ROB BRITTON | Record-Breaking Unbound XL | Gravel Aero Suit, Tech & Nutrition

What does it take to win the toughest ultra gravel race in the world?

Rob Britton takes us inside his record-breaking victory at the 2025 Unbound XL, the brutal 350-mile self-supported gravel race across Kansas.

Rob breaks down the key decisions that helped him average over 20 mph for nearly 18 hours and smash the previous course record by more than two hours.

From aerodynamics and nutrition strategy to hydration systems, gravel race tactics, and bike setup optimization, this episode explores how small performance gains compound over ultra-distance racing.

We also dive into the development of Castelli’s first Unlimited Gravel Suit, featuring integrated hydration storage, aerodynamic cargo pockets, and real-world testing at the highest level of gravel racing.

Topics covered in this episode:

•Winning the 2025 Unbound XL

•Gravel racing aerodynamics explained

•Ultra-endurance nutrition and hydration strategy

•Integrated hydration systems in cycling apparel

•Aero gains over 18 hours of racing

•Gravel bike setup for ultra racing

•Racing through the night against Lachlan Morton

•Comfort vs speed in endurance cycling

•The future of gravel race apparel and technology

If you’re into gravel racing, bikepacking, endurance sports, cycling tech, or performance optimization, this episode is packed with insights from one of the fastest ultra-gravel performances ever recorded.

🎧 Subscribe for more conversations on cycling performance, innovation, aerodynamics, and elite racing.

– IMPORTANT LINKS –

Rob Britton

Castelli SOG

CHAPTERS

00:00 Intro

02:38 Quickfire Round

04:05 Chasing Lachlan Morton Through the Night

06:21 Racing History with Lachlan & The Final Catch

07:05 Tactics, Fatigue & Managing the Lead

07:50 Bike Setup, Aerobars & Carrying Nutrition

10:38 Why the Speed Suit Could Have Decided the Race

11:58 How Ultra Racing Has Changed in Recent Years

13:32 First Ride in Castelli's Prototype Gravel Aero Suit

15:25 Nutrition Storage, Hydration & Self-Supported Racing

17:31 Why Ditching the Hydration Pack Was a Huge Advantage

19:35 Aero Performance & Suit Design Details

21:21 Castelli's Aero Heritage & Innovation Story

23:12 Marginal Gains, Ryder Hesjedal & Performance History

23:48 Winter Riding, Future Testing & What's Next

24:18 “The Netflix of Cycling Clothing”

24:28 Outro

– HOST –

Søren Jensen, Global Marketing Manager at Castelli, has worked for this iconic brand since 2006. He usually rides backroads and dirt trails, testing new gear in the Italian Dolomites. If you can't find him there, check the Castelli Headquarters in Fonzaso. Connect:⁠⁠⁠ ⁠⁠⁠⁠LinkedIn⁠⁠⁠⁠⁠⁠⁠

SUBMIT YOUR QUESTION

If you want your questions to be answered on air, be sure to submit your questions by sending us a message on social media or by email to ⁠⁠⁠⁠⁠⁠⁠⁠podcast@castelli-cycling.com⁠⁠

Hosted on Acast. See acast.com/privacy for more information.