The bolt I was describing is a shoulder bolt. This is a schematic of a similar Suntour rear derailleur from http://www.disraeligears.co.uk You will see that the top pivot (shoulder bolt) has both a thin washer between the top of the upper pivot bolt and another thicker washer below. This is identical to my setup except the upper pivot bolt threads into the dropout bracket instead of being held on by a nut in the back. With a washer on the end of the upper pivot bolt, it seems to me that the upper pivot won't be able to move the same as mine. I have also read that the Suntour Mountain Bike derailleurs had the upper pivot stationary for rigidity. Do you thing it would harm anything to file down about .75 mm so the shoulder bolt will extend out farther?