On Saturday, July 5, 2025, at approximately 9am in Morgan Hill, California, there will be no meetings taking place at Specialized’s global headquarters. Nor will there be any happening on the other side of the world, at Castelli’s offices in Fonzaso, Italy. Instead, all eyes will be locked on Lille, where the first stage of this year’s Tour de France will be reaching a fast and dramatic conclusion.

“We’ll all have to gather round one desk to watch it, otherwise the IT department will send emails round saying we’re killing the internet bandwidth,” laughs Sam Benedict, Global Category Leader at Specialized. 

“During the Tour, it would be really interesting to measure the lack of work that gets done from eight to nine thirty in the morning when the stage is ending, because putting in meetings then is literally pointless. If you send a calendar invite, people will be like, ‘What the hell are you doing?!’ There could be people around the world waiting to start the meeting, but we know what’s important here.”

A 185-kilometre loop to the west of Lille, with 997 metres of elevation gain, will decide the first yellow jersey wearer of this year’s Tour de France. On paper, there’s little to prevent a bunch sprint; only a few punchy climbs pepper the route, and plenty of teams will have serious interest in keeping things together for a frantic gallop to the line. The stakes on that Saturday are as high as they get in this sport: the leader’s jersey of the most spectacular bike race on the planet is up for grabs. Every sprinter in the world will want it, but employees squinting at live broadcasts of the race via phone or laptop screens from Specialized and Castelli will be gunning for one man in particular: Soudal-Quick-Step’s Tim Merlier. The pressure on the Belgian rider’s shoulders weighs heavily.

“To be honest, the victory in stage one will be a dream. It’s maybe the only opportunity like this I’ll have to take in my career,” says Merlier. “The finish village is not far from where I live. We go there in the winter to drink coffee or do shopping. My family and friends are already all talking about being there.”

July 5 is a date that has been on Merlier’s mind ever since race organisers ASO made the 2025 Tour route public. He’s under no illusions that winning will be easy, and that’s why the Belgian rider is doing everything he can to try to make it a reality. Sprinting, he says, is changing, and simply pushing the highest number of watts is no longer enough.

“In 2019 when I won sprints, my maximum speed was around 68 or 67 km/h and now I do 72km/h maximum speed. We go faster and faster. I saw this winter when I was with Specialized in the wind tunnel, Remco was testing a lot of time trial suits so I said to our team manager: maybe it’s an idea to have something like this for the Tour de France sprints too,” says Merlier.

“Castelli bought into the idea, which I’m happy about. They were thinking the same way. We’ve been testing in the wind tunnel in Milan and I'm curious what it will bring. Normally I wasn’t the guy looking for these margins, I tried to just worry about power and positioning, but imagine you lose a Tour sprint by four or five millimetres and you didn’t do everything you could. You’d be disappointed for the rest of your life. I’ve asked Castelli, Specialized and the team to do everything possible for the fastest set-up.”

Italian clothing manufacturer Castelli have long been known for their ability to think outside the box, coming up with innovative new solutions to meet the demands of professional bike riders. The most famous example is perhaps when the brand introduced the Gabba rain jersey in 2009 – a wet-weather garment which completely changed the way riders dress for rainy and cold conditions. Since then, Castelli have continued to try to find gains in every other area of the sport, with aerodynamics playing a crucial part in each new product produced to be used at the professional level.

“In 2007, we first introduced our aero jersey and then we started really pushing the limits on speed suits and time trialling. In those early days, though, it was easy to get the gains but it’s got harder and harder as it has gone on. Our standard stuff tests really well now,” says Steve Smith, Castelli’s brand manager.

“Now, we are really having to optimise individual solutions for individual riders and their specific needs. With Tim, we are targeting speeds of 70km/h which is very different from what we would do for general road racing. Our recent sessions in the wind tunnel have been isolating specific areas – shoulders, shorts, body, torso and moving seams. We’ve seen those things make a difference in isolation and the next round will see us bringing those together to find the cumulative benefits.”

Smith explains that Merlier will head to that important stage at the start of July with a number of choices when it comes to his skinsuit. There are options for varying weather conditions (with a chance that temperatures could soar above 30 degrees celsius) which aim to strike a balance between aerodynamics and breathability, born out of hours spent with Merlier in the wind tunnel in the lead up to the race. Castelli believes that the kit Merlier wears could be the difference between him winning and losing in Lille.

“If we consider everybody is at a pretty good level right now compared to 10 years ago, we can expect in the neighbourhood of a metre to half a metre gain at the line from Tim’s skinsuit,” explains Smith. “But it’s also about the overall dynamics of the sprint: sprinting is an acceleration up and the faster you go, the bigger the benefit is, because the aerodynamic drag is equal to the square of the speed, so smaller increases in speed have a bigger change. If a guy is going to come around you after being in your draft and you’re able to accelerate more and more, this can have a bigger effect than that distance on the line – it makes it harder for them to come around you.”

Specialized echo the fact that finding gains in sprinting is not just looking at what happens at the finish line, but analysing the process too. Chris Wehan has been part of the American company for over 15 years and now works as the Category Lead for Roval at Specialized, and he has noticed the shift in the demands of riders when it comes to equipment.

“We had a conversation with Tim when he came here over the winter and it’s so important to hear it from the rider’s perspective. I can watch racing on TV and have insights and thoughts, but to get the nuanced detail of it, of how they execute the sprint, for example, when they jump, when they create the gap, when they stay in the slipstream… I take pages and pages of notes back to my desk about that,” says Wehan.

“His acceleration phase for him is the most important as that’s the winning move. So my focus isn’t about making the most aerodynamic wheel at 70km/h but making the wheel that is the best at accelerating up to 70km/h. We’re now chasing how to make products for Tim and sprinters like him with a specialisation based on each of their individual styles.”

Part of what makes Merlier unique, according to the brands that work with him, is his late entry to road racing’s top table. The Soudal-Quick-Step rider learned his trade on the cyclocross field and only really broke through into the WorldTour peloton when he had his first professional victory in 2020 at the Bredene Koksijde Classic, aged 27. His first  – and only so far – Tour de France stage win came one year later, so even though he is 32, Merlier is still learning what it’s like to be treated like one of the best riders in the world.

“When people ask me for pictures, it’s still a shock to me and I’m not really used to it. Sometimes I find that more stressful than the race itself,” says Merlier. “Last winter was only my second time really in a wind tunnel, so I was so excited to see everything, it’s all really new to me at the moment.”

Smith says that the buzz Merlier gets when testing new technologies alongside Castelli is evident: “He absolutely loves cycling, loves the sport. It’s like he’s a kid living his dream. While he is good at trusting the experts, he also wants to express how he feels and is willing to do his part of the work. Some top-level riders don’t want to spend time in the wind tunnel, whereas for Tim it is part of the job.”

Wehan shares a similar sentiment from the perspective of Specialized: “I think for me, he’s just always a fun and excitable person to talk to. He’s a big name in cycling but he doesn’t really come off that way.”

Having face-to-face contact with athletes and getting to know them on a personal level is imperative to the development of new kit and products for the teams that both Castelli and Specialized choose to sponsor. As Smith points out, Castelli’s famous Gabba was born out of plenty of contact time with professional cyclists, understanding what they needed when it came to foul-weather clothing. Similarly, Specialized have even created their own development programme, coined ‘Project Black’, in which the company uses feedback from professional athletes to create and test advanced, pre-production products. This feedback is then used to refine and improve what may eventually become available to the public.

“Road racing is pretty traditional in a lot of ways and they don’t always want to change things. When you start to build a relationship and have that trust, listening to their questions and being physically there – whether it is a bike fit, a shoe, a helmet, wheels or tyres – the relationship is critical,” says Wehan.

“I remember one of the biggest things 15 years ago was that we wanted to raise the rider’s stem. They were like, ‘Are you fucking crazy? We don’t raise the stem.’ But we really lowered the CDA [Coefficient of Drag Area] of riders. They’re amazing at what they do but we have expertise and understanding to make them better at what they do. The conversation and trust is critical and it allows all of us to make better products.”

When it comes to new Roval wheels and tyres that Merlier and his Soudal-Quick-Step team-mates are expected to be using at this year’s Tour, Specialized admit that they have been testing these in plain sight since last July. Social media and keen-eyed journalists can often spot unreleased products before the brand wants them to be public, but it is a risk worth taking for the benefits of testing in real-world environments.

“We want to test with the best athletes in those situations. A rider never goes as hard in training as they can go in races. Yes, people have seen the new wheel and we’re always working on stuff like that in the pipeline. What we are working on goes back to marginal gains and specifying this per rider. It’s no longer about how a wheel performs at 50km/h on this graph, because that’s not how sprints are won,” explains Wehan. “Sprints are very dynamic, specific situations and so we are looking at how we move down the line towards crazy, optimised, millimetres of marginal gains because that’s the difference now. It’s about how we engineer in the moments that matter most. We will come up with something pretty exciting soon, and it’s going to change the way that wheels have been looked at on the road since the start. It’s going to be different, and it’s going to be faster.”

Feedback and testing has also been important to Castelli throughout their time working with the WorldTour peloton. Smith explains that they have a ‘race division’ in the Castelli office, with a dedicated team of staff who are in contact with Soudal-Quick-Step every day, gathering feedback and demands from the riders themselves. While a skinsuit can provide the best test results in the wind tunnel, for example, it still needs to be comfortable enough for riders to spend five or six hours wearing it in the saddle.

“Our team builds up a personal relationship with riders and figures out exactly what is going on – it encourages them to be more collaborative and more involved. We don’t want riders to just tell us what we want to hear to keep the sponsors happy, we try to encourage them to talk about the good, the bad and the ugly and they need to see we are responsive to this,” he says.

From his skinsuit, to his helmet, to his bike, to his wheels, to his shoes, to his tyres, everything is primed to try to help Tim Merlier win the first yellow jersey of this year’s Tour. He knows the investment, time and commitment that has gone into making him the fastest man in the world from his team and sponsors, but he now has to do the hardest part: executing victory on July 5, 2025. He’s thought about how the stage will go, and is relying on his close friend and leadout man, Bert Van Lerberghe, to deliver him to the line.

“Because I’ve already done the Tour once, I knew how to do it. But the Tour is the Tour and we need to go faster this time. We need to be prepared for every scenario and this Tour will also be different because the team will protect Remco [Evenepoel] for the general classification until the last three kilometres when the time gap will be taken,” says Merlier. “Normally, we can join the team there and then it’s up to us, me and Bert, to be in the perfect position to launch the sprint.”

Van Lerberghe and Merlier are childhood friends, and it is this close relationship which they believe make their leadout combination such a successful one (Merlier has 57 victories in his career so far, many of which have been alongside his compatriot.)

“We have been friends since we were 12 years old and our friendship makes us work well together. Even when we haven’t been part of the same team, we actually found ourselves in the same spot in the bunch. We have the same way of thinking and vision to get into position. I have a lot of confidence in Bert. He’s a strong horse and a big guy, which makes some space for me. It’s going to be important we hit the wind at the right moment and he knows where to bring me in that last kilometre.”

And what if it all works out? If Merlier takes his second ever Tour stage win on his Specialized bike, Roval wheels and in his Castelli skinsuit in Lille? Will all of the testing, hard work and sacrifice have been worth it?

“For us, it just gives us an amazing story to tell. You can’t pull off a Tim Merlier fastest speedsuit in the world if you don’t have the base of knowledge that goes into everything we’ve done to get him where he is today,” says Smith. “It wouldn't be possible if we hadn’t had a decade and a half of aero research and accumulated knowledge behind it, and then what Tim does on stage one of the Tour is a representation of what we know and what we’ll continue to do in the future.”

Specialized’s Sam Benedict is in agreement with Smith that there is no better indication of where a brand is in terms of modernisation and being ahead of the curve than winning at the biggest bike race in the world. He argues that this goes beyond just individual success for Tim Merlier, however, and it trickles down to the everyday cyclist who will be watching the opening stage of the Tour de France at the start of July. That’s the power of the race.

“It all comes back to providing a true performance benefit for our riders. When you provide for the literal best in the world, there’s no better stamp of approval that says to every rider out there that if it’s good enough for Tim then it is good enough for you,” he says. 

“Not everybody is a professional cyclist, but if the best trust us, we can translate that to normal people. At the end of the day, it’s fun. We love to compete, we love to win and the return is always that it makes a better product which gets people excited about riding and that feeds the entire ecosystem. The direct dollar return of Tim winning a stage of the Tour, we can try to take a guess at that, but it’s not the point. The point is furthering cycling along and continuing to get people to enjoy this really fantastic sport.”