I was looking into changeing the chain, front and rearsprocket on my 01 S4 and wanted a little advice on the best setup. I am deffinitly changing the front sprocket from a 15T to a 14T because everyone that has done it has liked the low end performance. My Question is the rear sprocket should I stay with a 37T (stock) or go up to a 40T. I need a 525 HV chain and the only sprocket that moto wheels offers in that size is 37T or 40T. If i go to a 40T sprocket will the bike have to much low end?