The Art of Compromise: Building a Climbing Aero Bike for the Toughest 70.3 Course

How Jamie Riddle's 6.8kg Felt Nexar FRD challenges everything you thought you knew about race-day bike selection — and what every triathlete can learn from his bold equipment strategy.

When the world's top triathletes gather in Nice for the 70.3-distance World Championship, most will be on sleek, ultra-aerodynamic time-trial bikes designed to cut through the wind. But Jamie Riddle has opted for a different strategy. This British pro has boldly swapped the traditional TT bike for a lightweight 6.8kg aero road setup tailored for climbing, descending, and tackling the winds of one of the toughest 70.3 courses around. It's a decision that may raise eyebrows, but when you look closely at the specifics, it all starts to make sense.

With a staggering 1,244 meters (4,101 feet) of elevation gain from Plage des Ponchettes up through the Alpes-Maritimes, the Nice bike course is anything but average. It's a true test of mountain endurance wrapped in a triathlon experience. Riddle's bike reflects that reality perfectly.

In this article, we'll dissect every feature of Riddle's race-day setup — his Felt Nexar FRD — and explain why he made each choice, what it means for his performance, and how age-group athletes can learn from a pro who breaks the mold when faced with tough challenges.

The Course Demands Everything

Understanding the Nice Challenge

To truly appreciate Riddle's unique bike choice, it's essential to understand the demands of the Nice course. The route from Plage des Ponchettes isn't your typical flat or rolling course. Instead, it brings 1,244 meters of climbing — almost 4,100 feet of vertical gain — through the stunning Alpes-Maritimes region. This course features long Alpine climbs followed by technical descents, requiring firm handling, effective braking, and a bike that remains composed when gravity goes into overdrive.

For perspective, most 70.3 races have around 300–600 meters of elevation gain. Nice nearly triples that number — it's a course that truly demands unique strategies and equipment.

The TT Bike Problem

Here's the prevailing belief: pros tackle 70.3 races on dedicated time-trial bikes. These bikes are low, aggressive, and optimized to minimize wind resistance. This setup performs fantastically on flat or rolling courses where aerodynamics is the main concern. However, on a challenging course like Nice, that logic changes entirely.

Traditional TT bikes present several issues in mountainous terrain:

• Their aggressive geometry becomes uncomfortable and less efficient on extended climbs.
• The extra weight (usually 7.5–8.0kg) becomes a liability over 4,100 feet of ascent.
• Handling on fast, technical descents requires more skill than a road-designed bike.
• Long, steep descents pose braking challenges, as stopping power can be limited.

Riddle's choice isn't made on a whim — it's a sound decision backed by physics.

"A bold strategy, but together with some amazing partners, we have managed to piece together what I am confident will be the lightest bike at 70.3 world champs in Nice."

Bold? Yes. Effective? We think so, especially with extensive analysis and competitive experience backing it.

The Felt Nexar FRD — Felt's Lightest Aero Weapon

Why This Bike, Why Now?

Launched in March 2025, the Felt Nexar FRD is redefining bike racing paradigms as an aero road bike. It's neither a pure climber nor a full TT machine — it strikes a balance between aerodynamic strength and climbing skill, and it has quickly become Riddle's trusted racing partner. The Nexar FRD is Felt's lightest aero bike, which becomes crucial on a course where even saving 100 grams can save precious seconds uphill.

Riddle's complete setup — including frame, wheels, and components — weighs around 6.8–6.9kg. When compared to the typical TT bike at 7.5–8.0kg, that's a 700–1,200 gram weight advantage that adds up on every hill. This bike combines aerodynamic tubing with geometry that allows for confident descending — something a pure TT bike cannot deliver. Riddle has proven the effectiveness of the Nexar FRD in numerous successful races since its release. This isn't an untested theory; it's a fully-fledged, race-ready setup.

Component by Component: Built for Climbing and Aero

Every aspect of Riddle's bike has dual roles: climbing efficiency and reduced aerodynamic drag. No weight is wasted, and every choice is purposeful. Let's break it down.

Drivetrain: Geared for the Mountains

The drivetrain illustrates Riddle's thorough understanding of the Nice course.

Key drivetrain details:

• Chainring: cSixx 56T (aero design, single ring setup)
• Cassette: SRAM 10-33 (wide range; the 33T gear helps on steep pitches)
• Crankset: Shimano Ultegra 170mm with integrated power meter
• Chain: Shimano Dura-Ace (lightweight, high performance)
• Rear derailleur: Shimano Dura-Ace Di2 RD R9250 (electronic shifting)

The chosen 10-33 cassette gives Riddle the all-important "bailout" gear for those steep ascents. This gear allows him to maintain a steady cadence and protect his legs when tackling double-digit gradients. Paired with Shimano's Di2 electronic shifting — which offers seamless gear changes exactly when needed — this setup makes climbing a whole lot smoother. On steep and technical terrain, where you're working hard, the instant click of Di2 takes away one more distraction.

Cockpit: Aero Meets Road Bike Geometry

The front end showcases Riddle's clever strategy. By choosing the right components, he maximizes aerodynamic efficiency without sacrificing the benefits of road bike geometry.

Cockpit components:

• Base bar: Vision aero bar
• Spacer: 3D-printed custom spacer (lightweight, tailored fit)
• Cockpit: Tetsuo Masamune
• Aero mount: BTA mount with TriRig BTA Pro kit (for data display)

Adding aero bars to a road bike captures much of the aerodynamic benefits you'd get from a full TT setup — but without the handling limitations and additional weight. That 3D-printed spacer adds a level of precision that transforms professional race prep from guesswork into strategy.

Braking System: Built for the Descent

Descending from the Alpes-Maritimes is a thrilling challenge. These long, steep descents require reliable braking systems that inspire confidence.

Brake setup:

• Calipers: Shimano Dura-Ace BR R9270 two-piston hydraulic disc
• Front rotor: Shimano RT MT900, 160mm
• Rear rotor: Shimano RT MT900, 140mm
• Shift levers: Shimano Dura-Ace Di2 ST R9270

The rotor sizes are intentionally chosen. A 160mm front rotor offers maximum stopping power for those quick descents, while 140mm at the rear provides enough control without adding unnecessary heft. Hydraulic disc brakes maintain performance regardless of weather conditions — crucial on those long Alpine descents where stopping power can be compromised. This is one of the areas where an aero road bike shines compared to many TT setups.

Wheels and Tires: The Climbing-Aero Balance

Choosing the right wheels for a climbing course is intricate. Too much depth, and you deal with greater weight on climbs; too little, and you lose aerodynamic efficiency in flatter sections. Riddle's choice? ENVE Pro wheels with a 100mm front and Pro Disc rear.

Why this setup excels:

• A 100mm front wheel provides substantial aerodynamic advantages without the excess rotational weight of deeper wheels.
• The Pro Disc rear adds speed efficiency when the road flattens out.
• ENVE is known for its lightweight and rigid construction, meaning no energy loss on climbs.

Riddle was still weighing tire options leading up to the race, considering the Continental Grand Prix 5000 TT TR (great for rolling resistance) against the Pirelli P Zero Race (excellent grip and climbing feel). Keeping his options open reflects Riddle's adaptable approach — ready to make a final call based on race-day conditions.

Saddle and Hydration: Every Gram Accounted For

Riddle's attention to detail extends to his saddle and hydration choices. He rides the Wove time trial and triathlon saddle, optimized for positioning and minimum weight. His hydration comes from an EZ Gains-Hydro BTS integrated system, which eliminates traditional water bottle cages that could compromise aerodynamics. Every gram on this build earns its place.

Why This Strategy Works (The Physics of It)

Weight Wins on Climbs

On a 1,244m climbing course, reducing weight is more critical than enhancing aerodynamics. Time trial bikes shine where cyclists maintain high speeds on flat terrain — aerodynamic drag plays a significant role there, giving TT bikes their edge. But on a climbing-focused course like Nice, gravity becomes the most significant force. Every additional 100 grams on a bike translates into extra effort over 1,244 meters of ascent. Riddle's 700–1,200 gram weight advantage is therefore not cosmetic — it delivers tangible time savings on the climbs.

Aero Efficiency Without the Trade-Off

Switching to a lighter road bike doesn't mean sacrificing aerodynamics. The Nexar FRD's aero tubing, combined with Vision aero bars and ENVE Pro wheels, retains a significant portion of those aerodynamic benefits. On fast descents where speeds can hit 60–70 km/h, this edge allows Riddle to maintain speed without excess effort. In practical terms, athletes spend far more time climbing and descending on mountainous courses than grinding flat sections where a TT bike dominates.

The aerodynamic losses on the few flat sections are far outweighed by the gains in climbing and handling everywhere else.

Descending Confidence as a Competitive Advantage

One aspect of Riddle's strategy that's hard to quantify but immensely valuable is the confidence he carries on descents. Road bike geometry — more upright and stable — helps riders navigate technical sections with ease. Combined with hydraulic disc brakes that perform consistently regardless of conditions, Riddle can tackle Alpine descents without hesitation. In a championship where every second counts, descending even marginally faster because you trust your setup can be as decisive as any aerodynamic optimization.

What the Pro Equipment Trends Tell Us

A Broader Shift in Strategy

Riddle's choice is part of a bigger trend in professional triathlon. Just before Nice, another pro, Kristian Blummenfelt, was spotted testing the new 2025 Giant Trinity Advanced SL — sparking its own debate on racing setups. These cases point to a clear shift: professional triathletes are prioritizing course-specific equipment choices, moving away from a one-size-fits-all mentality. The days of "just pick a TT bike, it's always faster" are fading.

Equipment decisions now account for elevation profiles, descent technicality, wind exposure, and road surfaces. Manufacturers have taken note — the growth of the aero road bike category, exemplified by the Nexar FRD, reflects a genuine market need for race-specific machines.

What Age-Group Athletes Can Apply

You don't have to be a pro to think like Riddle. If you're targeting a 70.3 with significant climbing, ask yourself these questions before defaulting to your TT bike:

• Is my course climbing more than 800m? If so, weight matters enormously.
• Are there long, technical descents? Ensure you have reliable hydraulic disc brakes.
• Am I spending more time on climbs than flat sections? Focus on weight over aerodynamics.
• Does my current TT setup give me confidence on tricky terrain? If not, better handling may save you minutes.

Practical takeaways for age-groupers:

• Analyze your course's elevation profile before selecting a bike.
• Consider aero road bikes as viable options for hilly courses.
• Invest in disc brakes and electronic shifting for superior performance on technical descents.
• Integrated hydration solutions reduce both drag and weight significantly.

Even at more accessible price points, many strategies Riddle employs — minimizing weight and using wide-range cassettes — are available to athletes who choose gear deliberately. Our triathlon training gifts guide can help you find upgrades that align with your race needs.

Complete Component Spec List

For those interested in the full tech breakdown, here's every piece on Riddle's Nexar FRD:

Category	Component
Frame	Felt Nexar FRD
Chainring	cSixx 56T
Cassette	SRAM 10-33
Crankset	Shimano Ultegra 170mm (power meter)
Chain	Shimano Dura-Ace
Rear Derailleur	Shimano Dura-Ace Di2 RD R9250
Base Bar	Vision aero bar
Spacer	3D-printed custom
Cockpit	Tetsuo Masamune
BTA Mount	TriRig BTA Pro kit
Brake Calipers	Shimano Dura-Ace BR R9270 hydraulic disc
Front Rotor	Shimano RT MT900, 160mm
Rear Rotor	Shimano RT MT900, 140mm
Shift Levers	Shimano Dura-Ace Di2 ST R9270
Wheelset	ENVE Pro (100mm front / Pro Disc rear)
Tires (TBD)	Continental GP 5000 TT TR or Pirelli P Zero Race
Saddle	Wove TT/Tri saddle
Hydration	EZ Gains-Hydro BTS integrated system
Total Weight	~6.8–6.9kg

Key Takeaways

What Jamie Riddle's bike setup teaches every triathlete:

1. Course profile beats convention. The Nice course's 1,244m of climbing fundamentally shifts the weight vs. aerodynamics equation. Know your course before you select a bike.
2. Weight savings compound on climbs. A 700–1,200g advantage over standard TT setups offers significant time gains across 4,100 feet of elevation.
3. Disc brakes are essential for technical descents. Hydraulic discs with a 160mm front rotor provide the confidence and safety that traditional rim brakes simply cannot deliver on Alpine courses.
4. Aero efficiency and road geometry can coexist. Riddle's balance permits competitive advantages in climbing and descending without significant aerodynamic penalty.

Source: triathlonmagazine.ca