This is brilliant. Can I buy some?
Presta valves work ok but there are slight issues. Nothing major, I’ve never had one block or leak, but things can always be improved:
1. They don’t admit that much air which reduces flow rate and can hinder tyres seating
2. The little pip on the end can bend and break off
3. You have to remove the core to get sealant in, and this can be hard when it’s gummed up.
4. Conversely, if you want to undo the pip to let air out you can sometimes remove the core by mistake.
5. Doesn’t always seal that well on the inside of the rim
I love it when a bit of legacy tech is redesigned for the better, and even more when it doesn’t need anything else major to be changed.
EDIT I take it back – forty quid a pair!