Got some old Juicy 5’s with roundagons and they seem to have a slight judder to them. All my other juicys are using G2 rotors and don’t suffer from it. Likely to be the rotor?

Didn’t really explain that well. What I mean is, is this a function of the shape and noticable under heavy braking (far less “round” than the G2)?

Quite possibly, had something similar with my Mono Minis, the braking surface tapers between the spokes, and a change to Shimano rotors with a parallel braking surface stopped it completely.

I’ve tried several different styles or rotor over the years and have concluded that all the fancy wavy, saw tooth designs are fancy tosh!

Round ones are great end of.

Time to buy a new G2 and do some swapping.