What CaliZed9 said is accurate.
The 60 SAE rating comes into effect at 100 degrees Celcius and will be too thick
for normal temperature riding where I live.
The flow cst rate for 10W40 oil at 100 degrees is 14.
The flow rate for 10W60 is 24 or way to high for our engines.
I stupidly assumed that the high viscosity would only kick in at very
high operating temperatures, like track days and would be advantageous,
not at 100.
I never liked when doing a warm engine oil change, that the viscosity seemed
like water with 10W40.
They changed the label on the Motul 7100 10W40 saying that it was for off-road
I always seem to create problems for my poor Zed.