Berlingo whole + Mrs + 2 kids, so I used the previous short set to manoeuvre the bike to the car and had not yet had the refurbished stanchions on the bike).
When my normally calm, lateral thinking engineer's brain went into melt-down, I cried out for the help of See See Thor, and then XS650 race veteran Travis (photo above). But they were as foxed as me, why the fork caps would not screw down - it's normal to to have to exert considerable pressure to engage the thread, to stop the caps becoming dangerous projectiles, but these bastids were being ridiculously stubborn.
I had replaced the rusty pipe sections that had previously been used to fill out the space above the springs, with new PVC pipe of the same length (151mm). Apart from a set of new Hagon progressive fork springs (same length as the old shot ones), nothing else had changed....
Then, a guardian angle in the shape of a hairy biker, Rod, racing his even more hairy, rusty springer Triumph also in the chopper class, came to my salvation.
He noticed that the spring top was slightly mushroomed where it had been cut and flattened in its manufacture. The new springs were getting caught inside the stanchions at the top, so not dropping down as low as they should.
The old fork tops - the 3-position pre-load adjusters, were properly shagged. But not all parts for the XS are readily available. After a bit of cross-referencing I figured YZ250 caps which also have a 28mm fine-pitch thread might just marry. These repro beauties are from the very friendly and efficient Yambits in North Yorkshire.