2025 Rivian R1S: Underbody Upgrades and Engineering Improvements

The 2025 Rivian R1S has arrived with a host of engineering updates and improvements, particularly in its underbody design and components. This article provides a comprehensive analysis of these changes, comparing the new model to its predecessor and highlighting the significant upgrades Rivian has implemented.

Subframe and Suspension Updates

Cast Aluminum Subframe

One of the most notable changes in the 2025 Rivian R1S is the new cast aluminum subframe. This represents a significant departure from the previous model's design, which utilized numerous extrusions and stamped aluminum parts welded together. The new single-piece cast subframe offers several advantages:

• Reduced part count (from 25+ individual parts to mostly a single part)
• Improved manufacturing efficiency
• Better integration of attachment points for various components
• Potential weight savings

This change demonstrates Rivian's commitment to optimizing their production process and improving overall vehicle design. The move from extrusions to a cast subframe is indicative of Rivian's transition from a rapid prototyping mindset to a more mature, high-volume production strategy.

Suspension Components

While many suspension components remain unchanged, there are some notable updates:

• The lower control arms appear to be carried over from the previous model
• The knuckle has been redesigned, with material removed from the bottom interface
• Some pockets in the knuckle design have been fully opened up, likely for weight optimization

These changes suggest that Rivian has been able to refine their designs based on real-world data and durability testing, allowing them to remove excess material where it's not needed.

Active Hydraulic Air Suspension

The 2025 R1S retains Rivian's innovative dual-system suspension:

1. An active hydraulic system for modulating stiffness and damping characteristics
2. An air system for adjusting ride height

This combination allows for a wide range of suspension adjustability, catering to various driving conditions and preferences.

Powertrain Updates

New Electric Drive Unit

The 2025 R1S features Rivian's new in-house designed electric drive unit, replacing the previously sourced Bosch setup. This change represents a significant investment in Rivian's vertical integration strategy and could lead to improved performance and efficiency.

Motor Mounting Strategy

The new motor mounting design incorporates:

• A split joint attaching to the motor mount
• Elastomeric mounts suspending the electric drive module (EDM)

This setup appears to be designed for improved crash performance, potentially allowing the cradle to decouple from the powertrain in a frontal impact, maximizing crush space and limiting powertrain intrusion into the passenger compartment.

Battery Pack and Underbody Protection

Battery Pack Changes

The battery pack has seen significant updates in the 2025 model:

• The rear face of the battery pack is now a large single casting
• This replaces the previous extruded face with multiple machining operations
• Improved sealing strategy between the battery pack and the casting
• Potential for better integration of connectors, vents, and coolant lines

These changes likely result in improved manufacturing efficiency, better sealing, and potentially enhanced structural integrity of the battery pack.

Underbody Protection

The underbody protection strategy has evolved:

• Previous aluminum extrusions have been replaced with what appears to be an overmolded aluminum or composite shield
• This change could offer weight savings while maintaining necessary protection for off-road use

Rear Suspension and Cradle

The rear suspension setup remains largely unchanged:

• Multi-link suspension with aluminum control arms
• Separate air springs and shock absorbers

Interestingly, the rear cradle appears to be carried over from the previous generation, despite the new motor design. This demonstrates Rivian's ability to integrate new powertrain components without requiring a complete redesign of surrounding structures.

Noise, Vibration, and Harshness (NVH) Improvements

Rivian has made changes to their NVH strategy:

• The previous PUR and VH insulator has been replaced with a multi-layer solution
• A foam inner layer is now combined with a hard TPO outer shell
• This change could provide better protection against dirt and debris while potentially improving noise insulation across a broader frequency range

Manufacturing and Design Philosophy

The changes observed in the 2025 Rivian R1S reflect a shift in the company's manufacturing and design philosophy:

• Moving from rapid prototyping techniques (like extrusions) to more optimized, high-volume production methods (like large castings)
• Refining designs based on real-world data and durability testing
• Balancing the need for weight savings with structural integrity and protection
• Improving manufacturing efficiency and reducing part counts where possible

Implications for Rivian's Future

These updates to the R1S demonstrate Rivian's commitment to continuous improvement and their ability to quickly implement significant changes. The willingness to invest in new tooling and manufacturing processes for key components suggests a long-term vision for the platform.

The speed at which these changes have been implemented is particularly impressive, especially considering the complexity of electric vehicle architectures. This agility could serve Rivian well in the highly competitive EV market, allowing them to rapidly iterate and improve their products.

Conclusion

The 2025 Rivian R1S showcases a range of engineering improvements that go beyond mere cosmetic updates. From the new cast aluminum subframe to the redesigned battery pack interface, these changes reflect a maturing product and company. Rivian has demonstrated their ability to optimize their designs for high-volume production while maintaining the innovative features that set their vehicles apart.

As the electric vehicle market continues to evolve, Rivian's willingness to make significant engineering changes and investments positions them well for future growth and competition. The 2025 R1S is not just an update, but a testament to Rivian's engineering prowess and commitment to continuous improvement.

For potential buyers and EV enthusiasts, these changes suggest that the 2025 Rivian R1S will offer improved manufacturing quality, potentially better performance, and a more refined overall package. It will be interesting to see how these underbody improvements translate to the driving experience and long-term reliability of the vehicle.

As Rivian continues to refine their designs and manufacturing processes, we can expect to see further innovations and improvements in future models. The EV market is rapidly evolving, and Rivian's ability to implement significant engineering changes quickly will be crucial to their long-term success in this competitive landscape.

Article created from: https://youtu.be/HbP_LEVkuLA?feature=shared