Bob
That's what a Honda dealer suggested for a bike with 150,000 miles. But, you have a good point there as well.
Yeah... That is just like the marketing "Hype" with "High Mileage" oil for cars with XX number of miles..
If you Don't have a problem with the Viscosity oil that is recommended, don't change.. Go lighter if you can.
FEW parts people or mechanics know much about oil although they will try to impress upon you differently.
Ask them a few questions...
What do the numbers and the "W" such as 10W-40 mean ?
Does a Newer API Rating, SL or SM automatically supercede an API Rating of say SG/SH or even SJ ?
Does a GL-5 Automatically supercede a GL-4 ? (Gear Lube)
Is a Synthetic oil such as 10W-40 "thinner" than a petroleum 10W-40 ?
Is a Break-In period required before switching to synthetic ?
Is there a problem with using synthetics in wet clutch applications ?
Will using a Synthetic oil void your warranty ?
You will be surprised at the answers you get from people making "recommendations" and not even knowing the basics.
Don't get me wrong.. There are a few Parts people and Technicians that know, but, they are few and far between.
Bob