Got it now !lotus7 wrote:Still, how is the disk fitted ? No "normal" disk bell?strad wrote:That's exactly what it is.Could be for a wheel speed sensor, or something along that line of gadgetry.
http://www.f1technical.net/articles/2
The disk bell pushes over the geared flange , the gear teeth "drive" the bell. The wheel, when fitted holds the bell/ disk in position , when the wheel is off , the caliper prevents the disk/bell from falling out