Exploding Rotors: why you do not drill

[Duncan Thomson]

> > I would challenge anyone to find pictures from a reputable site or brand
> with discs which have
> > been drilled in anything other than a symmetrical fashion...
>
> http://www.harley-davidson.com/PR/MOT/2003/03_model_enlarge.asp?locale=en_US
> &bmLocale=en_US&market=US&family=Softail&model=FXSTS&num=1

ask and you shall receive...!
I guess that proves the point!
does anyone have a better picture which shows the entire disc..?

> Drilled rotors do not have to have their holes in any clearly repeating
> pattern.  They only need to have the center of mass be at the center of the
> rotor ("balanced").

For balancing, yes, but for thermal and stress loading, any irregular hole positioning will result
in stress concentrations which _will_ weaken the disc.
Obviously in the case of HD, this was not the deciding factor, and it must be vibrations or
resonance that prompted them to use their rather unconventional pattern...

thanks for the info, very interesting, just still trying to get my head around this issue...

cheers
Duncan