They are pretty robust, I have been riding the same presta valves on my mountain bike for maybe 5 years which I ride a few times a week, immense amounts of dry

They are pretty robust, I have been riding the same presta valves on my mountain bike for maybe 5 years which I ride a few times a week, immense amounts of dry silica, muddy dirt, rain, cold, heat. They are serviceable too. If you find it isn't sealing you can disassemble and clean the sealing surfaces, replace the locking oring or nut etc.