What is the lifespan of a sprocket on a mini-excavator?

The lifespan depends on operating conditions: a machine working in abrasive environments will wear its sprocket much faster than one operating on softer ground. Generally, on a heavily used mini-excavator, the sprocket should be inspected every 1,500 to 2,000 hours and replaced as soon as the teeth show asymmetrical profiles or visible material loss.

Which mini-excavator brand is the most reliable?

Caterpillar, Komatsu, Volvo, and Kubota are frequently cited among the most reliable brands in the mini-excavator market. Beyond the brand, it is the regular maintenance of the undercarriage — sprocket, track, rollers, idler wheel — that largely determines the machine's longevity.