Ask Josh Anything #004

Q&A Episode 4 -

We didn't set out to turn every other episode of the Marginal Gains Podcast into the "Try to Stump Josh" game show, but at least 2/3 of the hosts of the show are glad it worked out this way. In this episode, we ask Josh what he thinks of Zipp's new MTB rims, puzzle over why the GoPro is so non-aero (and how to mitigate that non-aero-ness), discuss aero cranks and why they aren't any bigger of a deal than they are, talk about why it's faster (sometimes) to ride the white divider line, wonder why ceramic bearings don't (usually) turn back into sand, detail the steps for figuring out CRR in the field, explain why heavier riders descend faster, and — believe it or not — more. Enjoy this new Q&A episode of the show that makes a big deal about the little things, and how those little things can be a big deal.

Got a question you’d like to ask Josh? 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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  • Michael D

    The question and discussion regarding the action camera got me thinking about accessories. My question to Josh relates to the best mounting location for the Silca Tattico mini-pump. Does Josh recommend to mount the pump behind the bottle on the down tube or seat tube from an aerodynamic point of view?

  • Chris

    Hi guys,

    Random question about chains and gears and reducing friction.

    Is there anything to be gained from polishing the drivetrain? (Perhaps with a tumbler and different media?) One of the ideas behind waxing chain protocols is to remove any metal shavings/etc, seems like polishing could also help (so long as it wasn’t “too smooth”) I believe the Premier (Tactical) optimized chain uses Isotropic Finishing. I hear plenty about waxing and some about coating drivetrain parts, but nothing about polishing.

    Keep up the good work!

  • Josh Poertner

    Thanks Alee,
    You are on it… the key is to develop small scale un-damped or minimally damped suspension that can essentially add to the compliance of the system without robbing it of energy. So the Lauf fork is a good example of a design that essentially reduces impedance losses similar to a much larger volume tire. The Ergon and Redshift are close, but both have some inherent damping that starts to complicate things as that begins to rob energy. There is also so much that we don’t understand here yet, but working on it!!

  • Frederic CREMERS

    Great!, I can’t help but listen to your comments, looks like it’s a topic that hasn’t (yet) been hijacked by the marketing depts of the industry companies we love so much (at least not as much as lightweight aero and stiffness of the bike itself).

    (Not marginal) Cheers

  • Josh Poertner

    Thanks Kar-Soon,
    We answered part of this in the Q&A 5 that we just recorded today and will be live next Tuesday, with more to come on the hour record in a few weeks!
    Thanks so much for such insightful questions!!

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