For Powersports Fans, It’s All About Ultimax® Belts


For Powersports Fans, It’s All About Ultimax® Belts

Timken makes all kinds of industrial belts, but our Ultimax brand is the most well-known by many end users. Why? Powersports. For more than 30 years, Ultimax has provided consumers the most advanced belt on the market for continuously variable transmission (CVT) drives. It’s what connects power to the ground for snowmobiles, all-terrain vehicles (ATVs), utility terrain vehicle (UTV) and side-by-sides.

We spoke to two experts on the Ultimax Belts team about what they do, why they do it, and why their friends are so jealous.

Bryce Curl, Powersports Specialist
Favorite Powersports Vehicle: Snowmobile
Location: Springfield, Missouri, U.S.A.
Quote: “Powersports technology is rapidly advancing. My goal is to continuously improve our product and stay ahead of the competition.”

Braden Hill, Powersports Application Engineer
Favorite Powersports Vehicle: All-Terrain
Location: Springfield, Missouri, U.S.A.
Quote: “Our job is to support the customer and develop the next best belt ever. That’s where our focus is, and where it will be.”

Q: What role does a belt play in a snowmobile or an ATV?

Hill: Powersport applications push 200+ horsepower, and the belt is what connects all that power to the ground. The belt sees very high temperatures and tension. CVT powersports is quite an abusive application for the belt, so there’s a lot of design that goes into being able to handle that. Every year, manufacturers push for bigger, more powerful vehicles, so every year we’re asked to build a belt that can pull more power and survive harsh conditions.

Q: Why has the powersports market grown so much in the past few years?

Curl: It’s about being outside. Sometimes it’s just about the only way to get to really out-of-the-way places. You might be able to hike up into the woods, but not everybody can do that. With snowmobiles or ATVs, more people can be exposed to the wilderness, to being outside. It’s also about being part of a family-friendly community and it’s just a great way to relax and enjoy the environment.

Hill: We were already seeing an increase in powersports events, racing competitions and recreational trail development. Then, the COVID-19 pandemic brought out even more demand. People want to get outside, ride and have fun.

Q: How did Ultimax become a belt of choice for powersports enthusiasts?

Curl: In the early days of powersports, the belt was the weakest link. People loved riding snowmobiles but struggled to find a belt that could last. Riders became very proficient in changing belts.

Development was done through trial and error. Engineers back then would design a variety of belts and field test on snowmobiles until they failed them all. They did that over and over again until they improved the belt. In 1988, the Ultimax brand was introduced. It featured aramid cord, and that was a game-changer.

Q: How does Ultimax remain a performance leader?

Hill: Today, we still do a million miles of field testing on snowmobile belts each year. We test for two main failure modes.

Flex fatigue failures usually happen with high-mileage touring sleds, where the belt is bending over a high frequency for a long time. To test for that, we stay on the trails and rack up miles.

Power capacity failures correspond to the tensile strength of the cord and the rubber compound’s ability to support the cord. To test for that, we take the sleds off-trail, up to the mountains where the snow is really deep, producing heavy loads on the belt.

In the lab, testing is focused on material development and accelerated bench testing of these failure modes.

Curl: It’s important to us to maintain the competitive nature of the brand — to be the hands-down leader in the market. This year, we will have put belts on hundreds of sleds, and we do the same for our ATV and UTV belts — riding through sand dunes, desert, mud and rock crawling. We go out and look for people who are riding the machines the hardest — try to find out what they’re doing and where they’re going. Then, we make it worse than that and test to that condition. 

Over a million miles of field testing data is gathered each year.

Q: What technologies make Ultimax belts stand out today?

Curl: The big thing is materials. First, it was the aramid cord, but we continue to work on different cord and ways to treat the cord. We’re also developing new rubber compounds that can handle more power, and we’re fine-tuning belt construction — how we layer all the materials together.

Hill: The jump from polyester to aramid cord significantly improved power capacity. Another big development was fiber loading of the rubber element. Today, finely chopped fibers are dispersed throughout the rubber compound, increasing its rigidity and ability to support the cord.

When we were acquired by Timken in 2015, we started testing friction. The side wall of the belt makes physical contact with the clutches, and that friction affects the design and the clutching setup of each application. New testing technology helps us optimize the relationship between the belt and the clutch in customer designs.

Q: How does your work on Ultimax contribute to the broader Timken® belts product line?

Hill: Powersports applications require the most technologically advanced rubber compounds and textiles in the power transmission world because of the sheer speed and power that they transfer to the ground. A machine’s responsiveness and behavior are highly dependent on how well the belt does its job.

When we make technological advancements, other Timken belts also benefit.  For example, we’re currently working on a materials adhesion process that we’ll implement in other belt applications that operate at similarly high speeds.

Powersports applications are hyper-sensitive to any inconsistency within the belt, so Ultimax quality control measures certainly carry over to improve power transmission products across the company.

Q: What’s the best part of working on the Ultimax Belts team?

Hill: I get to work on and develop a product in a field that I’m passionate about. I get to experience the fruits of my work and follow the progression myself — it’s not something that gets sent off somewhere, and I never see the difference. I can put on a new belt, go for a ride and feel the improvement.

Curl: I like the challenge. Because the machines are constantly evolving, it’s something new every day. I always like hearing back from customers. It gives me a lot of pride to hear how long a belt has lasted or how a customer grew up using Ultimax belts on their snowmobiles. It’s nice to be part of that community.

This is a dream job for me, as someone who grew up riding dirt bikes and four-wheelers. Days when we do field testing or we go out to the sand dunes, I like sending my friends a picture. “Tough day at the office.”


Timken offers a wide variety of belts for the most demanding markets and applications. Partner with us on your next design project.

Timken® is a registered trademark of The Timken Company and Ultimax® is a registered trademark of Timken SMO LLC.