# Hysteresis in Marginal Gains

#### Hysteresis in Marginal Gains

Hysteresis is the term for processes that behave differently in one direction than in another. Understanding it is critical for flying, for dampened suspension systems, and for being aero on your bike. Yep, in this episode we'll be making liberal use of analogies that include a Tempurpedic mattress, a rolling tire, mountain bike suspension and a fair number of Hitchhiker's Guide and Top Gun references. Enjoy this episode of Marginal Gains!

Hysteresis loops for inviscid flow in wings:

Got a question you’d like to ask Josh? Text or leave a voicemail at the Marginal Gains Hotline: +1-317-343-4506. You can also email us at questions@marginalgainspodcast.cc, or just leave a comment in this post!

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• Andrew Bolton

Hi Josh, question I’m hoping you could address for next episode. I’m wondering if you can unpack some of the science about helmets, and maybe the marginal gains of safety performance (opposed to aero performance) and how we could be marginally safer. Mips? Wavecell? Really been enjoying the podcast so far, would be great to hear your thoughts on this!

• Robert Chung

As an aside, I’ve done a (very) little bit of work with neonates and NICUs, and had to learn a tiny bit about hi-fi pulmonary flow through immature lungs. I’ve occasionally wondered about respiratory rate and inhalatory volume while I’m on a bike gasping for breath.

• Robert Chung

Nice explanation for why Crr scales exactly like hill slope, so a Crr of .005 creates exactly as much drag as climbing up a hill with slope of 0.005 (i.e., half of one percent). If you’re comparing a tire with a Crr of .004 against a tire with Crr of .005 (for a particular surface) the second tire would be like climbing a hill that’s .001 (= 0.1%) steeper. That may not seem like a lot, but over a 200 km race that’s the equivalent of climbing an extra 200 meters compared to the lower Crr tire.