Sirris Suspension: The Next Evolution in eMoto Performance Suspension

A New Era in Electric Dirt Bike Suspension

When it comes to high-performance electric dirt bikes in the ECR stable, the Surron Ultra Bee is a bike we just can’t seem to stay away from. It may not be the fastest or the biggest, but it’s often the most fun—and that’s why it’s been such a popular machine.

Today, we’re making a bold statement: this is the best Surron Ultra Bee that exists. The reason? Two key components—the bike is equipped with the new Sirris F43 Fork and the Sirris R46 Shock. These suspension upgrades have completely transformed our ECR Ultra Bee into one of, if not the, favorite bike in our stable.

So, what is Sirris Suspension? We’re glad you asked. They’re a new player on the scene, responsible for a massive leap forward in suspension technology, specifically engineered for electric dirt bikes like the Surron Ultra Bee and adaptable to other high-performance bikes like the Dust Moto.

The talented folks at Sirris bring decades of high-end suspension experience to the table. With backgrounds from Fox Suspension and Ohlins, this team is no stranger to premium powersports suspension. Having worked side by side with them, we’re beyond stoked to see another reputable brand entering the e-moto scene. And we’d be lying if we said we weren’t chomping at the bit to share this news.

The much-anticipated F43 fork and R46 shock tailored for the Surron Ultra Bee will be available in Fall 2024 and you can pre-order it here on ECR Parts.

Extensive Testing and Real-World Application

Our excitement for Sirris Suspension is backed by extensive testing and real-world experience. We’ve logged significant seat time on the Sirris-equipped Ultra Bee, including a demanding 60-mile big mountain enduro race and numerous hours tackling challenging terrain in Colorado. The “Test Pilot Program” stamp on the fork and shock reflects the thorough vetting process used to gather feedback and ensure these components are optimized for peak performance before they reach your doorstep. 

Sirris F43 Surron Ultra Bee Fork

The Sirris F43 Fork stands out as a closed cartridge, spring design fork that seamlessly integrates with the Surron Ultra Bee’s OEM setup. This includes compatibility with the display, fender, and brake caliper, making it a true bolt-up system that requires no additional modifications. The fork’s 43mm stanchions and robust upper fork tubes provide a significant upgrade to the front end, enhancing stability and stoutness without compromising the bike’s turning radius.

With 246mm of travel—6mm more than the stock setup—the F43 Fork offers additional travel, which is particularly beneficial during aggressive riding. Furthermore, the hydraulic bump stop feature ensures smooth handling of even the most forceful impacts at maximum stroke. These attributes combine to create a fork that not only enhances performance but also contributes to the rider’s confidence on challenging terrain.

It’s not all about hard-charging either, this fork is highly tunable to get an extremely plush set up for riders who are seeking comfort over performance.

• True Symmetrical Closed Cartridge: This design ensures balanced load distribution and consistent, race-ready performance, no matter how hard you push. The closed cartridge system is engineered to resist fade, maintaining predictable handling even after countless laps.
• Hydraulic Bump Stop: Experience soft landings at maximum stroke, even on the most aggressive impacts, thanks to the hydraulic bump stop.
• Dual Oil Circuits: Separate lubrication and damping oils allow for optimized damping performance without compromise.
• High-Quality Materials: Crafted from 7000 series aluminum with Type 3 hard anodizing for maximum strength and scratch resistance. The hard chrome stanchions and wrap-around guards ensure your fork performs like new for longer.
• Ultimate Suspension Tuning: Fully tunable valving on compression and rebound, with spring rates matched to your weight and riding type. This allows you to adapt your suspension setup for different rides, enhancing your overall experience.
• Plug-and-Play Installation: The F43 fork is a direct swap for the stock Ultra Bee fork, with no modifications or additional parts needed. It comes equipped with a dust seal and headset bearing pre-installed on the steerer tube for a quick and easy install. The triple clamps and guards are designed to fit directly with the Ultra Bee fairing and cable routing.
• Lightweight: Each leg weighs only 8.8 lbs (4 kg) in the standard configuration, making it a powerful yet lightweight upgrade.

F43 Fork Specifications

• Fork Diameter: 43mm USD
• Length: 856mm
• Travel: 246mm
• Offset: 25mm
• Compatibility: Surron Ultra Bee

Sirris R46 Surron Ultra Bee Shock

Complementing the F43 Fork is the Sirris R46 Shock, which features a 46mm piston and a comprehensive range of adjustments. Riders can fine-tune High-Speed Compression (HSC), Low-Speed Compression (LSC), and Low-Speed Rebound (LSR) to adjust their setup on evolving terrain. With spring rates available for a wide range of rider weights, the R46 Shock offers unparalleled customization, allowing for precise adjustments that optimize the bike’s performance across various terrains.

One of the standout features of the R46 Shock is its adaptability. Whether you’re a hard charger, looking for plush comfort or require a setup for heavier loads, the shock can be tailored to meet your needs. This level of precision ensures that the suspension system enhances the overall riding experience, providing both comfort and control in demanding situations.

• Exceptional Responsiveness: Like the F43 fork, the R46 shock offers fully tunable valving on compression and rebound, with spring rates tailored to your weight and riding style. This allows you to adapt your suspension setup for different types of rides, ensuring an unparalleled riding experience.
• Dual Speed Compression (DSC): This feature provides a broad adjustment range, allowing you to fine-tune both high-speed and low-speed circuits independently for superior control.
• Customizable: The R46 shock is tunable to any rider style and condition, with high-tensile steel spring rate options that support weights up to 300 lbs (135 kg).
• Built to Last: The R46 shock is built with durability in mind, featuring a Type 3 hard-anodized body cap, reservoir, end cap, spring hardware, and clevis. The induction heat-treated, hard chrome hollow shaft ensures that your rear shock will look and perform like new, even after thousands of miles.
• Easy Rebuilds: The fully serviceable design ensures that rebuilds and custom tuning are straightforward and hassle-free.
• Direct Swap: The R46 shock is easy to install, with a 320 mm length and 85 mm stroke that bolts directly onto a stock Ultra Bee.
• Lightweight: Weighing only 3.9 lbs (1.76 kg) plus the spring, the R46 shock is a lightweight yet powerful addition to your bike’s suspension system.

R46 Shock Specifications

Stay tuned for more updates as we get ready to put this fork and shock in the hands of more Ultra Bee riders. Whether you’re riding the Ultra Bee or have your heart set on the upcoming Dust Moto, Sirris is an upgrade worth looking into.