In this Asahi article about a bicycle-powered knitting machine, the following sentence appeared:
[1足分]{いっそくふん}を[編]{あ}むのに[10分]{じゅっぷん}[程度]{ていど}こぐという
It takes about 10 minutes of pedaling to knit one pair (of socks, he says).
Is it [1足分]{いっそくふん} or [1足分]{いっそくっぷん}?