smashndash

I wanted to say that stan's generally is not considered a good sealant for road, but some people are as touchy about sealant as they are about chain lube. Glad it worked.

AndrewJB

I was doing my spring maintenance this weekend and decided to remove and clean out the sealant from my GP5000TL tires. I discovered the sidewall weeping issue for these TL tires (vs TR as discussed by OP) when I had soaked one tire overnight in water in an effort to help loosen the dried sealant. After I had remounted the tire I pumped it up to set the bead (clean & without sealant). The picture shows all these water bubbles on the sidewall from absorbed water being forced through the sidewall. The video is me brushing some spit on the tire to confirm the air weeping. Both sides of the tire all around had this condition.

I have used these tires for 2 years with CaffeLatex sealant and never had a problem with losing air. In fact, they would usually last longer that my other bike with tubes. In the two years I topped off the sealant 3 times so I figured it was time to clean them out. Refilled each wheel with 30ml CaffeLatex and they have been holding air no problem, just like before.

So, maybe try the CaffeLatex sealant if the sealants you have tried don't work.
Maybe I have a bad set of tires, otherwise it just seems to defeat the purpose of tubeless if the tires are made with this amount of sidewall air seepage!

Barry2 

So there you have it.

Removed tire on the rear.
Scrubbed Rim.
Scrubbed inside of tire to remove Stans No Tubes
Reseated tire and added 35ml Orange Seal Regular.

Overnight it lost only 10 PSI.
I suspect this might improve after actually being ridden.

I have officially switched Sealants.

Barry

If you.ve reached this post and wonder what's going on. Please go read the TLDR summary I added to the original post #1
Thanks

JAS3000

Thanks for this thread. It's been super helpful. I've been using Conti GP 5000 TL with no issues for a long time. I have a long race coming up this weekend, I saved the Conti 5000 S TR tyres for the event, I knew they were TR and not TL, but was stunned at how much air I lost during some easy rides this week, and then overnight huge loss (like others, about 40psi). I assumed I did something wrong, and was using Stans. I happen to have just received Silca's new sealant, so going to swap to that today.

I personally think Conti should have been a lot more clear about this, given that your sealant switch has made such a big difference, so as to be the difference between functional and non-functional tyres. I'm sure someone will go on about Conti not needing to say anything, but the reality is that the bike tyre industry, and tubeless in particular, is still all over the place in terms of standards, and this product has clear and unexpected limitations that are required to be mitigated by the end user, in order to ensure the product functions in a manner that's consistent with Conti's presence in the industry.

Barry2 

JAS3000
Now that I’ve ~100 miles with Orange Seal in them, they lose a coupl-a-three psi overnight.
So about the same as the TL version.

Only thing I don’t like about these tires… I contacted both Conti and the USA importer and heard shi nothing!
Quite disappointing for such a brand.

Barry

GhostRider62

I am only losing 2-3 psi overnight too switching from Endurance to Orange Regular, but still lose an unacceptable amount during a long ride. (as posted previously). I am going to switch sealants yet again from Orange regular.

scottfsmith

I'm doing well with the new Silca stuff on my TRs. Not that I tried anything else.

The only problem I had was the rim tape blew out at 2AM this morning.. got woken up with this whoosh sound. Glad that didn't happen on the road, all the air was out in a few seconds. These are Roval CLX rims taped in the factory.

Fredo76

I guess tubeless tires work better when the rubber is half an inch thick. Tubes seem to be wonderful devices for containing sealant. With replaceable valve cores, effective sealants, and tubular double-sided tape instead of glue, it seems to me that running tubeless is now more of a hassle than sew-ups are, and maybe as much of a hassle as sew-ups WERE.

I'll be trying tubeless 48mm tires on my brother's bike soon. Maybe I'll love 'em. We'll see.