I was looking at adding a few additional teeth to the rear sprocket to get a little lower end for hare scrambles and some tight trails. Not very Mechanically inclined so not absoulety sure of the result of this. Any good sprockets out there for this application. How many teeth should I add?? Do you need to replace both sprockets at the same time? Thanks for your help Not sure what I would do without this site. You guys are awesome.