AJA #45: Pump Accuracy & Cheap Carbon Parts

Hear why that “psst” when you pull the chuck is just hose air (not lost PSI), how to set smarter pressures for tandems and “big-butt” weight splits using a bathroom scale, and what tread actually grips on loose-over-hard. Josh also demystifies analog vs. digital gauge accuracy (and drift) and tackles the carbon-on-the-cheap question—when a bargain is fine, and when it’s a dentist bill waiting to happen.

Marginal Gainers are familiar with Best Bike Split -- the website where using rider data you can forecast a finish time on a specific course. It has been a great tool for years for amateurs and pros alike. Josh has frequently referenced BBS on the show. Fatty and Hottie have discussed it on their Leadville Podcast. But we wanted to know what is under the hood. For that we turn to its founder Ryan Cooper. Before Best Bike Split, Ryan was a lot like us: a competitor with the hopes of going faster. Unlike most of us, he's really good at math. His ability to come up with equations and sus out variables gave him the tools to invent Best Bike Split. But the inspiration was more of an experiment -- a story will leave for him. In the interview, Ryan shares what he can about how BBS comes up with its forecasted times. He also talks about some new features he has in the works like factoring in tarmac conditions to better hone in on times.  Ryan also wants listeners to get a taste of BBS and he is extending a discount to listeners of the pod. Use the code MARGAINS25 for a discount and as Ryan says: Race smarter. Ride faster. Win more.

Josh tackles the fallout from his viral “hookless is a scam” comment, clarifies the real risks and physics behind hookless rims, and dives deep into tire pressures, gauges at altitude, and disc wheel aerodynamics.

Australian cycling champ and Grand Prix contender Brendan Johnston shares the races that shaped him, the setbacks that tested him, and an upcoming project that may become his ultimate proving ground.

Lauren Stephens has been easy to spot in both Road and Gravel events; just look for the stars and stripes. She has won three US titles: two gravel and one road. Oh, but there's so much more to her career. How about more than 30 UCI road race victories? She has twice won the Joe Martin Stage Race, the Tour of the Gila and Unbound 100. Lauren has also raced Track, Time Trials, Mountain Bike and Cyclocross. Not bad for a former high school math teacher who wasn't a serious cyclist until 2008.  In addition to reviewing her career, Josh and Hottie also talk to Lauren about her nicknames, her extensive bike collection, that interesting denim vest, social media and her new team -- Aegis Cycling -- and its approach to racing and social justice. 

We take a look at what has become a dilemma for some Marginal Gains seekers and that is optimizing aero, rolling resistance on a tubeless, hookless rim. Josh has an admittedly unpopular take on the subject.  We also get into the aerodymanic idea known as the Magnus Effect. The principle says that a spinning object will develop unequal pressure on either side as it moves throught air. Josh expains how -- if at all -- the Magnus Effect, affects that rotating thing we love; the bicycle wheel.  We also have questions on hot waxing in a vacum oven, the aero cost of external cables, and what is kind of a Silca product shocker: it's Ultimate Shock Pump.  

We know, the title sounds like we're doing an episode about drug paraphernalia, but trust us, it's the (very good) answer to one of many great questions posed to Josh in this latest listener-driven Q&A episode. We get into using the right lube under the right conditions (including super dry moondust mountain biking), aero combos with the Conti Aero 111, TPU tube challenges, and much more. It's a fun and info-packed episode from the show that dares to say, "It depends."

Behind every great cyclist is a great bike fit, which means a great bike fitter. Honestly, we're not sure it’s possible to overstate the gains — or losses— a bike fit can bring. And a startling number of top pros we’ve had on this show trust Barry Anderson of Cyclologic, in Scottsdale Arizona. Barry has popped up on our radar numerous times and for numerous reasons recently. We're excited to share Barry's practical guidance on the why, how, and who of a great bike fit.  

Cécile Lejeune is a rising star in women's pro cycling, but this Frenchwoman (and now Arizonian) is no stranger to speed. With roots in Tri and a number of impressive running records in her native country, Cécile has been challenging herself since the age of 12. A RED-S survivor, Cécile brings an inspiring and candid story to this year's Life Time Grand Prix, where she currently sits in a top-10 ranking. This is even more impressive when you consider that last year she wasn't even accepted into the race. With a love of gravel, tips on where to get married in a hurry, and an outsized helping of wisdom, this conversation with Cécile is not one to miss.  

Fatty is obsessed with mini compressors and so jumps the line in this episode of Ask Josh Anything with several questions he has about Silca's new Elettrico series, Silca's innovative, just-released electric mini pump that is available everywhere (except the US) now. We also got some great feedback/pushback on part of Josh's recent FAQ episode, and a novel new product idea involving tap water from Indianapolis.  And, as always, so much more.