Ask Josh Anything #17

No matter what topic — modeling, bifurcation, the smell of lubrication, chain innovation or even power loss due to new tire nubbies, tube width decisions, or even PFAS chemicals — the Marginal Gains crew can count on insightful questions from our listeners. We put all of these subjects to Josh in this latest "Ask Josh Anything" episode of Marginal Gains.

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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  • Travis Verhoff

    Hot waxing is going to be your best option. The heat isn’t going to be hot enough to melt the wax, but it will help keep all that sand out of your chain!

  • Neil Winkelmann

    On new tyre nubbies: My snow and ice tyres (Continental Contact) have REALLY pronounced and numerous whiskers when new. You can actually hear them in the wind when riding. They probably matter, but the tyres are so slow rolling anywhere, I’m not much bothered!

  • Garth

    Hi Josh,

    A little while ago you mentioned that you polish the rear cog on a track bike before an hour record attempt. Since then I have been looking at the chainrings and cogs on my own bikes. I notice that some brands and models are more shiny than others. And I wondered; are there gains to be made by polishing chainrings and/or cassette on an otherwise clean and optimized setup.

    While we’re on this topic, do you have an opinion on DLC or otherwise coated chains? There are versions from KMC & YBN, neither are shiny. Should we also be looking for a chain with a polished like finish?

    Look forward to hearing your thoughts.


  • John Simpson

    Dear Fatty, Hottie & Josh,

    First of I’d like to thank you for putting together such a mind-expanding show.

    I have two questions that I’d like to put to you:

    The first concerns the optimal start-line tire pressure for a long day of multiple mountain pass climbs and descents, as in the queen stage of a grand tour. And I’d like to ask you to consider how this optimal pressure would vary according whether the event is in high-summer (with a likely 5pm finishing line temperature of around 35C) or late summer (when it would be nearer 20C), in both cases following a chilly start at around 10C.

    [I have in mind two specific European cyclosportives: the Marmotte Alpes which normally (i.e., no Coronavirus) takes place at the beginning of July and finishes 1100 meters higher than the start, and the Oetztaler Radmarathon which takes place at the very end of August and is a pure circular ride ; ]

    My second is whether there is a systematic difference in rolling resistance between folding-bead and wire-bead tires. I have in mind a specific example, and am raising the question on the supposition that if there is indeed a difference in that specific case it could carry over to other tires in general.

    The specific case: I use 16” Schwalbe Kojak tires [I ride cyclosportives using a Brompton folding bike]. The kevlar-beaded version weighs 197g ; the wire-beaded version weighs 230g, of which the wire by itself accounts for 49g [I stripped a tire down as far as possible then burnt off the remaining rubber]. From visual inspection they are identical except for their folding/non-folding nature. I would be surprised if the kevlar beading on the folding tire weighs as much as 16g, which leads me to wonder if this tire also has some additional strengthening in the casing, which would presumably increase its rolling resistance.

    Again, a big thanks.

    John Simpson

  • Tom

    For the next AJA I’m wondering if ya’ll can go into the effect of lacing patterns on aerodynamics and spoke count. (Or if you have covered it, could you direct me to the episode?)

    Example 1: Same rims, same spokes, same hubs, same tires, same spoke count. One is laced radially, the other is 3x on both sides. From a “high level” do the crosses disturb the airflow in a meaningful way?

    Example 2: Same rims, same spokes, same hubs, same tires, same cross pattern, different spoke count (20 vs 28). Again, from a “high level” is there an aero penalty?

    Example 3: Same rims, same spokes, same hubs, same tires, same spoke count. One is laced symmetrically one is laced 0x/2×.

    I’ve spoken to my LBS mechanic and wheel builder about this and their answers have been holistic: balance durability, weight, feel, etc. I totally get that (and believe in that) for everyday wheels but what about for wheels dedicated to the Local Monthly TT World Championships of the Universe.

    Hmmmmm. Like most thing’s I’m guessing that within the first few sentences Josh will say, “Well, that depends . . .”

    Thanks so much ya’ll!

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