This is on my Viffer but it has the same hydraulic clutch layout as the storm
I’ve checked the hydraulic over and there’s no sign of a leak

The bite point on the clutch is all over the place some times it’s close in to the bar with the clutch being fully disengaged just a few millimetres after and sometimes the lever is almost fully out before the clutch is fully disengaged. Also when sat at the lights with the clutch in the clutch can start to drag
Now I’m thinking it’s got a warped plate in the clutch I.E different amounts of heat in the plates altering the amount of warp hence the bite point moving about
Just wanting to run it past a few heads before I go opening the engine up and see what you think or if anyone has another idea that may need checking