I've seen similar conversions to service-only, and I'll just say that service was a loss leader for us. We never found our service department to be profitable on service alone. Some of it was the complexity of the type of bikes we services (high-end, aero-focused bikes) and some of it was because service pricing has largely been subsidized by healthy margins on parts sales.
The service-only shops will never be anything more than cozy lifestyle businesses. And a few of those that own service-only shops actually live in the business to make ends meet.