alpha Racing Rear Axle Nut BMW S1000 RR/HP4 (2010-, 2015-). Hexagonal Nut M24 x 1.5 for rear axle shaft, aluminium Ergal anodised, CNC machined, size 32mm. alpha Racing utilizes state-of-the-art computer automated design and experience in World Superbike Championship and brings you the very best in BMW S1000RR/HP4 billet parts. These special parts are high speed CNC machined, completely milled from high-strength aerospace grade billet aluminium and hard anodized for superior finish, ultra-lightweight and extreme durability.