I know that I haven't replaced the chain for the third time on my second trike, a Greenspeed GTO with 27,000 miles on it. It is also on the original chainring but that's mostly because it is a 65 tooth Schlumpf chainring costing $135 to replace. I did replace the rear cassette and the Shimano 105 RD when I replaced the chain the first time. It pays to lubricate the chain frequently. Much cheaper than replacing the entire chain which takes over 2+1/2 standard 112 link chains. I doubt it would have lasted that long if I put excessive force on the chain.