Cycling home today, I was flagged down by someone pushing their MTB near Lancaster gate, he asked if he could borrow my pump, which I produced, only to discover that the adapter bit that converted it from Presta to Schraeder was jammed together, and we couldn't reassemble it in schraeder mode. I do hope he found someone with a pump and got home ok. He said he had 10km to get home with a flat front...