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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Hey, I’ve been listening to these for a while, just thought of a question. I’m a randonneur, and typically rando bikes have a large handlebar bag in front for gear. That’s never been my style, but I saw that Jan Heine is claiming that actually these big bags in front are somehow more aero. Now, he’s clearly knowledgeable, but – how can that be? A big rectangle in front is the opposite of aero, right?
Question on best location for a mini pump bracket. Downtube or seattube bosses? I just unboxed a Tattico and the bracket is going on my commuter bike.
Hi guys,
Love the show. I hope you are all keep healthy and safe.
My question is a small one. Would you think that chainring bolt covers would have a negative performance impact?
I mean, something like this, without covers:
https://scontent.fsyd3-1.fna.fbcdn.net/v/t1.0-9/p720x720/35229374_1949187128484838_480917645730775040_o.jpg?nc_cat=105&nc_sid=110474&nc_ohc=7AWdW1eCylwAX9Fnzrs&_ncht=scontent.fsyd3-1.fna&nctp=6&oh=88425f3677f2b32d27b3c58962e57486&oe=5E9F30D3
Compared to adding covers for aesthetic reasons, like this:
https://pbs.twimg.com/media/DP9_OuLXUAEVGrI?format=jpg&name=4096×4096
And this:
https://absoluteblack.cc/images/katalog/72/absoluteblack_ultegra_6800_duraace_9000_bolt_covers3.webp
My mind tells me.
1) There will a weight penalty. Although ever so slight.
2) There would be an aero penalty as there is simply more “stuff” spinning through the air during each revolution (the A in CdA).
It is David asking. Last question I asked (about black being cooler at over 23kph) you started calling me Greg or something :-)
Keep up the great work!!
Thanks.
Hi guys, just a follow up to my last question: one item that I do not recall Josh talking about is something I will call tire squirm for lack of a better term. It came to mind while riding my fat bike which is the extreme case. That is if the tire pressure is lower and runs well on a poor traction surface once you hit pavement or another good traction surface the tire starts to self steer (squirm). Now to the real question, in something like a criterium where there is a lot of cornering and accelerating, is there a different tire pressure scenario taht may mean having a bit more pressure since the tire is the last part of the power transition system to the road, one might think that stiffer is better in this case and the just rolling along (ie constant speed) CRR is maybe less important?
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
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