FSAE Batwing Steel Tripod Inserts — 20T

Steel roller tracks for compact aluminum wheel hubs.

TRE Batwing Inserts provide steel running surfaces for our standard 20-tooth FSAE tripod inside a custom aluminum wheel hub. The contoured profile packages the steel around the tripod tracks, allowing teams to retain a compact bearing diameter while keeping the rollers running against steel.

Designed for the TRE 02002011 20T tripod, Batwing Inserts allow an integrated hub layout with a 70 mm bearing journal, or a 65 mm journal with a thinner surrounding aluminum structure. This provides a smaller radial package than our conventional circular steel inserts.

Steel at the roller contact. Aluminum for the surrounding hub structure.

Developed From a Real Team Problem

Batwing Inserts began as a way to recover a team’s existing wheel hubs after the aluminum tripod tracks had rolled in and deformed in service. Machining the worn tracks to accept steel inserts offered a way to extend the useful life of hubs that had already required substantial design and manufacturing effort.

That repair solution became a product teams can incorporate from the beginning. New hubs can now be designed around the Batwing profile, combining steel roller tracks with the packaging flexibility of a custom aluminum hub.

Compact Packaging for the Standard 20T Tripod

An integrated tripod wheel hub puts the outboard CV joint and wheel-bearing support into the same component. The space required for the tripod tracks directly affects the available hub wall thickness and bearing diameter.

The Batwing profile reduces the radial space needed for steel inserts compared with our circular insert design. This gives teams more room to develop a compact wheel end around the standard TRE 20T drivetrain.

Key benefits include:

• Steel running surfaces: The tripod rollers contact steel instead of running directly on the aluminum hub.
• Compact bearing packaging: Accommodates a 70 mm bearing journal, with 65 mm possible in a thinner-wall design.
• Custom hub integration: Teams retain control of their wheel interface, brake mounting, bearing arrangement, and upright layout.
• New-build or retrofit applications: Design the inserts into a new hub or evaluate their use in a suitable existing hub.

Design the Hub Around the Inserts

Bearing diameter is a packaging choice within the complete wheel-end design. A 65 mm journal leaves less aluminum around the insert pockets than a 70 mm journal, so the surrounding structure must be evaluated for the team’s loads, material, geometry, and fatigue requirements.

The inserts provide the roller contact surfaces; the aluminum hub must support them and carry the loads into the wheel and bearings. Pocket geometry, insert fit and retention, remaining wall thickness, tripod plunge, and articulation all need to be considered together.

For an existing hub, suitability depends on its condition and the material remaining after machining. Contact TRE before modifying worn hubs to determine whether a Batwing conversion is practical.

Bearing sizes above refer to bearing bore / hub journal diameter, not bearing outside diameter.

Compatibility and Design Support

Designed for the TRE FSAE 20T Tripod, part number 02002011, and custom aluminum hubs machined to accept the Batwing profile.

Contact TRE for design reviews, DFM support, and potential custom manufacturing of your hub designs.

Example CAD for machining your housing

Example housing shows required 2D path and full pocket.  Details of bottom fillets, etc are shown for example, with the concave bottom to interface with TRE axle snubbers on the plunging system.  

Sold individually, 3 are needed for a complete housing.