I adjusted a drive chain on my motorcycle to a correct slack (20-30mm), tightened axle nut and locked adjuster bolts, checked the chain slack again - everything is correct, then I do a test ride, just first-second gear. After that I checked the chain and it was tight as a drum, the set slack was gone. Ok, I do the procedure all over again and adjust to the correct slack. After I take the bike for a test ride again, I check the chain and it is now too loose. So it appears like the slack changes after the ride, even though adjusters didn't change position and remained on the same reference marks.
Why doesn't my bike keep the set chain slack, but changes it after a test ride.