Originally Posted by
Charles Wahl
Would adding some toe-in using (or making, by filing normal ones) the kind sold by René Herse help squealing any?
Probably not.
The "squealing" is a result of stick-slip, which is mainly a function of the resonant frequency of the arms and the amount of excursion; if the excursion is large enough to have the pads alternate between stick and slip at a frequency both resonant and audible you hear squeal. Having pads not parallel to the braking surface only makes it more likely that the friction between the pad and the rim will vary as the pad first touches the rim with only part of its surface, then more-and-more as greater pressure is applied.