Ask Josh Anything #006

The ongoing "Ask Josh Anything" series is back from Summer vacation and we've got a fun — and surprisingly informative — set of questions for Josh, including:

  • What marginal gains are made by following the TTT instructions in a pre-TdF video by Team EF?
  • When you've got a tailwind, is it better to still make yourself as small as possible, or should you sit up and try to take advantage of the wind behind you?
  • What's going on when the dish changes the first time a tire is mounted on a new wheel?
  • Some riders claim their bike feels faster and lighter on climbs when they move their bottle to their jersey pocket. Is there any merit to this, or is the effect in fact the opposite? Or neither?
  • FFWD claims to have made the fastest wheel ever. Is it possible to legitimately make this claim?

All this and an in-depth discussion of what happens to your aero-ness when you grow a beard (with a side discussion on types of beards), in 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? 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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  • Nick

    Cyclocross question. Not sure if it counts as a marginal gain if you aren’t using the best tech – which would be tubulars. But for clinchers, is tubeless or latex tubes the way to go?

  • Rustin R Gramm

    Regarding beards and Aero: a few years ago specialized put the beard to the test in their tunnel. It showed less than a watt of difference over 40K, so pretty nominal. i suppose if you havea full mountain beard, the difference could be larger. thank you

  • Martin Gibson

    Why are tire manufacturers not making 23mm tubeless tires? The new minimum (e.g. Conti GP5000TL, new Schwalbe Pro One) seems to be 25mm, which seems likely to cause aero losses and handling problems in high yaw conditions.

    Some time ago, you published the ‘rule of 105’, in which “the rim must be at least 105% the width of the tire if you have any chance of re-capturing airflow from the tire and controlling it or smoothing it.” (I understand why this is, but won’t repeat it here).

    According to my calculations, a 25.0mm nominal tire (measured on a 19mm internal width rim) will expand to 25.9mm on a 21mm internal width rim, such as my HED Jet Plus. That’s 104%. :-(

    A 23mm nominal tyre (again measured on 19mm internal rim) would expand to 24mm, giving 112% rim/tyre ratio – much better.

    Is this a market decision (everyone wants wide, because ‘wide is good’), or is there a technical reason for doing this?

  • Brett

    During hot gravel endurance races my shins/knees/biceps will become crusted in gravel dust. Basically anything that is a leading edge in the wind & sweats eventually develops a thin crust of gravel dust.

    I always use a little bit of water to clean this off because I think it inhibits cooling. CONSENSUS is not to waste water by pouring it on yourself & a coat of gravel dust doesn’t inhibit evaporative cooling from sweat anyhow.

    This isn’t really Josh’s bailywick but what does he think? Does a Crust of Dust inhibit evaporative cooling?

  • Nick

    When are Silca going to bring out a stand alone pressure gauge – separate from a pump?

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