OK, but now also my geometry is correct!
However I need hard spring.
Ok, tyres (28) are probably too soft for my track with 22 °C, so very hard spring were necessary. En fact with a new set of 32 they are too hard, the rear was unstable. So maybe something like 20 lb should be the way to go with this tyres, or better, I'have to use 36 tyres with more standard spring, a bit too hard rear than front.