Kiwi Multisport is a sporting goods store in the Hampidjan/Nelrig car park at 98 Vickerman St in Maitai, Nelson, with a Google rating of 5.0. Its name suggests a focus on multisport gear.
A good sporting goods store helps you buy the right gear, not just the dearest. For multisport and endurance events, that usually means gear that suits more than one discipline, such as running shoes, cycling gear and swim or paddle kit, so say which event you are training for and what your budget is. Footwear is the best example: try shoes on late in the day when feet are a little larger and ask staff how they fit for your kind of running or walking. For equipment, ask about fit and sizing before price, since the wrong size spoils the sport. Check the return and exchange policy, and watch for end-of-season sales if you can wait. Regulars shop ahead of the season and call ahead to check stock.
For anyone in Nelson training for an event, Kiwi Multisport on Vickerman St is a local store to ask.