Tyre Valve Failures

[Rick]

This is the most serious safety issue that I have read on this forum ! Further investigation is needed as to why these two potentially catastrophic valve failures have occurred. If it was me I would keep the evidence and discuss with Trading Standards or the Ministry of Transport seeking further investigation. The motorcycle press may well be interested in the failures and bring the issue to a much wider audience.
From your photos it appears that the valves are from two different manufacturers, i.e. different designs, and the fact that no one else on this forum reports any knowledge of such defects would appear to point towards the chemical in whatever sealing substance you have used, being responsible for disolving the bonding between the brass insert and the rubber valve outer casing.
From your information such a failure could easily happen when a motor cycle is travelling at a high speed, when a tyre is hot and under most pressure, resulting in an almost instantaneous complete tyre deflation! Not a nice thought.     

[iNCORRIGIBLE]

Thanks,Rik.Will keep you advised. Ed.

[iNCORRIGIBLE]

Hi All to still interested in this topic.Have sectioned a brand new valve to try & understand how it is possible for the smooth-sided,paralle-l walled & barbless brass core of the valve to lose its bond with the rubber sleeve containing it,thus rapidly deflating the tyre.
Please inspect attached pics .

[iNCORRIGIBLE]

Further Pics.

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And again!

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Is this a regular occurence? Ed.

[Rick]

Ed, What is the make of the tyre sealant that you used ? Your valve disection appears to show that vehicle safety is totally dependent on a small amount of glue that bonds the metal valve tube with the rubber casing. I will pay more attention in future to the source and quality of valves fitted to my tyres and will not be using any leave it in sealant.

[iNCORRIGIBLE]

Hi Rick. Have not finished my investigation yet so am unable to give any proven information. Will only comment when I have something factual to report. Thanks for your ongoing interest.
What is really needed are  figures on the number of others who have experienced this failure. Ed.