I bought some of that synthetic 140 wt from Graingers, but it's pretty runny stuff. It was all on the garage floor in a week. 90 wt hypoid gear oil seems a lot more viscous. I made a mix of 50 wt engine oil and STP for the 850's swingarm. It took several weeks to leak out.
kommando, where did you hear about the 100C temperature thing? I've been using Redline GL-4 rated oil in the gearbox mainly because of the GL-5 controversy, but it's hard to find locally. If GL-5 is really ok, I'd rather switch to it as it is much easier to obtain.
Its from an engineers design handbook on the GGB bearings website, its in the section on SY bushes which are high lead bronze bushes. I can never remember where I put the link butv I have posted it twice before. I've had my bike since 82, its never had anything but plain EP90 except for last 2 years where I now put fully synthetic in, other than the layshaft bearing going its never had any bearing/bush needing replacing in the gearbox.