Picking The Ultimate Bike For The Ultimate Endurance Race

Here at Pro Bike Supply, we get stoked on riders pushing the absolute limits of what’s possible on two wheels. Jacob, our local legend, madman, and long-distance enthusiast, recently embarked on taking on the Unbound XL race in Kansas. Calling this race "crazy" is an understatement—it’s a 356-mile, unsupported ultra-endurance gravel race that is basically certified crazy people shit.

The Unbound XL is tough enough in good conditions, but this year, torrential rain and peanut-butter mud made an already brutal race almost unbearable. When the conditions turn sideways, picking the right bike and dialing in the build can literally be the difference between crossing the finish line and not making it there at all.

Jacob, being a self-proclaimed bike nerd, chose the all-new Salsa Flyway for this massive undertaking. (We honestly should do bike checks on his other bikes because they are most definitely different and cool). He started with a stock Medium-Large Salsa Flyway with an Apex Eagle AXS build, but he didn't stop there. He made some highly calculated, key upgrades to reduce weight, maximize reliability, and optimize performance for the unrelenting Kansas mud.

Here is a breakdown of the dream endurance build:

• ENVE SES G45 Wheels: Built to perfectly balance aerodynamics with the durability needed to handle both fast-rolling gravel and aggressive chunk.
• Schwalbe G-One RX Tires (700x50c): With mud being a clear probability, maximizing tire volume and choosing a tread pattern that clears debris quickly made this the obvious choice.
• SRAM Red Crankset (165mm): If you are going to make a single upgrade to your drivetrain, the crankset is arguably the most beneficial. It shaves critical grams where you will feel it the most.
• SRAM XX1 10-52t Cassette: Perfect for maximizing the benefits of low rotational weight and giving Jacob the ultimate bailout gear for those steep, muddy pitches.
• Wolf Tooth Aero Chainring (46t): It seems counterintuitive for a gravel setup, but the aero chainring was the clear choice—not for aerodynamics, but because the solid face prevents thick mud from sticking and packing up around the drivetrain.
• Shimano XTR PD-9200 Pedals: When a race forces you to hike-a-bike through 20 miles of mud, there are very few pedals on the market that can compete with the mud-clearing capabilities of XTR and still work flawlessly when you clip back in.
• Profile Designs Aero Bars: Almost 30 hours on the bike means you’ll desperately want to find a fast, alternate position to get comfortable and relieve pressure on your hands. This is the perfect use case for aero bar extensions.
• Almsthre Large Frame Bag: Because Unbound XL is totally unsupported, you have to carry all your own tools, food, spares, and extra clothing. This bag ensured Jacob had room for everything he needed to survive.

So, how did the bike hold up? Jacob powered through the brutal conditions, proving that the Flyway was the ultimate weapon of choice. Out of the 300+ starters, he was one of only 59 resilient riders to actually finish the race, pushing through to an absolutely amazing 23rd place in the Men's Open.

We'll let Jacob's own words sum up the madness:

"2026 Unbound XL 350mile gravel race complete! Ended up finishing in 23rd Men’s Open with a finish time of 29 hours and 52 minutes… the longest I’ve ever ridden my bike and most likely the longest I will ever ride my bike 😂

This race almost felt more like a spiritual journey with everything I / everyone racing went through. Turns out ‘good vibes’ can take you a long way! I met so many strong and awesome people, rode through a thunderstorm in the middle of the night, walked through probably 20 miles of mud, rode through another hail storm, and dealt with probably 5+ different mini mechanicals. Stubbornness is far more important than fitness at these ultra events! Ended up burning 15,500 calories, so I’m gonna spend the next week eating every sweet in sight!

Extremely grateful for @probikesupply for helping me get this bike setup on such short notice before this race. This was only my 3rd ride on my Salsa Flyway from them but it was the perfect setup for the day!"

Massive congratulations to Jacob on an unbelievable achievement! If you are feeling inspired to build up your own dream gravel or endurance rig, reach out to our team. We're always here to help you get the perfect setup for your next big day in the saddle.

Explore The New Salsa Flyway