AJA 28: When are 2X drivetrains NOT worth aero, chainline and aero costs?


It's a no-topics-barred Ask-Josh-Anything episode of Marginal Gains, and (as usual) Hottie and Fatty get their own burning questions to the front of the line. Hottie desperately wants to talk about F1 porpoising and its connection to Hopf bifurcation. Josh accomodates. Fatty overheard a rocket scientist proclaim he wouldn't trust a repaired carbon fiber hardtail for technical mountain biking and now Fatty's scared about whether he's OK to ride. Josh reassures Fatty with the sage advice that "it depends." We then dig into actual listener questions about what kind of Ti alloy Silca uses when 3D printing, the pros and cons of 1X vs 2X drivetrain setups, and...how one might marginal gain a triple stroller in order to set a world record 10K pushing this pram. As always, this AJA episode's a great mix of thoughtful, serious, practical and silly. Don't miss it!

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  • Ron

    I am wondering if this idea could work? Most if not all current bike computers have an accelerometer in them. Could this be used to detect hysteresis and then used to determine optimal tire pressure based upon the road surface and the minimization of the vibration/ movement? an app on the device or maybe even in a phone app? where the vibration is minimized at the user?

  • John Semmelhack

    A few months back, Dan Bigham (on a different podcast) mentioned that Reynolds number decreases as altitude increases, thereby increasing drag…and “taking back” some of the aerodynamic gains due to lower air density at higher altitudes. Can Josh wade into the weeds a little about Reynolds number, altitude, and hour-record attempts?

    Side note: the first ~23 minutes of today’s pod (F1 racing stuff) are the only minutes of any episode that I skipped through. A 1-2 minute F1 racing sidebar is fine by me…more than that is too much!

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