This S7 bolt was the perfect fix for a triple ring Cooks Bros Racing Crank arm! Have you stripped out the threads for the mounting bolts of the granny ring? CBR generally has deeper thread holes than the std. 17mm deep chainring bolt can reach. I stripped out two of the mounting holes but when I measured with my calipers I realized that I could potentially use a 23mm long bolt. Try finding an M8 x 0.75 extra fine thread! This bolt is the best: 23mm and the proper thread! Worked like a charm and with a bit of Loctite I was able to secure the granny ring evenly amongst the five chainring bolts!