Nordictrack S15i vs S22i: Comparison & Differences | Reviews: Both are upright bikes from the same manufacturer and share the same collection. These bikes were created to match the attractive and hip models of bikes on the market. Which of the two options is best? Over ten years, I've been in the fitness industry and have had the privilege of trying out many bikes … [Read more...] about Nordictrack S15i vs S22i: Comparison & Differences | Reviews