70% may also be a bit too much bias towards the front for the rear engined FZR. Not saying that turning too much whilst still braking isn't also the cause but that it's probably a combination of the two. Unless your having trouble with the rear locking up and trying to bring itself around then I'd look at something more along the lines of 65%. Typically my FZR setups are around 63-65%, with no engine at the front the front tyres will be more likely to lock than say in the XRR so more rear bias should be used in general.