G.3.1. Material and shape of cone rings
- For steel and titanium frames, use cone rings made of aluminum.
- For aluminum frames use cone rings made of hardened steel with a knurled surface on the conical part
- Cone rings from model year 2010 and later have 18 milled grooves on the backside of the cone ring, that engage into grooves milled into the backside of the housing. There is a second type with a knurled surface. Don't mix up milled and knurled cone rings!
- aluminum and steel cone rings of different width and with milled grooves on the backside
- aluminum cone ring with smooth surface (for knurled gear housing) and steel cone ring with knurled surface (for knurled gear housing) and a slot to match the bevel of the bottom bracket shell perfectly.