[jannmayer]

I never had a flat on the tires I just replaced. I did pull about 20 thorns from goat heads out, so I'd say the sealant worked really well.

 

[Goran_injo]

True UST tires from the past never needed sealant. They were very heavy though and only few manufacturers made them, and they needed to be certified to standard first. I ran them, and oddly I don't recall having any puncutres regardless no sealant. If I recall, they were north of 800g for 26", which in the time of 400-500g tires didn't fly for most racers.

Then came light tubeless ready tires, which essentially means, ready for more, or less, sealant. No standard applied here.

 

[slimat99]

True UST tires from the past never needed sealant. They were very heavy though and only few manufacturers made them, and they needed to be certified to standard first. I ran them, and oddly I don't recall having any puncutres regardless no sealant. If I recall, they were north of 800g for 26", which in the time of 400-500g tires didn't fly for most racers.

Then came light tubeless ready tires, which essentially means, ready for more, or less, sealant. No standard applied here.

It's been over 20 years since UST. I'm sure we can do better.

I dont' know what the weight penalty would be to add a liner that would prevent air lose? Unless it's double the weight of sealant I would want it. Now if it made the casings feel crappy like UST did that's different. Part of the reason UST rode poorly was back then everything was either singly ply, or DH. Maxxis made a DH UST casing that rode great. It was only singly ply casings that rode poorly because the UST liner really affected how the casing deformed. That liner comprised a good portion of the total weight of yesteryears paper thin casings. Add enough layers to a casing and that UST liner was muted out. I'll bet we could add a liner to today's thicker casings and not even noticed a change in feel.

 

[MSU Alum]

It's been over 20 years since UST. I'm sure we can do better.

I dont' know what the weight penalty would be to add a liner that would prevent air lose? Unless it's double the weight of sealant I would want it. Now if it made the casings feel crappy like UST did that's different. Part of the reason UST rode poorly was back then everything was either singly ply, or DH. Maxxis made a DH UST casing that rode great. It was only singly ply casings that rode poorly because the UST liner really affected how the casing deformed. That liner comprised a good portion of the total weight of yesteryears paper thin casings. Add enough layers to a casing and that UST liner was muted out. I'll bet we could add a liner to today's thicker casings and not even noticed a change in feel.

In the early days of non-UST tubeless ready, the tires leaked like sieves. I tried spraying the inside with that spray rubber. It didn't work. It made the tires surprisingly heavier and as soon as I inflated them, the coating would stretch and let air through. I think this is a solution in search of a problem, but if it is a problem, Slime infused inner tubes are probably as good as anything.

 

[slimat99]

In the early days of non-UST tubeless ready, the tires leaked like sieves. I tried spraying the inside with that spray rubber. It didn't work. It made the tires surprisingly heavier and as soon as I inflated them, the coating would stretch and let air through. I think this is a solution in search of a problem, but if it is a problem, Slime infused inner tubes are probably as good as anything.

Your DIY job with off the shelf products isn't a good representation of what tire companies could do with casing layers.

 

[MSU Alum]

Your DIY job with off the shelf products isn't a good representation of what tire companies could do with casing layers.

No, a better representation would be the self-sealing fuel tanks on an F-16. Those worked great but weigh hundreds of pounds. That's my preferred solution! Anyway, any layer that allows movement of material to fill a hole would probably be heavier, thicker at the tire wall, more expensive and stiffer than a slime filled inner tube. At least with that, you can throw it away.

 

[slimat99]

No, a better representation would be the self-sealing fuel tanks on an F-16. Those worked great but weigh hundreds of pounds. That's my preferred solution! Anyway, any layer that allows movement of material to fill a hole would probably be heavier, thicker at the tire wall, more expensive and stiffer than a slime filled inner tube. At least with that, you can throw it away.

I think the UST liner only weighed 100g or so. I suspect after 20 years we might be able to beat that weight. The whole point of this is to do away with any kind of sealant and just put air in the tire. Sealant filled tube is the complete opposite of what OP and I want.

 

[nobody special]

I have run no sealant in tubeless tires a few times, usually when I run out of sealant during a tire swap but still want to ride bikes anyway. It is a gamble, some tires hold air without sealant for weeks, some tires hold air without sealant for minutes.

Will you get a flat? That is the real gamble.

 

[Nat]

I think the UST liner only weighed 100g or so. I suspect after 20 years we might be able to beat that weight. The whole point of this is to do away with any kind of sealant and just put air in the tire. Sealant filled tube is the complete opposite of what OP and I want.

They were only 100g heavier? That seems inconsequential now in the days of 200g inserts.

I like how clean and maintenance free the process would be without sealant. I like the flat fixing ability of sealant though.

 

[slimat99]

They were only 100g heavier? That seems inconsequential now in the days of 200g inserts.

I like how clean and maintenance free the process would be without sealant. I like the flat fixing ability of sealant though.

I dont' know for sure about that? Just guessing based on the difference between maxis DHF DH UST, and non UST. I would be surprised if a non porous liner in 2024 would need to weigh more than 100g but I really have no idea. That's all that would be needed. TR tires soak up too much sealant as is so honestly I think a dry option might appeal to riders who want sealant too. For all the riders who top off sealant a non porous liner might be a wash after your first top off?