lowering forks in yokes, what will be gained .
 

Just been giving the bike a check and noticed that the forks sit approx 12mm lower in the yokes than standard setting.
Or put anotherway, the amount of fork tube protuding from the top fork yolk is 12mm more than standard amount if you get my drift.
What effect will this have on the bike on our normal roads etc, is a better option to leave it as is or pu it back to normal setting.

cheers
R

What you really mean is that the forks are pushed up through the yokes by 12mm.

What is gained? Well perhaps it's better to say what effect does it have?

Generally as a rule of thumb every 1" of movement up through the yokes translates into approx' a 1 degree in reduction in rake i.e you steepen the rake. This has the effect of reducing trail. What this means is that the bike will steer quicker. Go too far and you introduce instability on bumpy roads and particularly on bumpy roads under hard acceleration where the bike can break into a tankslapper.

Another side effect is reduced suspension travel on bikes with conventional right-way-up (RWU) forks. This is not an issue on Ducatis as they have upside down forks.

Yet another side effect is potentially reduced ground clearance - particularly at the fairing chin piece which may touch down under hard braking.

As with everything - it's a compromise. The best way to quicken steering (if that is what you are looking for) is to raise the rear ride height instead. You can do this with something like an Ohlins shock.

twpd is right about the effects of dropping the forks - an interesting read about why it speeds up the steering though, I knew that dropping the forks or raising the rear quickened the steering but I never really worked out why. I was just one of those that just thought "because it does" ;)

Anyway, on a T8, having 10-12mm of the forks showing above the yokes is pretty much an accepted setting to speed the steering. Luckily, T8's have been around for long enough for other people to have worked out some pretty good compromise settings during their racing heyday.

As twpd says, raising the rear is another way to go. Luckily on a T8 you can do that by raising the rear suspension hoop rather than getting a new shock. You can either unwind the rose joints so that there is a longer thread exposed before you wind the locknuts up, but that will only work if you want a little bit more ride height. It's not such a good idea to go too far with this method otherwise there won't be enough of the rose joint thread actually screwed into the hoop to be strong and solid, so the best way is to get a spacer. These appear quite a lot on eBay, and what they do is screw into the hoop in place of the rose joint, then the rose joint screws into the spacer. This lifts the rear of the bike by 20mm, which again is a good setting discovered by those that knew about these things at the time