95 Ninja 500, 19000 miles. After I ride for a while and come to a stop, seems like there's a shudder in the chain. I don't know if its after riding hard or just after riding for a while. The rear wheel is aligned with the factory marks on the swing arm. I haven't tested it with string yet. The chain and sprocket set is the original. Doesn't look to need to be replaced yet. I had the rear wheel off a while about 500 miles ago to replace the rear tire. The shop mounted and balanced the tire and I put it back on. How much slack should the chain have? I don't recall how much I have but it may be a little tight. Do you think its a misaligned rear wheel or its time to replace the chain and sprockets or tight chain or something else not mentioned? Thanks!