Many KMC singlespeed chains (including the one pictured above) are primarily designed for BMX racing. BMX pros can put more tension on their chains that track pros because they run a smaller chainring and use longer cranks. I use KMC 510HX (1/8") and 610HX (3/32") chains...never had a problem with them. They seem to last longer than other chains I have tried, including expensive NJS chains. People who criticize KMC chains are clueless. Stay away from the cheap 400 series chains. The 500, 600, and 700 series chains are strong and very reliable.