I the whole steerer is 185 mm, I cant post links, this is for other fork from the same website:

Bike Fork 20" Thread black Ø22,2,Shaft 240mm/Thread 130mm

Size • 20"

Shaft
Outer Ø • 1" / 25,4 mm
Inner Ø • 22,2 mm
Steerer • 240 mm
Thread • 130 mm

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if headset is 130mm + 40mm then I would need to cut about 15mm ?