Alright, sorted it - switched my QRs from PlanetX fancy Ti/carbon external cam things to proper Shimano internal cam QRs. Squeal gone. Now terrified of how bad/loose the PlanetX ones must have been.
Side effect of making my descending a million times better - just felt more secure all round. I now eat hairpins for breakfast.
Alright, sorted it - switched my QRs from PlanetX fancy Ti/carbon external cam things to proper Shimano internal cam QRs. Squeal gone. Now terrified of how bad/loose the PlanetX ones must have been.
Side effect of making my descending a million times better - just felt more secure all round. I now eat hairpins for breakfast.