I have the Projection components 4-way adjustable raising links on the Z and have tried them in all positions which, if I remember rightly, are +5mm +15mm +25mm and +35mm.

Anything from +15mm upwards at the rear tended to shift too much weight forward causing the front end to tuck in tighter corners and be a bit over-sensitive to loading (on brakes and throttle), the higher the rise, the more pronounced this effect becomes.

As it happens my front end sits 10-15mm higher than stock now (due to internal fork mods) and I run the links at +15mm and the balance is about right. Effectively this means the is no differential between front and rear as they have both been raised the same amount. So fitting fork preload spacers giving a slight lift at the front could be balanced with a similar lift at the rear on your bike, but I would have said +10 to +15mm would be more the order of the day?

I would suggest that a 30-35mm rise would only be necessary, and give balanced geometry/handling if you had fitted a USD or other fork conversion up front. However, links are cheap and quick to change so no harm in trying it out? You might find you like the weighted front-end feel and more twitchy/sensitive steering? It also depends very much on whether you are running a stock shock or not (I'm not). The OE shocks go saggy very quickly and a lift of 30mm at the rear might be a handy (and cheap) temporary fix to get things level again. Also, on an X which I have no experience of, it may be different? Depends why you want to raise the rear...

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