I use 10W40 Mobile 1 synthetic 4T motorcycle oil.
I've run Motul 10w40 since the first change it it works perfectly. Depending on what oil they put in, it will probably shear down to a 30 weight in about 500-1000 miles anyway.
I use what I find 10w30-10w40-10w50-15w40-10w60 ..... ..... I must say that I have never had any problems, very often trip to two with three suitcases, the important thing is that there is oil and replace at short intervals.
If I find the hair on the egg, I noticed that with the 10w30 after long trips, the gears change has become more tough, while the others are not oils.
ahh Frulk so you trip to two with 3 suitcases and find hair on your eggs too eh? lol