[RPM]

Oh yeah, you will still need to get a bottle of locktite for these, too.
If you are looking at the larger utility units, try to get a driveshaft model and you won't have to worry with the chain. The chains are usually mounted with the help of a tensioner, but not always. I have found some units actually loosen the chain when you sit on it, much less ride on it and those will need the aid of a tentioner for sure just to keep the chain on and prevent sprocket damage. Pay attention to the swingarm mounts as well as the suspension on the models you look at, as that will the most used part of the unit.