Interview: Formula's Suspension Engineer, Luca Rossi

If you only look at Formula through the lens of mountain biking, then their decision to start making suspension nearly a decade ago would seem like a strange one. Yet when you pull the lens back a little and realise that they have been making suspension for motorbikes for many years now it starts to make for more sense. When you then appreciate that they have been making suspension for the likes of Honda for many years the more appropriate questions seems to be why did it take them so long? Driving their push into mountain bike suspension is Luca Rossi, their suspension engineer. With a background in motorcycle racing, he brings a very different perspective to their products which in many cases take a different approach to the more established players on the market.

Editor’s note: This interview was recorded (in Italian) in early 2018 - but between the improvements in transcription technology and the extra time the pandemic has provided it is only now we are able to finally publish it.

How did you end up working at Formula?

I'm not here because I have a passion for bikes, I am here because of my experience working with suspension. I was working for another company, Paioli [editors note: an Italian motorcycle suspension manufacturer], I was there for five years. I started in the technical office then moved onto research and development and racing. I developed a suspension fork for 125cc GP racing in 2008, 2009. We had Andrea Iannone racing for us, but we didn't give it to him when he was young. I did a lot of years working on Supermotards with them - an Aprillia with my suspension won the world championship one year.

Did you study at university?

I studied mechanical engineering at Florence university - I did my industry placement at Ducati, I was working on steering testing and the fork. But I always had a passion for suspension as I always loved riding motos and that was what I wanted to work on, that was my passion. This stood me well for working on bikes as the products are quite similar.

You have said that mountain biking is the sport where the suspension makes the greatest difference.

Yes, that's something I discovered. I thought that with bikes the suspension counted for less, that the rider could just pedal. Instead I discovered a world where even in the case of low-level users they understand a lot more about what is going on and demand more from their suspension.

Which year did you join Formula and was the plan always to make a mountain bike fork?

2010, I was supposed to do both. When I started I made a pit bike and trials fork and began working on a mountain bike fork in parallel, but it turned out to be a longer process to develop it because it's a completely different project, you're using different materials, it has to be a lot lighter and you need to have a lockout. That doesn't exist for motos. It's a limitation with how space you have and the pressure inside the cartridge. It took some time studying the system to understand how to make a product that performed at 100%.

How long did the development take for your first fork?

Our first fork was the 33. It took two years to make our first forks, but the level wasn't as good as I wanted it to be, we weren't on the same level as the big players. But we learned a lot, we sold a few. Then we made the 35 and that was really our first fork with balls [laughs].

Was your CTS adjustable compression system the first big breakthrough for you?

The CTS system was born because we felt riders needed it. For the moto, you don't need to have a colour [editors note: Formula CTS valves are colour-coded]. an explanation that everyone understands because the final user never really touches their fork. They take it to a mechanic who does everything. They add their sticker, you know "X Suspension". The users aren't interested in what's happening inside, they just want it to say X Suspension. With mountain bikes, riders want to know what the mechanic did to the fork and to be able to do it themselves. The CTS was born because of this. There is the possibility to remove it easily, it's colour-coded so it's intuitive to understand, it's really simple for the users.

The CTS system is a completely different approach to changing the compression damping to any fork on the market, was it your idea? How did you end up with this system?

It was an intuition I had, I don't know how to explain it.

Is it something you see in moto?

No, as it's not only a technical innovation, it's part communication too. Technically it's really easy - remove, modify, re-mount. It's a communication, a collaboration with the final user. The final user has the chance to change the settings in their own garage - this is something nobody else has, you can normally only make these kind of changes in a specialist workshop.

You explained to me before that it has a similar effect to changing the shim stack, but without opening the fork.

It's quicker. Practically, if you take a look at Moto GP, moto in general for their special settings, and then the Formula CTS system you can see the difference. In Moto GP they modify both the piston and the shim - they will have settings for Valentino Rossi in the rain, settings for Brno, settings for Valencia. They change everything. With moto in general the piston always remains standard, you buy a Showa fork and you change the shimstack. In our case you don't modify the shims, you modify the piston. So there is only a single shim that remains fixed, so you don't change the thickness of the shimstack, but how the oil pushes against the shims. It's a different way to achieve the same thing, doing it this way there are so many ways you can modify the behaviour of the fork. You don't just change the number of holes, you can change how it supports the shim. There are so many options, in the same way, you can do so many different things with a shimstack - but the final user can do this at home, which most people can't with a shimstack.

Why did you choose not to use this system for your DH fork, the Nero?

For the Nero we skipped the CTS system because it wasn't needed. When you change the piston you change the heart of the system, it really changes the character of the fork. If you're just changing the shims through the adjusters you reach upper and lower limits of what you can do. With the single crown fork it's going on many different bikes used for many different things, different weights, ebikes, full suspension, and hardtails - for this you need a fork with a huge range to adapt to each bike, which is why we have the CTS system. Instead with DH the bikes are much more similar, their weight is similar, they're always full suspension, they're ridden in the same way. You can be more precise with your changes because the range of use for that bike is not that big, you don't need to be able to remove the system quickly. Without a lockout there is more space inside to do this - you're using the whole cylinder just for one thing and we can be more precise.

How did you decide how rigid you wanted the Nero to be? You don't seem to be chasing after the most rigid fork possible.

When we talk about why we chose 35mm stanchions for the Nero we need to talk about our experience with other forks on the market, because before you make a new product you need to study the market. We prefer to have a 35mm stanchion rather than a 40mm stanchion because it's more difficult with 40mm. A fork helps the damping when it flexes, it's easier to do the hydraulic side to deal with situations with vibration.

Having worked in both industries, what do you see as the differences between the moto and mountain bike markets?

There are a lot of differences. If we talk about the final users, as I said before, tuning for motos is done by mechanics. For mountain bikes there so much information, and disinformation, on the web. There is this desire to understand how it works. If we talk about the moto market, it's different, the approach sales is very different. When you sell, for example, as Suzuki it's completely Suzuki. With bikes, the frame is this, the brakes are that, the fork and shock are something else. That means as a business the impact of marketing is much bigger - you have to do marketing. With moto, you are only marketing to the manufacturers and if riders aren't asking for it, they won't spec it on a bike. Then there is the problem of support. If you want to sell products across the world you need to have a network for distribution, support and spares across the world. Instead if you make a trial fork for Honda it's sold as Honda and if the user wants spares or support they ask Honda. If you break the fork you send it to a Honda mechanic and he repairs it.

Is there a big technical difference in the suspension for the two?

The substantial difference between the two is the weight. As I said before in the bike industries we use different material, that in a way help to you to reduce the weight but in another way reduce also the life of the components. Another important difference is the function of the suspension due to the different percentage of the weights. For an offroad moto, 40% of the weight is the rider, 60% the vehicle. For a DH bike, 80% is the rider, 20% the vehicle. That means that bike the suspension has to be studied more in contact with the rider, and you must follow the riding style more.

It's interesting you mention having the right flexibility in the fork, because in mountain bike a fork is designed in isolation from the frame it will later be fitted to. Do you think that it's the direction things will head in, where companies produce a complete bike where they have control over the frame, the suspension, the wheels to have them all work together perfectly?

It would become too complicated if we told every brand we could make modifications for them. In my opinion, I do think it's right that we start to look in the same direction as the moto industry. But we can't do it on our own, you can't escape the general dynamic alone.

It surprises me that we don't see more of that approach in DH, where you're looking for fractions of a second, surely a bike designed as a complete system would be a big advantage?

Yes, in my opinion it is very important as it is possible to optimize the weight by putting it only where it is needed, moreover the elastic response if it is studied together with the frame gives the structure a certain continuity. For example, it is useless to have a rigid fork on an elastic frame or an elastic fork on a rigid frame, it doesn't work well. But. if you can engineer the continuity of the complete system, then I think yes, you can gain some seconds.

Between your CTS system, then your R spec forks with an adjustable negative air chamber, at what point do you think your products become too complicated for consumers?

I'm something I'm always thinking about. There are the decisions we've already made, but I wonder about the double air system, in the end I think it will come down to the bike manufacturers and what they want. We have done many products, but we don't have a constructor that is speccing a significant number of our components on their bikes. In the beginning, we didn't have the communication, now we have the communication, then we needed time to prove the products, now we have the reliability, and it's now their decision - but I think that is our future. We don't want to draw conclusions, we need to see what they want.

There are seven CTS right now

I'm not working on an eighth, not a tenth - there are plenty right now. To give you an example - XC. With the same damper, identical, but what do you want? Say you're descending and there are three stones then a corner. A DH or enduro rider will see that and think one thing, an XC rider will see something completely different. They will put their weight behind the saddle and take the hits with their body. A DH or enduro rider would use the first stone to jump the second and third stones and land ready for the corner. Obviously you can't have the same fork for those things. It's a completely different idea. That's why we have our special soft CTS. It's designed for XC where you don't want the same reactivity from your fork. The hard is much faster. Then there's the ebike to give you more support so you're not just relying on the air to take the additional weight of the bike. So if we explain our system well I don't think there are too many options.

I have had a colleague tell me that he thinks your forks are too complicated.

For a mechanic, with our fork in their workshop, they don't need many parts as they're all very similar. The damper is the same for all our forks - with the Selva all the different versions have the same cartridge. It's the same for 29 and 27.5, the whole range in fact. There are 7 CTS pistons and they work in all versions. We work to continually evolve the fork but the basics stay the same. Ask your colleague to try and find a part for a Fox fork from three years ago, there are so many different sizes and specs - ours is simple in that respect. Say you have the standard air spring you can easily change it for the coil spring or the double air, we may even release the triple air system from the Nero for the Selva. All with the same fork. Ok, there are a lot of options for you to play with, but that doesn't mean everyone needs to use them. But at the end of the day the fork is 50% of the suspension, the other 50% is the person using it and it needs to be adaptable as we are all different.

What is next for Formula suspension?

I have a unique project that I'm working on, but I can't talk about right now [Editor's note: that project turned out to be Formula's Neopos volume spacer system].

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