Service revenue is more durable than new-bike sales
Look at service department revenue and margin. New bike sales are competitive and seasonal; you fight Trek, Specialized, REI, and online direct-to-consumer brands on price and inventory. Service revenue (tune-ups, repairs, custom builds, fittings) is local-monopoly business. Customers won't ship their bike to California for a $90 tune-up. A shop with 35%+ revenue from service is structurally healthier than one with 15%. Look at service revenue trends and the technician headcount.