Re: chain tensioner modification
I started out using the stock plastic roller... That ended up dieing after about 100 miles. Then I switched to a gear out of an old derailleur, which was already in bad shape. And that was eaten within about 300 miles. Now I have a skateboard wheel. I used a high speed drill as a lathe, and a file to cut a groove. I have only had the wheel on for about 100 miles, but it is holding up just fine, no wear, quiet, and should last the life of the bike.
I also have a KMC420 chain now because the to-small rollers on the stock 415 chain were starting to seize (yes, I kept it well greased). But the sticking rollers probably didn't help eating up the derailleur gear.