Weight was in the back of my mind from the very start of the project as I needed a decent handling off-road bike for the trails around here in the Marches. I am no off-road guru able to manhandle 200kg over trails and I needed something less than 140kg and easy to pick up when I would inevitably drop the thing in a Mid Wales bog.
I have a Facebook group that goes into a bit more detail re weight (called BMW Laverda G/S) but the basics are a lightweight custom frame, Valeo starter, Alliant YP18 battery, reduced electrical system and gauges etc etc. I went a bit overboard with the wheel spec and in hindsight could have made a further 2Kg saving very easily but sub 140 was the goal and it's a joy bimbling about on the trails.