Marginal Gains Cycling Podcast, Presented by Silca

While listening to Paige Onweller answer our questions, we found ourselves wishing we could be more like her. Wishing we had her organizational skills, her critical thinking, her ability to adapt quickly. Paige has the tools to be the kind of Marginal Gainer that makes us think, "I wish I was more like Paige."
Paige's focus on details started well before she ever saw a Gravel Race start line. She was a collegiate runner and after that, had a career in medicine. But like we've heard from many runners, her sport led to injury which led her to the bike. At first, her riding was for fitness while she healed. But then she discovered how good she was, and so did others. Namely team Twenty-Twenty Four. They brought her on board to do Zwift racing and Time Trials. Before she knew it she was on a start line in Nebraska at Gravel Worlds. Then her career in medicine was put on hold as Paige took her detailed approach to the Life Time Grand Prix. 
Josh and Paige's partnership started this spring in the wind tunnel. The two of them got together for a focused approach on aerodynamics and women. They made some very interesting discoveries which we talk about in this show. Ever thought about waxing hair? You will after hearing them discuss Paige's aero bun.

Josh sinks his teeth into questions on turning road spray on a frame into aerodynamic information, Argon gas in tires and deep, carbon wheels for XC mountain bike racing. 
We also talk about Fatty's successful Everest challenge – the Marginal Gains that worked and the ones that didn't. And we get into some new happenings with Silca.

A favorite topic on the Marginal Gains Podcast is rolling resistance, also known as CRR. It is one of the cornerstones of this show. While we have interviewed aerodynamic experts who have devoted hundreds of hours to CdA, we have found very few who have made CRR their passion. Tom Anhalt was an early guest but we can't think of another since. That changes with this episode. 
John Karrasch makes a living from bike fittings. But John has made a name for himself through his tire testing. Using the Chung method, John has been putting tires to the test to see which ones live up to the hype. In just more than a year, he has amassed an impressive database covering just about every brand you can name. The beauty of John's work and results is he shares it with all of us at no cost. 
In this interview, John shares his early beginnings with the Chung method, how he has refined his testing, and what some of the key learnings have been. The only thing between your bike and the surface you ride are your tires. John is one of a few who has been trying to quantify just how much power it takes to keep those tires rolling.

It's funny how tubeless freed is from tubes and years later some of us turned to putting something else in the space between rim and tire. Namely inserts. Most of them are foam and a real struggle to install. Then there's OPTIS: The Odyssey Tire Pneumatic Insert System. Cool acronym that basically means "inflatable insert." The people at Odyssey will be quick to say OPTIS is not a tube. While it does press up against the sidewall when inflated, it's job is just like a foam insert: to prevent pinch flights. OPTIS weighs significantly less than a foam insert, and its behavior is adjustable. We spoke with Jacob Hinton from Odyssey on this unique product that recently gained notoriety during a spring classic. 
Up next is a look at radial tires for bikes. 32-inch wheels have garnered most of the buzz in 2026, but radial tires are also making waves. Two big tire makers have jumped into the space and made claims of enhanced grip for gravity-style riding. A third company, Delium, has also been developing radial tires. We hear from this lesser-known maker about how tech works and its potential in the bike space.

Our 50th Ask Josh Anything! That's a lot of questions and answers and "It Depends." Thanks for hanging with us to the mid century mark.

On the Q&A agenda this episode:
The perfect padding for aero armrests. 
Tire inserst for Unbound
Breaking in tires for best CRR
The right gears for an Everesting
Narrow flat bars for Leadville
Gravel wheels on a road bike and the rule of 105