Trek suspension R&D – finding the perfect balance

"It doesn't happen by chance." Jose Gonzalez

People, allegedly very informed ones, say there is no such thing as a bad mountain bike these days. One of the most striking things of testing bikes is how very quickly adaption takes hold, it plays a big part in this idea that most company’s do not make mistakes. How very wrong.

There is a profusion of suspension systems all purporting to have the optimum design. Many of these are pretty good, others lead to hideous fatigue due to too much progression or tiredness a result of continual rider counterbalancing or guessing what the suspension is doing. Geometry and materials play a part in this too but the key is having parity, to create a system where the suspension and damping works together letting the rider adapt to the terrain, not the bike.

The problem is the mountainbike industry is full of bright ideas and all too often the whole business of getting the kinematics and damper in unison is left to chance. Many brands have no base settings leaving the rider either to work it out for themselves or buy a £300 SRAM widget to do it for them. And then think it’s ok to charge to punter upwards of a 450 KTM for the privilege of….well mostly image.

One of the most striking features of Trek bikes, be it a Session, a Remedy or Slash is that they have an identifiable feel to the system, you could say the same for Specialized, Orange and a few others. The characteristic is nearly always second nature when riding and rarely doing daft things. As a test rider this means that I never had to make that painful call that you just know will lead to only one outcome “well that’s your opinion.”

Jones at Highland 2008 launch of the Session

Now the Trek Session was not perfect at the start. It had replaced the Session 10 (thank god), it was way lighter, skinnier and altogether prettier. It was faster too, but the damping was someway behind what the Session offers today. But it became VERY fast very quickly. When Aaron Gwin moved across from Yeti in 2011 he immediately raised his game and so it became that the Session is now one of the most winningest bikes in the history of downhill.

Jose Gonzalez was a key person in making that system work, along with the latest RE:aktiv units working with Penske. In today’s crammed market there has to be a performance advantage, and suspension all too often plays second fiddle to cosmetics. At their base in Santa Clarita, Los Angeles, Jose Gonzalez and his team define how and why Trek suspension works as it does, working closely with Trek chassis engineers and designers to produce that characteristic Trek feel.

As Gozalez says “It didn’t happen by chance….”

Dirt. As we discussed Jose…getting a bike to work correctly. It doesn’t happen by chance right?! 

Gonzalez: Absolutely not! It takes a lot of thought process, smart engineering and lots of field testing. Test riding…and then more test riding…is a huge part of ending up with a dialled bike.

Good geometry alone does not make a bike?

Rear suspension kinematics and shock tuning are a major part of dynamic geometry which is essentially the geometry the rider feels when the bike’s in motion. Static geometry is just that – a geometry that gives you some idea of the ride characteristics but not the whole picture. We can have two identical static geometries that ride completely different based on rear suspension kinematics.

People say there are no longer bad mountain bikes. Agree or disagree?

When it comes to most quality brands, I believe most are good and it’s mostly about specific ride philosophies and performance balances – what do you want that bike to feel like in motion. But there are still some pretty poorly designed kinematics out there.

Poor suspension design is still prevalent with many mountain bike brands. Agree or disagree?

I agree that there are still some poor kinematics out there. Some of the designs are so handicapped that even a good shock can’t fix it.

What is your philosophy on damping/suspension?

Mid stroke support and control is critical. Mid stroke characteristics defines the ride dynamics and dynamic geometry the most. It influences stability, control, cornering and it’s critical to good deep stroke control while maintaining good push through for consistent use of travel.

Additionally, balancing the mechanical system (kinematics) with the shock and vice versa is very important for a balanced performance. I’ve never understood how some designers can claim that you don’t need compression damping if you have a certain mechanical system. Dampers are transient devices where a mechanical system is not, meaning that a mechanical system operates the same regardless of type of input/bump whereas a damper is very sensitive to the type of bump.

Dynamic geometry. That’s an easy topic to discuss Jose?!

Dynamic geometry is definitely not an easy topic but such a critical one for great handling and great bike characteristics. Dynamic geometry is the culmination of geo numbers, kinematics, shock and fork characteristics, rider weight bias, tuned frame stiffness…there’s quite a bit to it for sure.

What effect will poor dynamic geo have on performance, handling and rider fatigue?

Besides the bike handling like crap and not being fun to ride, it tasks the rider a lot and introduces both mental and physical fatigue very quickly. As a test rider, I’ve ridden bikes that I was so glad to get off of it after I concluded my test requirements. It was not only not fun to ride, but it was mentally draining and physically tense because you felt on that edge all the time and couldn’t ride with confidence and relaxed.

How important is it that riders adhere to your base settings?

You know, base settings are just that – it is a good starting point to get you in the ballpark. Our base settings are derived from a lot of field testing with different level riders – all the way from Elite to the novice rider. Ultimately, we want to present a starting point that will allow the rider to get close enough to the designed performance in the bikes that it will be a positive experience right out of the gate.

But it is just a base setting and recommended starting point. There are rider preferences and styles that may require additional tweaking to get it optimal for them. However, it’s much easier to get there if you have a good starting point.

How close is your relationship with the frame designer? How does the business of kinematics and damper tuning work out in reality?

That relationship is very, very tight. Our frame development crew and our suspension development crew are basically one team. We discuss each platform up front and determine what the requirements are, what kinematics are desired for that chassis, what shock technology we need, what leverage rate and ratio will complement a specific shock technology, overall requirements, etc. There’s quite a bit of back and forth before we cut any metal. And then, we also roll in the suspension partner into that mix at some point. It’s a pretty involved process… but that’s what it takes to build great riding bikes.

How do you validate what you are doing with suspension?

We have numerous tools and processes that we use which includes both scientific and subjective analysis. We have a pretty structured field test program that documents and controls our ride testing. We firmly believe that ride testing and rider feedback is the most important data point. But we also use and quantify with data acquisition, high speed cameras, suspension dyno, timing of different sorts, heart rate monitor, GPS…

What/are there any different challenges balancing a bike that is going faster through rough ground with reference to 29 vs 27.5?

The main thing we’ve found is that you’re able to carry more speed on the 29” wheel and you’re a bit more stable due to the greater self-correcting nature of the bigger wheels, so you can drive in more “monster truck” like. Also, the bump frequency changes a bit when compared to going through the same section on 27.5” wheels. Fast cornering also becomes calmer on the 29” wheel which influences things as well.

How much do you work on ‘the system’ – flex/stiffness within chassis, wheels, components and suspension performance?

Quite a bit actually. Like you state, it’s a system and it is the system that adds up to optimal performance and ride characteristics. Terrain tracking and control goes well beyond suspension performance. There’s also frequencies and inputs that are difficult for the suspension to react to so it’s these other elements that contribute to ride characteristics in those moments.

How much work do you do with factory riders?

We use the factory riders at specific times during a development but you need to remember that those riders are focused on results and doing their job between the tape. Their success depends on having stuff that is proven, dialled for their specific style and that they are completely familiar with in the way it’s going to respond and act. It’s what allows them to push to the fine edge at the highest levels. What I’ve found in the many years of working with Elite level riders is that they don’t always end up with the optimal set-up for pure suspension performance for example. But it is the set-up that allows them to perform at their very best with full confidence. In many cases, they don’t even enjoy riding those set-ups outside the tape!

The Session 29, one bike in a long list of great's worked on by Trek Suspension R&D

How much R&D work is done in public?

More than people realize…

We have a large contingent of R&D test riders that are constantly trying things for us, both in private settings and under the public eyes. Many of these test riders are domestic Pro riders that test product through the crucible of competition. Some stuff is easier to hide than other.

Obviously, when Cole Picchiottino was racing a Session 29 prototype over the last 16-18 months, it’s pretty hard to hide the fact that it’s a prototype and it’s different. But the R&D benefits more than outweigh the fact that other riders knew we were testing a 29 DH bike. However, in other cases such as when Christian Gonzalez raced all of last year on a new Session geometry that we were developing, no one was really able to tell. That geometry is now something were going to leverage going forward.

Will we see the Atherton’s on a 29” DH bike this year?

I think I heard your Mum calling you…

Will we see RE:aktiv on a downhill bike?

Better go, I think she’s yellin’ now!

Will we see Rachel or Gee Atherton on a 29" wheel DH bike this year?

Does your research show 29 to be faster than 27.5” on a downhill bike in every situation?

When racing the clock, the 29” wheel is basically more efficient, stable and faster. And with today’s geos and component development, such as Boost wheels, great tires and equal suspension, it really all comes down to what bike characteristics the rider prefers. That’s the part which is specific to the rider and there’s no right or wrong. A given rider will always go faster on what they feel the most comfortable on and suits their style best.

Do you believe riders will have the choice of 27.5” and 29” downhill bikes in the future? And if one has an advantage over the other is that fair?

Yes, I do believe that we will see riders having that choice in the very near future. We’ve done a lot of 29” DH development over the past 6-7 years and we come a long way with that bike. It’s now not just a good 29er DH bike but more of a great DH race bike, period.

The 29” wheels will always be a more efficient, stable and faster but there’s a lot more to it than just that – course approach, rider style & preference, etc. also comes into play. Plus, once outside the tape, seconds don’t matter and it’s all about fun. Enjoying the experience means different things to different riders and they can both be great bikes. That’s why I feel you’ll see the co-existence of 29” and 27.5” for quite a while.


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