As some may recall in late August @24k miles I replaced the rear sprocket and chain on my 2006 XT225. (The sprocket was 45T stock size but aftermarket brand.)
Instead of another O-ring chain I bought two standard (unsealed) chains. Chain #1 was replaced in late October @26k miles. It measured 60.375" long. Chain #2 new measured 60" long. So it stretched 0.375" or 0.63% in 2k miles. Chain #2 was replaced today (late December) @28k miles. It measured 60.25" so stretch was 0.25" or 0.42% in 2k miles.
* While mileage was similar between these two intervals road/trail conditions were very different. So this isn't really a "fair" comparison. Still some might be interested in these measurements anyway.
* In both cases the "other" chain gets washed in gas (kerosene not readily available). Then after drying soaked in 30W oil for at least a week. Then drip dried before reinstallation.
The experiment continues. Going forward I'll keep a close eye on chain and sprocket wear during round #2 for both chains. I can swap sooner (ie, every 1k miles) if needed. Meanwhile, Plan A is to keep playing leap-frog between both chains every 2k miles.