The Story Of The Fox Podium

June 24, 2025

During the creation of our feature on the new Fox Podium inverted single crown enduro fork, we spent some time with the Fox Factory team to learn all about it from the horse’s mouth. Sitting down with Ariel Lindsley, Fox’s Product Development and R&D engineer, we were treated to a deep dive into the development process.

Read below to find out what he had to say about the new and exciting Fox Podium fork.

What was the inspiration? Why an inverted fork?

Why did we all of a sudden decide to do an inverted fork, right? It really came down to one of our senior engineers, Bill Becker, doing a study on bushing pressures.
For model year 26, we put a big focus on reducing any kind of binding or any friction that builds up, then releases partway through the stroke. That is always something that translates through to the rider’s hands in a negative way, and we wanted to reduce that as much as possible. It’s one of the reasons we did our GlideCore air springs that we’ve come out with, which we don’t have to dive into yet on this question.

But he dove into studying the buildup of pressure on the bushings as you load the fork a lot, like fore and aft. The stanchion’s getting pushed harder into the bushing material, and that will cause some binding and some of that buildup of pressure and then release you get partway through the stroke.

The load increases to a point where the fork doesn’t want to slide as easily anymore, and then all of a sudden it breaks through, and that never really feels good to a rider. So he included inverted forks in his study of those bushing pressures. There were two key things to the inverted design that showed that the bushing pressure buildup was greatly reduced in an inverted fork design.

The first one, and the simplest one, is that we were able to spread the bushings out another 50 millimeters. In traditional forks, we’ve pushed that almost as far as we can get. They’re in a pretty good place, but to get 50 more millimeters is a huge gain in itself. The standard in a 38 is about 120mm. Now we’re at 170mm, which that’s a huge jump. We fight for millimeters in the rest of our forks to spread those out again.

But the second one was also that in a traditional fork, the distance from your axle to the top bushing never changes as the fork goes through the travel. And so as you increase loads, the lever arm is always the same length. In an inverted fork, your axle, as you compress the fork and inevitably put more load into the fork, gets closer to that bushing so that lever arm shortens, which is actually beneficial.

The harder you’re pushing into that fork, the shorter the lever arm that’s pushing that stanchion into the bushing gets. When he plotted those bushing pressures, you can see that with that overlap and that axle ratio changing, it’s a drastic decrease in bushing pressure buildup. That was the final thing that said, we need to build one of these and see how it goes.

Instead of having that stick-slip phenomenon and binding phenomenon, the fork is able to move all the time.

Now you can really tune in those regions where you may have been paying tuning sacrifices with the damping and stuff like that to help that issue.

One thing that’s really been standing out to me so far with the fork is that I’m not trying to bring comfort back in by reducing the amount of damping. What other factors are contributing to that consistent smoothness that I’ve been feeling so far?

I think that’s it. It’s that the fork doesn’t want to bind. I think for a lot of people, this fork is meant to be ridden hard, it’s not the lightest thing out there by any means. But when you ride hard, a lot of us, especially bigger riders like yourself and I, have to run a pretty firm fork. There’s just no way around it. You need that support when you’re riding down steep, chunky terrain.

Otherwise, you’re going out the front and nobody wants to do that. But by doing that, I think we pay some penalties of harshness and maybe not the most supple feeling fork on the little small stuff sometimes.

This fork allows us to have the support we need, use damping and use spring to hold us up like we need, but not pay as big a penalty for doing that over all the small bumps, chatter in your hands, even the big hits in our hands.

It’s important in forks because they’re one-to-one, right? It’s directly translated. Whatever happens there is directly translated through to your hands, and they’re not as strong as your legs. Any help we can get, we’ll take it.

What have you implemented to improve that torsional stiffness and make it a rideable, aggressive fork?

There’s always been a lot of drawbacks to the inverted forks that have been available…That was a big question for us when we started. We needed to make the fork torsionally stiff enough to steer good enough so that you don’t feel the negative effects…So we made a bunch of different tuning parameters and options in the chassis. So we had to set out to tune this chassis to be a good fork.

The big question came up, how stiff do we need it to be torsionally, and is there too stiff? We made a bunch of different upper tube options and thicknesses, different crowns, different lower legs. We even did different dropouts. We did a 15mm originally and then we made a 20. In testing, it seemed like a lot of the heavy options kept winning. We were a little bit like, “oh no, it’s getting heavier” …because the weight’s a thing, and it isn’t a light fork, but we let performance drive. Then we went on. When we moved to 20mm axle, 15 kind of got crossed off pretty early because it just didn’t have it. It wasn’t enough. You noticed it too much. So we got rid of that, and we focused on 20, which is fine. 20 by 110 is a standard. It’s not a proprietary thing.

We had a bunch of different stiffnesses of axles. The first round we did were aluminum axles just because they’re light. That was nice. We got to the stiffest aluminum option. We said, yeah, with that one’s the fork’s riding really good at this point…But that question still lingers, the stiffest option just won, so do we need to go stiffer?

So we came away from one of those test sessions asking “how do we make it stiffer?” We made a steel option that was just as stiff as the aluminum one that won out. We made some stiffer options in steel after that, and we rode those. We actually did find that we got to a point where there’s some magic in a little bit of torsional flex when the fork’s really stiff this way in fore-aft. We found a place at which some of the magic and some of that good stuff that you’re probably feeling just started to kind of fall apart….so we landed at where we are now. We tested in the lab to make sure everything’s safe. We think we found a pretty good sweet spot. That’s how we ended up there, by letting performance drive and testing in the blind.

I guess some people are going to be asking the question of, is there going to be a 180 mil travel option coming? And then, I guess, why maybe a 180 mil travel option didn’t become available to start with.

Obviously, this was a new venture for us, right?…there’s been a lot of headwind, let’s say, with inverted forks and torsional stiffness and weight…we knew we weren’t going to be lighter than a 38. So, we left 180 out to start somewhere and feel like we’re giving ourselves the best chance to find the sweet spot we did and to see what that looked like as far as weight, as far as ride quality. Leaving at 170 just felt a little easier. It was like, let’s not add too many challenges for this go.

I think now, being where we’re at, we could probably do some moving things around and get there and it would be fine. But we didn’t know when we started, right? And so, sometimes when you don’t know and you’ve got to figure it out, it’s easy to say, let’s cross this option off just to not make it harder than it has to be. Or not get to a place that’s good and be like, oh, it doesn’t work.

I think that’s really good that we did that. We found a good sweet spot, I think. And I think it’s playing out well for people when they’re riding it now. We had to start somewhere. So, I think that’s just why we didn’t do 180 right out of the gate. And, yeah, some people want it and ride 180 enduro forks and that’s cool. But we felt safe enough that 170 was going to cover a lot of people’s needs. That’s enough. So, we’ll start there.

Through this project, what are you most excited about and what are you most proud of?

I’m pretty excited about how the fork’s working. I think it’s giving people some performance that we hadn’t been able to deliver in a traditional package…you can keep riding high in its travel.

We can introduce more damping without it feeling like you’re getting harsh. And when we can use damping to control things and we’re not making sacrifices there to deal with other issues, you get better performance.

Damping is speed sensitive to how fast the fork’s moving in either direction. And you have way more control over that with valving than you do if you’re just dealing with some inherent friction and binding. So, we’re excited about that. I think that translates to people getting a lot smoother, more comfortable, fun riding fork with better traction. I’m excited for people to experience it.

I think as far as being proud of it, I think our team did a great job of overcoming some of the challenges that have been around in inverted forks. And I hope that people can get out there and ride it and maybe have their minds changed a little bit about that style design and that it can work. So I guess I’d be proud of our team that we actually confronted those challenges and did some really good stuff. Some real homework and some real testing to make it a viable option for people to ride an inverted fork that feels good, you know, and doesn’t have as many drawbacks as some of the ones that maybe have been put out in the past that we’ve probably all ridden a little bit. I think that’s neat.

It shows some real engineering prowess and I’m proud of those people. I’m kind of one of those people, but I kind of just get to ride all their hard work.