Latex inner tubes updated

[Retrorockit]

So what I've learned so far from this-
1- The foaming action of the Caffelatex had some value by coating the whole inside of the Latex tube every ride, air loss was at a a manageable level. I'm not aware of any other foaming sealant.
2- The Caffelatex destroyed every Latex tube I used it in. Specifically it attacks the glue joint between the Latex tube, and the Butyl stem. Often from the outside in. It also attacked the glue joint between the tread and casing of my Rene Herse handmade gravel slick. This is from inside an intact Latex tube. The fumes are seriously corrosive to glued joints. I supposed patched tubes would have this issue also.
3- While doing this test a sealant for TPU tubes became available. The easy way out- TPU tubes with TPU sealant. I tried Caffelatex in those too. It doesn't stick to them. But weight and rolling resistance still favor Latex tubes. Especially ultralight tires that can bleed sealant out the sidewalls if run as tubeless..
4- All the sealants that settle to the bottom of the tire seem to have the Latex air loss problem.
5- Glycol sealants look interesting. Non drying, long lasting, won't freeze. They tend to use higher doses than other sealants. But Latex tubes seal better than Butyl, so in my case I will go with a standard 1ml/1mm tire width ratio. I already have the tubes and the sealant so that's what happens next. Specialized specifically states for use in Latex tubes.

6- I use a Park Tool TSI-1 tire sealant injector. I discovered it won't fit down the hole in the Michelin Schrader valve. I found a Sunlite tube with the same issue. It seems some of the stems have added metal inside to make them stronger. It's not an issue with just air going in. If you use this tool check your tubes for this. A PITA to have to drill them out (#26 .147"). The Vittorio tubes were OK. No issues with Presta so far.

 

[Woz]

Schwalbe 14A.

 

[Woz]

And a track pump.

 

[Woz]

With an (optional) gauge.

 

[bikeworkshop]

Schwalbe 14A.

By "extra light"
they mean
"only a bit heavy"

 

[Woz]

By "extra light"
they mean
"only a bit heavy"

* COUGH * Extra Extra Light FFS. They are what is written on the packet. +/- 4 grams. Which is essential.

The lower lever XL - only one Extra = Schwalbe 14 is targeted to poor unrefined people commuting at a whopping 120 grams.

Good for a winter bike though.

I suspect it's all from the same process / extrusion but one as batches of less rubber and a bit more QC for racer boys.

 

[Retrorockit]

OK I guess i should clarify why I'm interested in doing this project.
There are 2 things about the Rene Herse Extralight tires. Light weight is of course a given, and simple enough to understand and measure.
TPU tubes can be used if that is the only goal. I have one in the front tire that's giving no problems at all. But the ultimate goal of the ultralight RH tires is low rolling resistance by having a very supple casing. The 2 options for not giving any of that back are tubeless sealant. But the Extralight tires are known to have issues with sealant leakage through the sidewalls, and blowing off the rims if they aren't very precisely dimensioned (my 20 y.o. 24 spoke Mavics are not).
The other option is Latex tubes. As light and fast rolling as tubeless, but with a learning curve of their own. I'm still learning.
The notion of sealant in tubes has been working very well for me in the Urban Ebike environment. As in no flats using that system.
The testing done by the Triathlon guys is interesting in that sealant works very well in Latex tubes. But leaving it in there causes other problems due the chemical or even water damage to the Latex tubes. But they did reveal the existence of Glycol sealants, which in the case of Specialized's latest 2bliss version they state is compatible with Latex tubes. I was able to locate some of the previous Airlock version, so that's up next.
The postmortem on the water based Latex sealant is the water makes the Latex tubes pucker, and the sealant glues the puckers into permanent wrinkles that lead to leaks, which the sealant tries to fix but ultimately fails. So no more Latex sealant testing for me.
When I went to buy the Airlock at the Specialized dealer they tried to discourage me from buying it because it was "special". I asked why it was "special"? "Because it's for use inside tubes".........

 

[Retrorockit]

So the Airlock sealant is isnstalled. I went with 3 oz. dose. They say it coats the inside of the tube to prevent leaking down. I injected it into the new tube, and coated The whole inside. They also say it doesn't "puddle".
I found that after a month the Latex tube was sticking to the inside of the tire, and the rim. As delicate as they are I suppose breaking the tire down to fix flats repeatedly might not be such a good idea.
So hopefully I have a permanent sealant, that might allow a permanent installation of the Latex tube. This would match my experience with the Ebike.

 

[Retrorockit]

The 24 hour pressure drop was from 42psi to 31psi. This is pretty much the most efficient rolling resistance range according to RH. Not great, but certainly useable for a day or 2 of riding. I never did a bare Latex tube install, so IDK what's normal there on a large low pressure tube.
I used Stans plastic tubeless rim tape. It keeps the latex tube up out of the rim holes. Except the one next to the valve stem. Starting the tape beyond there would help, but an extra layer of plastic masking tape there works also.
I have one more Latex tube for the front. I'm going to give it little more time before I make that move. But I'm definitely looking forward to the full gravel racer supple tire experience on my vintage 26" XC bike. Weight weenies usually fret over a few grams here and there. But most MTBs on the trails here are wide rim 29ers. So I'm saving 100s of grams everywhere. If I can get the reliability I'm used to this will be a lot of fun.