Expect to replace exhaust systems around every 36,000 miles. Variable, of course - but that is my experience having owned 2 ST1100 Pans which have covered a total of 130,000 miles.

Current Mileage 70,100 miles

Complete exhaust system replaced at 68,550 miles with Honda Original Front Pipes / Collector and both rear silencers. This exhaust system has done just 1,500 miles.

Rear Left, Pannier removed. New exhaust	Rear Right, Pannier removed. New silencer.	Right view.
Left view.	Looking through the frame from above the seat through where the petrol tank is housed, down onto the collector and silencer clamp bolts.