I ride a LWB recumbent and have had the same experience. I ride 2500-2800 miles a year strictly on paved trails and I clean/lube the chain once a week. I replace the chains (2) every winter, even though the chain checker doesn't yet show sufficient stretch. Good chains (SRAM PC 990) and good drivetrain care are only part of the reason. The fact that you can't stand up on the pedals has a lot to do with it too. bk