Ask Josh Anything #011

Josh, Hottie, and Fatty are back with all the bike-related questions too nerdy to be asked (or answered) anywhere else. In this episode, we tackle:

  • What lessons from track racing can be applied to singlespeed mountain bike racing?
  • All else being equal, are fewer spokes more aero?
  • Is a matte finish on helmets faster than a gloss finish?
  • What are the fastest patterns for tire treads?
  • What marginal gains are there to be had when racing your indoor trainer online?

Got a question you’d like to ask? Text or leave a voicemail at the Marginal Gains Hotline: +1-317-343-4506 or just leave a comment in this post!

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  • Opikbidin

    Are recumbents and fairings marginal or significant gains? Consider recumbent and handcycling is older than the first bike by 120 years.

    Can we have recumbents and fairing diacussion in aerodynamics, speed and comfort? From Velo Torpille ( a faired upright bicycle) of Etienne Bunau Varilla in 1913 and Mochets velocars that rocked the track world and broke the hour record in 1930s, including breaking 50 km in one hour with a fylly faired recumbent, with Francis Faure as the main man in the spotlight

  • Ron

    I was using the new SPPC (Silca Pro Pressure Calculator) form and a thought came to me. What would happen if all other things being equal (ie bike frame, wheel etc) but all you did was change from a 25 700c tire at optimal pressure to say a 32 mm 700c at optimal pressure. What is the rolling resistance difference. I know tread can have an impact so for this thought experiment I am suggestion the same tread profile? There is an inertia difference due to tire weight but what else comes into play?

  • Joao

    Is there any chance a dirty frameset and wheels can replicate a dimple-like effect on its surface, and be more efficient? Please justify my lazyness.

  • Justin

    Great podcast. It’s rare to find someone with Josh’s knowledge that is still so open to learning and new ideas.

    I’d love to hear Josh’s thoughts on a few areas:

    Has he ever come across any data on how BB stiffness effects actual speed, especially in seated steady-state efforts?

    Pretty much all wind tunnel, rider+bike, data shows drag reducing as yaw increases. Outdoors this doesn’t seem to happen! The opposite, data from outside suggests effective CdA increasing with yaw?

    There are exceptions of course. Selective shelter along a race route, traffic effects due to wind-shifted turbulence etc

    What kind of accuracy and precision differences have you seen from various pumps at track pressures, say 170-180psi?

    Keep up the great show, loving the YouTube vids too.


  • Ritchey

    Hi all,

    love the podcasts. I have one question regarding your “trilogy” on Hour Record. It seems, that you skipped the years between Boardman’s Superman Record in 1996 and the attempts, that start in 2014 when the Unified Rules came into application. Were there no gains, no interesting attempts under so called UCI hour record rules between 1997 and 2014? Thanks a lot. Keep on doing this great work.

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