Tubeless tire question

[dgasmd]

Recently bought a used mtb. Has tubeless tires that were pretty old and worn. Bought some new Conti tires and tape and put them on. Added about 50cc of Stan Non-Tube látex too. Inflated the tires with an air compressor, they “popped” into place, and seemed to hold pressure without audible leaked to the 35 psi I inflated them to. 3 days later sitting in my garage, I noticed the front completely flat and the rear with less than 1/2 the original pressure. Te-inflated then only to find the same a couple of days later.

Is this a common and standard thing with tubesless?? If not, suggestions on what to look for!

[Miller]

Assuming the tyres are meant to be used tubeless, I'd review the quality of your tape job and also the seating of the tubeless valve on the tape. Little splits round the valve base can be troublesome.

[Dan Gerous]

Also, when putting sealant in, don't just inflate them and call it a day, I always give them a spin, shake them a little with the wheels horizontal, on each side. This allows the sealant to get everywhere inside the tire to seal any little microscopic holes, any little gaps between the beads and the rims... But, tubeless tires usually lose their pressure over time a bit faster than butyl tubes so you might want to check pressure before most rides.

[TobinHatesYou]

I lose around 2psi per day at road pressures. More than a light butyl tube, less than a latex tube.

[dgasmd]

Well, tires are certainly tubeless. I’d hate to dismount them and redo again as these tires are true to Conti (will loose a finger or 2 getting in place)!! However, this is almost completely deflating in less than 3 days. No obvious audible leaks, but will try water/bubbling before I dismount t them. Thanks for he advice so far

[Orlok]

Well, tires are certainly tubeless. I’d hate to dismount them and redo again as these tires are true to Conti (will loose a finger or 2 getting in place)!! However, this is almost completely deflating in less than 3 days. No obvious audible leaks, but will try water/bubbling before I dismount t them. Thanks for he advice so far

Maybe that the valve isn't tight enough.!

[Fisherfreerider]

Taking the bike for a ride after setup will do wonders for making them seal better, even if it is just up and down the street.

I would re-inflate and take it for a ride.

[ms6073]

Maybe that the valve isn't tight enough.!

Or not correctly seated onto the rim bed as the OP did indicate that new tape was installed. There is also the possibility that rubber seats on tubeless valves are worn cracked in which case no amount of tightening will yield a good seal.

[mattr]

Also, conti tyres have that horrific release agent on the tyres, did you scrub the inside before fitting?

[IrrelevantD]

If the tires don’t have a butyl later, it could be that they didn’t seal up fully and you’re losing air through the sidewalk. I had similar hapen with a pair of CX tires. This can easily hapen with any tires that are tubeless-ready or “require sealant”.

After you get the tires seated on the rim, sealant added, and tires aired up, make sure you shake them really well, working your way all the way around the tire. I typically use a little extra sealant the first time I mount a new tire, especially in high volume tires [ie: not road]

[bm0p700f]

Most cont tyres are not tubeless compatible. They only released a tubeless model this year, the first for about 7 years

Conti tyres take time to seal up. It took my non tubeless X kings a whole week to hold air.

[Mr.Gib]

As mentioned above, you definitely must do the whole swirl the tire around thing. You have to get the sealant to coat everthing inside - tire, rim, etc.