AJA 23: Tubeless Sealant Deep-Dive

AJA 23: Tubeless Sealant Deep-Dive



Silca has a new tubeless tire sealant out, and Hottie and Fatty have some questions about it. A whole hour's-worth of questions, in fact. From the recycling aspect of it to setup strategies to keeping carbon fiber from clogging your valve stem, this is the episode that shows what happens when Josh starts thinking about plugging up holes.


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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  • Andrew

    I am a roadie who has become tri-curious, and after a season of triathlon using my road bike with clip-on aerobars, I am considering getting a TT bike with a disc wheel. I love my 28mm tubeless tires, but cannot find a disc wheel that follows the rule of 105 when 28’s are installed. Given there is no trailing rim edge, does the rule of 105 even apply to disc wheels? Or does the width at the hub mean that 105 is more than satisfied

  • Tom C

    Did I hear correctly on this podcast that it is NOT recommended to use CO2 cartridges for latex tube inflation? I just switched to latex tubes a few years ago – don’t have tubeless-ready wheels for my road bike yet – and carry latex tube spares and cartridges.

    Should one carry butyl for their spares and/or switch to a portable pump for roadside tire changes?

    Btw, the innovation in CF in tubeless sealant sounds compelling. I was not keen on adding more hassle with the current situation of road tubeless sealants, but this sealant with the replenisher sounds like something I could live with.

    Thank you,
    St Louis

  • Robert N.

    Paris-Roubaix had a notably high amount of tubeless tires and punctures this year! What is going on? Was it burps on the cobbles, a lack of sealant or something else?

  • David Lilja

    Arguably Paris-Roubaix is the toughest test of man & machine on the Pro circuit especially when wet. I’m interrupting watching a replay of the ‘21 men’s race with 2.7kms to go now, before later today the ‘22 2nd la’femme edition and tomorrow the men.

    When the question was asked in the podcast about who or when the new Silca’s sealant may have first been used the answer was ‘I can’t say’.

    Josh, when you get back home (or onto your laptop in Europe) can you pretty please tell us now if you will ever be able to tell us who used Silca’s new sealant? I’m not the only one waiting for such critical news of an apparent breakthrough in this such relevant technology, especially for this anniversary of a tubeless tire win at Roubaix. We understand about contracts …but!

    Could any of the future tech you will inevitably be working on be contracted with teams/testers so that in a shorter time-frame you can relay such important and details new tech to us mere mortals? Or maybe tires & sealants themselves after inflation pressures have now become just as competitive in the Pro peloton as once-upon-a-time on the F1 grid. Moscon did perhaps lose because of a puncture last year; were Ineos using tubes?

    Perhaps you wish for a second but more annoying catch phrase after “that depends!” has become your first (which we wish we weren’t be-grudgingly forced to agree with, of course ‘it’ always depends). “I can’t say!”, we’d rather hear this said Josh, “I can’t say …yet!” At least give us some hope! :)

    I’m cheering for Cobrelli, w’duya think are his chances with 2.7 to go now?

  • David Lilja

    Could ‘The’ Replenisher (thanks Hottie) alone work with any real world benefit if added directly through the valve inside latex, TPU or other tubes for some degree of added puncture resistance or air loss benefit? Could dry and separate carbon fibres be added first through the valve if the fibre content is too low to be useful for these benefits using Replenisher alone?

    Silca’s 2 sealant products would appear to have a neutral effect upon latex and rubbers more generally, and what about with TPU? A lightweight spare tube (of any type) could be pre-treated and also replenished as needed.

    Many existing wheels can not meet or exceed the 105% rule with larger tires than an ‘old school’ 23mm version at best and especially with newer tubeless sizes.

    Josh, you have said that no-one is putting any further development $s into non-tubeless options. Perhaps this could allow continued use of such wheelsets including tubular and those using rim brakes too which have all been abandoned for wider disc only variants in recent times.

    We all understand about economic constraints upon bicycle companies to sell new product! How do we continue using these existing products to lower our future carbon footprints from the need for more high energy production to create more ‘modern’ replacements and therefore save the scraping of such ‘classic’ equipment and benefit from marginal gains thinking responsibly at the same time?

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