Not a fan of tubeless setups yet...  too many tires are not ready for prime time.  

WTB does TCS pretty well.  Their casings are pretty tight and tend to hold air well.  Lighter tires will be more porous and weep.  

If the tire AND rim are not UST then you can expect to have weeping issues and will need sealant... it's not worth the aggravation unless you are a power ranger.

If wheels and tires are BOTH UST then sealant is not required.

There are still too many variables... for bicycle tubeless tires and wheels.

Ya, most will seat up without sealant but that not the point of using it. The sealant is to plug up small punctures and cuts that happen on the trail. Running tubeless without sealant is just asking to get a flat in the woods.

chickenwyre wrote on 09/22/17 at 4:24pm:


If that's the case, then why doesn't it happen with tubes as well?

I haven't had a punctured tube in more than a decade.

Instead of punctures of the tire casing itself which in my experience is a rare thing around here (maybe not Arizona), I suspect the air is leaking out someplace else. Perhaps around the valve stem or at the bead. And this is why sealant is necessary. If one could prevent these leaks through other means, similar to auto tires then sealant would not be necessary. 

You puncture the tire casing on the trail, you put a tube or a plug in it. Then repair or replace the tire.

Even if sealant was the holy grail of tire repair, I wouldn't want to depend on it for long term repairs to tires that have sustained casing damage.

StevenA wrote on 09/23/17 at 12:04am:


Not yet.

I'm still in the phase of gathering evidence from others experience.
I have talked to a couple of mechanics that know of racers that use no sealant to save weight.
And they have reported these guys have had good results. It seems they seal up the holes, cracks and leakage points in the rims by other means. 

I've got an old WTB wheel laying around I plan to start experimenting with soon. 

Apparently tire selection is important. Some so called tubeless ready tires leak air through the casing.

Here's some reading material if you're interested.

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There are also some high tech, ultra lightweight tubes that are coming on the market as well. But they're are being developed in Europe and I can't find a source for them here.

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This gives you an idea of how popular they are on the other side of the Atlantic;

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IntheBush wrote on 09/22/17 at 11:39pm:



Woah, jimmies have been rustled... 
I would like to know what tires you run and if they are vulnerable to kryptonite?

teamdicky wrote on 09/23/17 at 11:54pm:

Ok..

Again.. Any of you old timers running tubeless without sealant?

2001 or 2017? That is the question.

The Cycle Path wrote on 09/25/17 at 12:53am:


So you're saying that so called 'tubeless ready' tires will not hold air without sealant?

I'm asking if the casing is air tight, or not.

I am aware that so called 'tubeless ready' tires come with an additional layer of rubber on the inside of the tire supposedly for this purpose.

What I'm getting at is, why do UST tires weigh 10 pounds each..? What is it about their construction requires such a large amount of additional weight?

It would seem to me that any tire that could be made to hold air reliably for not much more weight than a standard tire today. At least not anymore than a tire/tube combination.

ChosenOne wrote on 09/25/17 at 1:19am:


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This product has been used on low pressure tires to seal beads for years.

You brush it onto the bead prior to installing the tire onto the rim and it glues the tire to the rim, creating an air tight seal.

I wonder why it wouldn't work on mountain bike rims/tires?

Here's one guys review..

"I use this bead sealer on every tire I install on the ranch. I noticed I have to re-inflate tires much less frequently since I started using this. The most notable improvement is on smaller tires (mowers, carts, etc), but I noticed a difference on all tires, even the oversized tractor tires."

So it sounds to me like, lightweight mountain bike tires have a lot of sidewall flex, which means they burp at the bead when riding which causes air loss in tubeless tires.
The sealant currently being used acts like a glue to keep the bead in contact with the rim (with the resultant liquid excess that constantly sloshes around and adds weight). If that's the case I don't see why one couldn't just glue to the bead to the rim to begin with.

And if it's true that the casings on tubeless ready tires will hold air reasonably well, then why couldn't one just seal up the other areas of potential air loss such as spoke holes and at the valve by other means. 

btalley wrote on 09/25/17 at 3:26am:



I ride 2-4 days a week minimum on local area trails. Sometimes more. CC, Springs, Sherman, etc..

I've got 4 bikes all currently running tubes. Everything from SS, full carbon hard tail, a former French brand single pivot full squish, and of course a late model Spec...

And I can't remember the last time I had a punctured tube. I guess I'm just skilled. 

If somebodies riding style is beating their wheels to death on sharp rocks constantly and/or running ridiculously low air pressures I can see how snake bites could be a problem. But then, even tubeless setups aren't immune to abuse.

I tried tubeless w/sealant. On one tire the valve leaked constantly, changing tires was a royal hassle and I didn't like my wheels being crusted over in that rather nasty sealant. I'm all for ditching the tubes, just looking at other options besides sealant and/or 10 lb. tires.