| Felix the standard offset of my original Yokes I make 36mm which results in the standard trail figures of either 91mm or 97mm depending on which rake setting is used.
As I have a Lengthened swingarm (standard one extended) which Ray Stringer had done when he was racing a much modified 916SP Devimead Ducati along side team mate Steve Hislop on a full Factory Corsa in 1995, I thought I would go with his settings.
From what I can make out Felix your bike on 23.5 degrees with 28mm offset would be runing longer than standard trail of 99mm which is quite a common figure for the Factory race bikes.
So the answer to the question --- Why increase trail by reducing offset ?
Answer--- because its what appears to work on Ducatis
which is one reason I'm against using the standard 23.5 degree setting with standard offset yokes
He fabricated a different different headstock spindle that allowed him to use the standard SP yokes fitted with eccentrics to achieve a yoke offset of 32mm identical to the 1994 Factory Corsas. Hizzys 95 Corsa had a offset of 30mm
Foggy's 955 from 1995 ran 100mm of trail and a head angle of 24.5 degrees along with the longer Corsa swingarm, used 17" wheels and had a weight bias of 51.5% Fr and 48.5% rear weighing 153kgs with No fuel tank but with oil & water. Wheelbase was given as 1428mm.  | 
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