My take on this.

European brands tend to stretch the OCI more to do with environmental concerns than actually protecting your engine. Triumph, BMW, KTM and the likes have OCI all over 10k.

There is certainly no harm in shorter OCI, other than said environment concerns and damage to your wallet.

However in all likelyhood, the truth is probably somewhere in between.

OCI depends a lot on the following items
1) total oil capacity ( more oil, longer OCI)
2) how it is ridden. Short trip, city , high temp, hard riding, then shorter interval


Oil itself does not degrade. What does is the additive package in the oil and how contaminated it is. So even if your additive package wears out, your oil still works as lubricant.

My 800nk's factory OCI is 15k, with 2.8L full synt, While the dealer ask me to do the oil change every 3k. I'm doing 10k at the moment and after opening up the engine for VC (32k in 1 year), everything seems ok on the parts that are visible.

So take either ends of the recommend OCI with a grain of salt.

it should say in your owners handbook.

Typically it is the mileage or 1 year