Ask Josh Anything #12

We are happy to report that we continue to seek questions Josh is unable to answer, or at least unwilling to try. We regret to announce that we have so far failed, in spite of the fact that in this episode we expanded our universe of acceptable questions to include how to make electric scooters more aero. Josh was, in fact, distressingly excited by this question.

We (or more to the point, you) also asked questions about:

  • Silca's new Super Secret Lube: To be honest, we spent a few minutes asking about this lube, and then about half an hour talking about lubes in general, the importance of lubing, and the proper way to lube.
  • Pressure calculator vs manufacturer specs: What should you do when the Silca tire pressure calculator gives you one pressure recommendation, but the tire manufacturer gives you a much higher minimum recommendation?
  • Pressure calculator and tube type: Does the way you keep the air in your tire (latex tube, butyl tube, tubeless, tubular, etc.) matter in the pro tire pressure calculator? If so, how much? And if not, why not?
  • Tire hysteresis and contact points — we have some followup questions for Josh about his recent conversation with Path Less Pedaled.

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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  • Michael Rand


    Is there a difference between tubular glue and the double sided tape?

    There should be less hysteresis plus easier to change on the go for Ironman triathlon.

  • Matt

    Hi. For years I was always disappointed that no matter how much a bike cost and no matter how good the bike shop that sold it they would deliver it without cleaning off the anti-corrosion packing grease and applying proper chain lube. Then a very knowledgeable mechanic told me that Shimano chains are actually packed with an advanced, long-lasting lubricant that could be ridden with as is, and for some reason Shimano chooses not to publicize this. If Shimano is one of your sponsors maybe you can find out what is actually supplied with their chains. Thanks.

  • Ron

    You spoke of the fear of hydrogen embrittlement in the metal of the chain if one left a chain in degreaser, which would seem from what little I know needs to be acidic. Then you suggest that ultrasonics would be better. Has anyone looked at hydrogen embrittlement after sonic action? Many chemical reactions are accelerated by ultrasonics, the field of sonochemistry is dedicated to this. Another concern is that sonication can cause pitting of metallic surfaces due to the energy release of the collapse of cavitation bubbles. So since so many people have used ultrasonic baths to clean chains it suggested that it is not a problem for the times in the bath? So back to the initial question is the embrittlement caused by corrosion reactions? I would love to learn more about this.

  • Blair

    Hi Fellas,

    Quick question in light of the latest pod and Josh’s recent videos on chain cleaning and waxing/lubing. The Zero Friction site seems to suggest that one should “break in” a new chain for 50-100 kilometers before the first deep cleaning and application of wax/lube of choice. Meanwhile, it sounds like Josh recommends cleaning and lubing a new chain before one even puts it on the bike. Can you clarify which is preferred and/or if it particularly makes a difference? Finally, have you sent a sample of the Super Secret to Zero Friction or another source for independent testing? Just purchased my first bottle and looking forward to giving it a go.



  • Johann

    I’ve played with the “pro” Silca online pressure calculator – specifically replicating the info shared in the Part 4B blog, 25.8mm tire (using 26mm), new pavement, 190lb total system weight. However the calculator is returning a value about 18psi lower (low 90s) than the charts shown in blog 4B (110psi for New Pavement). What is the reason for this?

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