How Trek-Segafredo does bike fitting

A conversation with Paraic McGlynn about bike fitting and the new Speed Concept

Paraic McGlynn has been doing bike fitting for Trek-Segafredo for the last eight years, though he prefers the term “cycling analysis.” There’s a subtle distinction. “Bike fitting” has become a catch-all for anyone who maybe adjusts a saddle or handlebar height, regardless of their methods or experience. The cycling analysis he does is a rigorous process that uses scientific technology and focuses on biomechanics.

“We have someone completing a PhD in biomechanics on staff and we have a doctorate in physical therapy who has vetted everything that we do,” McGlynn says. “We’re grounded in all the existing science. We are grounded in best practices from a physical assessment standpoint. Everything we do isn’t based on our opinion about things; it’s based on verifiable facts about how we approach optimizing athletes.”

McGlynn is also the founder and owner of Cyclologic in Scottsdale, Ariz., where he frequently works with high end endurance athletes. His expertise in aerodynamics and biomechanics played a role in the development of the new Speed Concept, released Thursday. His verdict on the bike?

Everything we do isn't based on our opinion about things; it's based on verifiable facts about how we approach optimizing athletes.

“When [the athletes] all come back and they’re giddy and they’re like, ‘Holy crap, this is way faster,’ that’s the best scenario,” McGlynn laughs. “When the athletes are coming back with big smiles on their faces and everybody is going, ‘This feels really fast,’ that’s not always the case when you make something faster.”

McGlynn sat with the Trek Race Shop to explain Trek-Segafredo’s bike fitting process, and dive even more in-depth on the new bike. The following conversation has been edited for clarity and length.


Paraic McGlynn going through the data.

What takes place before you get hands on with an athlete?

Paraic McGlynn: When we start to work with an athlete, the first thing we do is we review the medical history. When I started working with Trek-Segafredo eight years ago, we brought the physical therapist that Cyclologic had been working with for 20 years. So the fundamental basis for doing cycling analysis is that we understand the body first, and the way you understand the body is by assessing the flexibility of all the key muscle groups, not just the ones that create force, but also the ones that stabilize. 

So we do a combination of flexibility and strength assessments, and then we look for major structural asymmetries. So we look at the bony structure of the body, too. And once we have an idea how that person’s body functions, what their limitations are, what their performance opportunities are, we’ll then begin using a multi-planar, multi-disciplinary approach. In other words, we shoot high speed video from multiple directions. And we’ll use pressure mapping to determine how the body is interacting with the bike.

Once we combine the interview with the physical assessment, with the motion analysis, and with the pressure mapping, which is about an hour into the process, then and only then will we consider making any changes. So it’s a very measured, rigorous process. 

With WorldTour athletes you have to be very measured and very specific about what you do and how much you change.

What’s your process once you start physical testing?

So we have the history in physical assessments, we have the foot evaluations, we have the video analysis, the motion analysis and the pressure mapping in the saddle and/or in the shoes. And then based on that evidence, we use a process called critical reasoning, and in that critical reasoning, we identify a hierarchy of what I want to work on, because sometimes we don’t have a lot of time to work with the athletes because they have a lot of other demands on their time. 

Then, if they’re an athlete that we’re focusing on for time trials, we’ll bring them to the velodrome. We’ll do aero testing on the velodrome where we’re looking for a position that’s sustainable and has good breathing mechanics with a special proprietary process of tracking how they breathe as we change position. And then we’ll do a separate process where we take them out on the road and make sure the position is feasible out in the real world. And then each day as they go riding at camp, and they come back, I’ll be waiting to get feedback on how the position felt, how the change in saddle felt, how the new aero position felt. 

Because these athletes are so finely tuned, we will sometimes make small changes based on that. When you make a change on an athlete at that level, because they have millions and millions of repetitions in a position, it’s not like working on a recreational athlete where you can make relatively large changes because there isn’t as much adaptation at play. With WorldTour athletes you have to be very measured and very specific about what you do and how much you change. Sometimes that will be a phased process. You will make small changes over the period of camp, or over the period of a season.

Ellen van Dijk on her way to winning a World Championship on the new Speed Concept.

When working with Trek-Segafredo riders, where does the majority of this testing take place? At team camp?

McGlynn: It’s a combination. So the majority of the work is at team camp, but let’s take Ellen van Dijk for example. So Ellen has had some injuries related to crashes. She’s had some saddle challenges. So it’s very much a team approach. Josu [Larrazabal], her coach and trainer, will keep us in touch with Ellen with what’s going on. Nate [Koch, physical therapist from Endurance Rehab,] will prescribe strength and flexibility drills to help maintain a good saddle interaction because her core is strong and because we have injuries issues. And then I’ll have positional inputs as riders recover from crashes. 

There are two types of positions. There’s an optimal position, in which the athlete has no limitations and we are pushing the position to its limits, so to speak. Or athletes have what we call an “accommodated position,” and an accommodated position has to morph with the athlete as they lose fitness, or regain strength. 

So in Ellen’s case, we started with a conservative position, we started with a particular saddle, and then as she got stronger and got fitter, that position became more aggressive and more race appropriate. And all of that culminated with her winning European Championships this year, and World Championships in the time trial. That was a multi year process for Josu, Nathan and myself working together on getting Ellen to the point where she could perform at a world class level again. 

So in a given year, I’ll see the athlete between two and four times, and depending on what they have going on, there may be offline interactions between us and the coaching staff and the physical therapist.

Trek gets ahead of the game and does fit camp at the end of the season so that by the time they arrive at team camp, it's very seldom that we haven't had our hands on an athlete. 

You live in Arizona, and you work with athletes all over the world. Does that make your job difficult, especially when you’re making such small changes?

McGlynn: Some of these athletes we’ve worked with for four, five and six years, so you have more data points on those athletes, so they’re easier to work with. But the athletes that are new to the team, sometimes we need to see them several times because we’re dealing with very different equipment, different saddles, different shoes. And Trek-Segafredo has an amazing team of product engineers that will sometimes do special tweaks and accommodations to equipment. So it wouldn’t be unusual for an engineer to be involved with some specific accommodation for an athlete because of an injury or some other condition.

But there are times when it’s difficult because I can’t put my hands on an athlete all the time. And even though sometimes I will go to races, sometimes the athlete that’s having issues isn’t even at the race. So there are times where it can be frustrating to work at such long distances. The team is working on having more resources for athletes during the season because being in the United States can be a bit of a hurdle. But we also have other fitters that we work with in-season.

McGlynn working with Trek triathlete Holly Lawrence.

Do you ever make BIG changes with riders just coming into the team?

McGlynn: So there’s a massive range. Believe it or not, some of the athletes we work with have never been fitted before. And some of the teams don’t provide fit, so the riders and the mechanics dial in their fits by subjective feedback. So Trek-Segafredo, as a team, is highly progressive. 

They generally fly me into the Tour of Lombardy and we’ll see all the new riders. At the end of the Tour of Lombardy we’ll do shoes and cleats. Santini will be there, again, as another part of this village of people that help make a fit work. They’ll try new chamoises, they’ll try new clothing, they’ll get new skin suits, we’ll fit them for their aero helmets, we’ll get the cleats set up, we’ll talk them through adapting to a new pedal system. It’s new saddles, it’s new bike geometry, it’s one piece bars vs. two piece bars. 

Trek gets ahead of the game and does fit camp at the end of the season so that by the time they arrive at team camp, it’s very seldom that we haven’t had our hands on an athlete. 

The most underestimated thing in working with pro athletes is you have to be a great communicator, and you have to read the athletes' non-verbal language. 

How much can a rider’s fit vary from one bike fitter to another, even supposing that the different fitters are highly trained?

McGlynn: The challenge sometimes with education of fitters is that people tend to bring bias to any situation they’re in. And a lot of fitters have things that are their specialties, like pedal dynamics, or footbeds, or whatever they’re most passionate about. I think the most important quality for a fitter is to be really good at everything. You have to be really good at physical assessments, you have to be really good at observing the body. And maybe the most underestimated thing in working with pro athletes is you have to be a great communicator, and you have to read the athletes’ non-verbal language. 

When you’re working with professional athletes, it’s better to do less than more. We’ve taken experienced fitters and sometimes we see if they can work with professional athletes. And a lot of times they can’t because they try to accomplish too much. They try to make too many changes and it doesn’t work. Or they’re not able to read the body language of the athletes and see that they’re not comfortable with certain changes. 

And then the other thing I’d say is that some fitters rely too much on technology. We use a lot of technology, but also, I did my first bike fit in 1991, and I’ve been working with professional athletes for over 30 years. There is a component of being a bike fitter that’s just about repetition, and pushing your boundaries to learn all the time. Cyclologic is in a medical building. We learn more about new rehab techniques, we learn more about new physical assessment techniques all the time. 

When you’re working with the human body, the only constant is change. So the fitters that do a course and just repeat that without growing, they’re going to have different answers compared to that group of fitters that have education, technology, good protocol and are mainly exposed to medical professionals so that they can continue to grow their palpation skills and their assessment skills. That group of fitters are going to produce very similar outcomes.

Making a cleat adjustment.

What are some of the biggest misconceptions about bike fitting?

McGlynn: When we work with athletes, what looks aerodynamic is often a myth. We joke that “low is slow” every time we go to the race course or to the track. 

I think there’s a perception of aerodynamics that you have to be in this crazy elaborate, low, super narrow front area position. And for some athletes that’s true, but for the majority of people you need to be on a bike that gives you a really big fit window so your fitter can get you into a position that balances aerodynamics, power and comfort. 

Modern aerodynamics is no longer about slamming people down and putting them in super aggressive positions. We actually have a tool that monitors breath rate, core body temperature and body angle, so we’re actually looking at the ventilation and a lot of other factors. 

You have to have really fast equipment. You have to have really great engineers and a really great team behind the bike. But then you have to have somebody in the cycling science role making sure that that athlete can push the pedals really hard, can breathe and is as aerodynamic as possible without messing up the other two things.

Modern aerodynamics is no longer about slamming people down and putting them in super aggressive positions.

What are your thoughts on the new Speed Concept? And what input did you have on its design?

McGlynn: We have a professional triathlete on staff who helps us with a lot of our tri-related product, and he was one of the test pilots. So we’ve been involved with the Speed Concept for over a year now, whether it’s having input into aerobars and fit and extensions, or it’s getting athletes onto bikes. We’ve put probably 25 Trek-sponsored athletes onto Speed Concepts, and some of them we’ve done aero testing on. 

Our pro athlete, Evan Pardi, was one of the first people to ride it. A lot of Ironman courses are not very smooth roads, and there’s a part of the Ironman course here where the shoulder is kind of rough. So on the first ride that Evan did with IsoSpeed, I mean, we couldn’t shut him up. He came off a different brand’s bike that had no suspension, and he just went on and on and on about how smooth the Speed Concept was, and how he felt that he could stay more relaxed in aero because the IsoSpeed made such a difference to vertical compliance. He said he felt like unless he had to take out food or something, he had absolutely no reason to come out of the aero position. And he noticed during workouts afterwards that he was less fatigued, his back was less stiff. He just couldn’t believe the difference that IsoSpeed made.

IsoSpeed means riders don't have to sacrifice weight or aerodynamics for comfort.

Then for me, as a performance specialist, I got really excited when we took the bike to Valencia, Spain, and we started doing some aero testing on it. It was crazy fast compared to everybody’s last trip to aero testing at the track. Everybody had significant wattage savings. Every single first ride on the new Speed Concept was significantly faster. It was a double digit aero wattage savings for every single athlete. For me, because I’m a retailer as well, to see that bike crush it performance-wise for every single person was just amazing. 

Obviously that’s the goal. But when the athletes are coming back with big smiles on their faces and everybody is going, ‘This feels really fast,’ that’s not always the case. People don’t always come back beaming, especially professionals because they expect it to be faster. They expect it to be better. But when they all come back and they’re giddy and they’re like, ‘Holy crap this is way faster,’ that’s the best scenario. 

When you’re there with the Trek engineering team, and you’re there with the team liaisons, there’s always a sense of trepidation when you go to test a new product. But when everybody is just gushing about it, you know that it’s special.

Everybody had significant wattage savings. Every single first ride on the new Speed Concept was significantly faster.

What features stand out to you?

McGlynn: I have to give props to the guy behind it. John Davis is an aerodynamicist rocket scientist. He is the archetypal guy who could be designing weapons for the military but instead he’s designing bicycles for Trek. 

The reason this bike is fast is because of science. It’s because of a supercomputer, and then probably billions of combinations and permutations that they process to come up with the shape for this bike. So when you have that much science and engineering baked into a product, and when you have a stacked engineering team the way Trek has, that product is going to shine. 

And when you look at that bike, and you look at the way the cockpit is engineered on the road side, when you look at the tubing shapes, when you look at the progress that they’ve made with the wheels, and you start looking at that whole thing as a system, and you think about how all these things function together and all these teams work together within Trek, it is pretty stunning. And then you see it perform. 

Holly Lawrence showing off the new Speed Concept.

And then on the tri side, it’s the integration. So when you look at a current Speed Concept in race regalia, there are a lot of things going on outside the bike. With the new Speed Concept, there’s a ton of innovative storage, there’s the “BTA,” between-the-arms bottle.

The most important thing for us working with triathletes is that it has the same giant fit window compared to anything else that’s out there. The range of positions I can put a rider in on a Speed Concept, there’s no other brand in the industry that’s even close. So you’re getting superior integration, you’re getting superior comfort with the IsoSpeed technology, you’re getting a crazy configurable cockpit, and you’re getting all that engineering and all that know-how baked into that frame because of that deep, deep knowledge base.