At 148k miles my 1979 R65 started developing roll-on / roll-off bucking. At 174k miles I ran a thread here (see "Roll-on roll-off bucking") to discover its cause and found that it was lash in the drive train, especially in the final drive due to wearing teeth. I replaced the final drive with one with very few miles on it. The lash went away but 5k miles later the lash is back. Is it because the teeth in the final drive and in the wheel are a matching set and both should be updated at the same time (get a new wheel or repair the splines on it)? Or has some other component started to wear, like the drive shaft spring and coupler? What do people with high-mileage bikes do about drive-train lash?