread reduction is barely visible to the eye, but is measurable with a caliper. If your race restricts the use of lathed wheels, consider using our specialty tools and supplies to prepare a set of raw wheels.
Comparison Chart and Photos of Matched Speed Wheel Types
| Model | Trued
Tread | Coned
Hub | Trimmed
Edge | Reamed
Bore | Weight
Reduced |
| 4090/4091 |
Yes |
No |
No |
No |
No |
| 4080/4081 |
Yes |
Yes |
Yes |
Yes |
No |
| 4070/4071 |
Yes |
Yes |
Yes |
Yes |
Yes |
| 4060/4061 |
Yes |
Yes |
Yes |
Yes |
Yes |
Technical Information for 4080/4081 Wheels
- Wheel Diameter: 1.170 ± 0.001 (Raw Wheels: 1.184 to 1.199)
- Wheel Bore ID: 0.098 minimum
- Wheel Weight: 3.3 grams per wheel (Raw Wheels: 3.6 grams/wheel)
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