There seems to be two variants for the trident, in terms of oil level. "For vin# bikes - from 4901*! - oil grade 10sae at a level of 94mm max. For Vin# 4902* sae of 10 wt again but 109mm but because '*' means cannot be filled over -97mm.
And '*!' means where motorcycles that have been modified to a later fork condition, the post vin4902 figures must be applied. Kits to modify cycles to the post vin 9083 condition are not available - that's from the Triumph manual! I imagine your's being a 92 (and un-modified), an early one - so 94mm with the fork compressed is going to be the level/air gap. You can make a gauge from a biro case, a plastic circle with a hole in it, some tubing and a turkey baster. Drill a 2mm hole about 1.5cm from the bottom of the biro casing - which you should seal. Measure from the hole to the plastic circle: which you put the biro case thru' the middle off ....tube - etc... and squeeze the bulb! Hagon 'progressives' with 15wt and maybe a bigger spacer tube would firm up the dive! That's with a stock pull thru' of 25mm.
