He is currently director of online fashion company Onceit and ASX-listed Adairs.
Torpedo7 is currently lead by Tim Edwards, the chief executive of the group's electronics retailer Noel Leeming. Torpedo7 and Noel Leeming were previously heavily linked but now operate independently.
"This change will allow Tim to focus on our growth opportunities in our very successful Noel Leeming brand and to ensure its continued success," a spokesman for the company said.
Grayston said West's appointment as chief executive of the outdoors and sporting retailer would allow for "dedicated focus on the brand" during an important stage of its growth.
"Simon is well used to working in businesses undergoing growth which is part of the current focus for Torpedo7," Grayston said.
"In the past year Torpedo7 has opened four new stores, taking its total to 18 plus one franchise in Wanaka. It is currently in the process of transforming the brand with key focus areas including bike, snow, water, camping and apparel."
Torpedo7 has more than 16 stores nationwide and operates online retailers 1-Day and Number 1 fitness.
The 1-Day business will be added to company digital officer Michelle Anderson's portfolio of group e-commerce brands, which will enable the online platform to benefit from accelerated growth.
Torpedo7 sales were up 6.9 per cent in the third quarter ending April 28.
The Warehouse is in the final stages of developing an e-commerce business named TheMarket, which will launch early next month.
TheMarket is a subscription-based shopping platform and will offer 'rewards' for consumers and influencers active on the marketplace. Interestingly, the lifestyle site does not look to push the company's own retail store brands.
The Warehouse Groups owns and operates The Warehouse, Noel Leeming, Warehouse Stationery and Torpedo7 stores.