Expire is not really the right term; but effectively yes. In general a cheque older than six months will be considered stale-dated and will not be honoured. Reference the Canadian Payments Association FAQ.
SKYACTIV is a brand name for a series of technologies developed by Mazda which increase fuel efficiency and engine output. The initial announcement of the SKYACTIV technologies include new engines, transmissions, body, and chassis, which appeared in Mazda products from 2011.
Wahoo Elemnt GPS computer challenges Garmin's supremacy. Once a ride is uploaded, the Elemnt's analysis is primitive. The Wahoo Elemnt won't dethrone Garmin from GPS computer supremacy, but it should put the tech giant on notice.