American Taylor Knibb is pedalling to an impressive lead midway through the bike section of the Ironman 70.3 women's world champs in Taupo

Knibb is powering along at more than 47 kilometres an hour...and leads Switzerland's Imogen Simmonds by more than two minutes, with the UK's Kat Matthews in third.

Hannah Berry is the best of the Kiwis - five and a half minutes down in 12th, with compatriot Rebecca Clarke in 17th.

Series leader Jackie Hering is struggling...currently in a lowly 26th place - almost 9 minutes behind the pace-setter.