ChosenOne wrote on 09/25/17 at 1:19am:
I just tried tubeless on my 650b super gravelly road bike wheels. WTB Byway with Hunt rims... They held air w/o sealant for 2 hrs. When I put sealant in I can see where some was was forced out around the bead. I would bet that WTB rims with WTB Tubeless ready tires may do a better job of staying aired up without sealant.
(You need to Login or Register to view media files and links) 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.