Tubeless tyres

[Ironfist]

My daughter has a tubeless 26'er MTB. She does'nt ride the bike very often. The tires keep on loosing air. It also does'nt want to inflate with a pump. I took it to LBS to repair it but still keep on loosing air. Any advice? I want to repair it myself but I'm not familiar with tubeless tires.

[David Marshall]

No single answer.  It could be going flat for any number of reasons.

 

Firstly I would check that the tires are the tubeless type.  There should be some indication saying "tubeless", "tubeless ready" or UST on the tire itself.

 

As the tire is now flat I would carefully remove it from the wheel.  Scoop out the sealant and store it in a container.  Wash the rim and check that the rim tape is not damaged or lifting.  Replace it if it is.

 

Then make sure that the valve is correctly seated.  I do this by standing with the rim on a rag on the floor and pressing the valve into the rim with my right thumb as hard as I can while tightening the valve nut with my left hand as tight as I can get it without using any tools.  

 

Refit the tire to the wheel and inflate it.  You need a compressor for this and most likely will have to remove the valve core to get enough air in quickly enough to seat the tire.  Once seated quickly replace the core and inflate to about 4 bar.  Try to find where air leaks from.  Air escaping from the valve hole in the rim often comes from air leaking into a spoke hole and not from the valve itself.

 

If things look good remove the air and core and inject the sealant through the valve stem.  Re inflate and the best is to go for a short ride to disperse the sealant.  Ride the next day as well.

 

Top up the sealant every 4 months.

[Ironfist]

No single answer.  It could be going flat for any number of reasons.

 

Firstly I would check that the tires are the tubeless type.  There should be some indication saying "tubeless", "tubeless ready" or UST on the tire itself.

 

As the tire is now flat I would carefully remove it from the wheel.  Scoop out the sealant and store it in a container.  Wash the rim and check that the rim tape is not damaged or lifting.  Replace it if it is.

 

Then make sure that the valve is correctly seated.  I do this by standing with the rim on a rag on the floor and pressing the valve into the rim with my right thumb as hard as I can while tightening the valve nut with my left hand as tight as I can get it without using any tools.  

 

Refit the tire to the wheel and inflate it.  You need a compressor for this and most likely will have to remove the valve core to get enough air in quickly enough to seat the tire.  Once seated quickly replace the core and inflate to about 4 bar.  Try to find where air leaks from.  Air escaping from the valve hole in the rim often comes from air leaking into a spoke hole and not from the valve itself.

 

If things look good remove the air and core and inject the sealant through the valve stem.  Re inflate and the best is to go for a short ride to disperse the sealant.  Ride the next day as well.

 

Top up the sealant every 4 months.

Thank you very much for your advice David. Will definitely give it a try!!