I changed my chain at 27,000 miles. My front and rear sprocket were perfect, but I don't wheelie or do burnouts, and I clean my chain and sprockets every few hundred miles without fail, and lubricate and check the chain adjustment every few hundred miles too. I can understand the theory of changing sprockets and chain at the same time, but upon inspection, if the parts do not show wear, why spend the $$$. I have almost 7K miles on my new chain and it is performing great.