Mick, these are a fairly simple mod.
Their correct name is a tie-rod, and look this
OOO---------
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They tie the swing arm to the rocker arm. The rocker arm connects the shock to the main frame.
Using my make shift picture above, the blue hole is used for each setting.
Blue and violet is standard hieght, blue and orange is 1 1/2" lower, and the blue and red is a whole 3" lower.
This allows the swing arm/wheel to move higher before the shock moves at all.
Simply winding tension off the spring will allow the wheel to move the same, but the shock looses travel and can lead to bottoming out, especially on a comfortably sprung bike.
These do work well, but you might consider trimming off the last loop if you choose not to use it. This will avoid any fairing clearance issues etc... and will look a little neater.
Keep in mind that the front needs to be lowered atleast the same amount to maintain favourable geometry and handling. The side stand will also need shortening. No big hassle, I could do it for you or Mario could probably oblige aswell
. We are both pretty local.
It is far better to dare mighty things, to win glorious triumphs, even if chequered with failure, than to take rank with those who neither enjoy much nor suffer much, as they live in grey twilight that knows no victory nor defeat.
an well you see it goes something like this: