I brought a set of Tufo 31mm extenders (these were the longest sold) with my S3 lites. They only just seem to fit through my 404’s which makes it difficult to get a good connection with the pump. Can anyone recommend any longer extenders which place the valve core at the top (i.e. not the Zipp kind), so I can put in sealant during a race?
Thanks
This doesnt answer your question but last summer I packed everything for a triathlon BUT my extenders. Those two little pieces of metal almost cost me competing in the race until I found someone who let me borrow theirs…five minutes before race start.
Ive got the TNI 40mm valve extender on my 404 which moved the core and leaves about an inch showing, plenty of room to attach a pump or remove the valve to put the goo in.
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Nytro sells the TNI’s in 40mm and 50mm lengths. Note: that measurement includes the threads, so the effective extension is 30mm and 40mm respectively.
Vecchio’s Bicicletteria in Boulder, CO, sells 32mm (effective) Continental extensions.
I have to screw a couple together for my 606’s. 
Mojoe