Description
BSA pinewood derby 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.
Our Ultralight Speed Wheels are official BSA wheels which are sorted by mold number, and then precision machined to tight tolerances with a HAAS CNC (computerized) lathe using proprietary fixtures and tooling. The precision of this machining cannot be duplicated on hobby lathes.
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.
- Outer hub faces are coned to minimize contact with the axle head
- 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 inner edge is polished to reduce friction when rail-riding.
- The weight of the wheel is reduced by removing plastic from the underside of the wheel tread.
If you would like to order wheels with a particular mold number, Click Here.
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 weight reduction provides a faster start, and improves the balance of the wheel for a smoother ride.
Usage
The Ultralight Matched Speed Wheels are used without any additional preparation. Optionally polish the bore with Bore Polish, then 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 Outer 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 4070/4071 Wheels
Wheel Diameter: 1.170 ± 0.005 (Raw Wheels: 1.182 to 1.185)
Wheel Bore ID: 0.098 minimum
Wheel Weight: 1.6 grams per wheel (Raw Wheels: 2.7 grams/wheel)
