I replace the chain on my all weather IGH bike once a year or so, which is about every 5,000 miles. Takes about 20 minutes and costs $7. I never clean. measure or wipe down the chain, just spray silicone spray once every other month or so. Replaced the rear sprocket once at about 25,000 miles, am now over 50,000 miles and the chain-sprocket combo still works like clockwork.