So did Abraham Olano. You’re in good company there ;-)

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Since the foam shrinks and sits in the center channel, it shouldn't impact the tire/road interactions. I'd expect zero effect on rolling resistance pre-flat.

They SAY it "shrinks"...but I've also read they SAY that even at pressure, it interacts somewhat with the sidewalls. No way to really know unless you measure.

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http://bikeblather.blogspot.com/

They don't just say it, there's a video showing it shrink significantly under pressure. It will shrink even more in thickness when the ends are fixed end-to-end as they would be when it forms a circle. It'll squeeze firmly into the rim bed. Pushing on the tire bead wouldn't affect rolling resistance, since that area isn't flexing/rebounding. Would be neat to see the demonstration in a circular cube, though.

As they say, "the proof of the pudding is in the tasting" :-)

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http://bikeblather.blogspot.com/

From the Aerocoach testing of sealant volume increases in Crr I can’t see how these foam liners won’t have some impact on Crr. They looked intriguing until I saw that they make it difficult to push TLR tire beads into the center rim channel and require a pliers tool to do so. This may work for some race events where you want to roll in to the finish, but in day to day riding the fail over sequence for me is 1) sealant fills puncture, 2) use plug to fix puncture and 3) pop TLR bead - boot puncture or slice - pull tubeless valve - insert butyl tube. I’m not interested in rolling along on a nearly flat tire:(

With races like the TDF, riders get a flat sometimes they have to ride 5mins+ waiting for a support car to turn up, but riding tubs means they can still hang with the peleton. Is this a reason why a lot of teams are still sticking with tubs? If they flat with a clincher, they could be stuck on the side of the rode for 5mins which means they have zero chance of catching up with the peleton.

zedzded wrote:

Is this a reason why a lot of teams are still sticking with tubs?

This is why.

i assume you've ridden flatted tubies. i have many times. it's a pretty disturbing experience when you're riding them on a descent. riding a flatted tubie is an advertisement for foam liners in a tubeless system.

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Dan Empfield
aka Slowman

haha that's insane

I had a flat during IMWA at 80km, the second tub had a leaking valve, slowly deflating from 80km, I was praying it would hold (Corsa Speed which you can't ride flat) and it did, until 200m from T2 and I managed to just roll in at 10km/hr. I thought my race was done. Never ridden my Conti Comps flat, but as I said earlier saw that guy on Comps at 30km/hr+ with it flat.

Because sealant is on the inside of the tire while this sits on the rim bed. It's more akin to saying that rim tape may add Crr.

Admittedly no. My tubular riding experiences are fairly limited, and I've in general never attempted to keep riding on a flat after noticing it.

I do agree that a foam liner in a tubeless system makes quite a bit of sense, assuming that it actually retains the tire well and doesn't interfere with rolling performance when the tire has air.

Very poor analogy as rim tape has zero volume and sits entirely below the tire beads. We’ll see when they are eventually tested.

But as I outlined, they are a limited case solution that will likely cause more issues than they fix. So many TLR users already struggle to simply mount a tire or break one tire bead on an already mounted tire and these will just make that process even more difficult.

Aah yes, the "legend of Abraham Olano" keeping tubulars "alive" for decades...sigh...

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http://bikeblather.blogspot.com/

i haven't flatted to the degree that i need to change a flat in the field in 4+ years on road/gravel tubeless setups. How little sealant are the mechanics putting in these? Or do they gash their tires in ways that i've never done?

I see so many flats and hear complaints about flats so much (former roommates were pro tour mechanics) but can only fathom that they are skimping like crazy on sealant or not even using it.

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36 kona qualifiers 2006-'23 - 3 Kona Podiums - 4 OA IM AG wins - 5 IM AG wins - 18 70.3 AG wins
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If you watch or listen to the Andreas Klier interview I did last year, we indirectly talk about this technology for a bit.. Andreas discussing running the entire team tubeless at the Tour without sealant.. and we had been using these inserts of various sizes/shapes and durometers for almost a year at that point and we work around the topic being careful to not mention this directly!
https://www.youtube.com/watch?v=D1sKJwU63Nw

I will say that so far this year we've had 4 occasions where riders have finished races with flat tires they did not realize were flat..to the riders, the liner at worst feels like a softening tire but nowhere near a flat one. The one downside is tire removal.. it's nearly impossible with the insert in place, which isn't an issue for the team, we just cut the tires off with wire cutters.

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I imagine the pro tour riders are going waaayyy faster than what Vittoria states below speed wise. So, do you know if they can they be ridden faster without damaging rims or are the pro tour riders trashing rims while finishing up the race?

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If you lose that pressure, however, Vittoria says the foam once again expands to fill most of the tire volume, not only allowing you to limp home up to 50 km (31 miles) at up to 20 km/h (12 mph) without too much risk of damaging your wheel, but also acting as a sort of mild beadlock to keep the tire from peeling off the rim.

Yeah, gotta consider rider weight:

Pro Tour riders maybe, but your average American cyclist probably not.
.

What is the aversion to sealant?

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36 kona qualifiers 2006-'23 - 3 Kona Podiums - 4 OA IM AG wins - 5 IM AG wins - 18 70.3 AG wins
I ka nana no a 'ike -- by observing, one learns | Kulia i ka nu'u -- strive for excellence
Garmin Glycogen Use App | Garmin Fat Use App