nooby chain tension question

[kokis]

Hello guys.
One guy told me that my chain has to be tighter. And he did it tighter. It is ok for one rider and ok for two if second one is light weight. But if second rider(passenger) is bigger I feel like chain scrubbing something. But I don't see what it scrubs. Also I have 14T mod.
Now chain is close to owners manual recommendations which I always considered wrong and over-tight. Is it very bad to have chain tension at highest allowed tension?(I mean it is still ok but little bit too much tension when 2 people on board) Also I ride a lot of bumpy roads and suspension always works like crazy.

[Slide Panda]

It's better over loose (to a degree) than over tight. Loose, will cause slop and lash which is anoying - but if it's too tight it puts strain on your main bearings and can accelerate wear or even cause a failure. of course if it's too loose that can lead to skipping teeth.

The chain is less likely to rub on anything with the bike loaded vs unloaded. Unloaded the chain is usually resting on the upper guard- possibly deflecting a bit at the swingarm pivot.. As you load the suspension you're working to a point where an unimpeded line can be drawn directly from the top of the front sprocket to the top of the rear, and the top of the chain is what'll be tight when you're on the power.

How much weight is on the bike when you're 2-up?

[kokis]

~308LBS
I will lose it a bit. It is too annoying and not pleasant.

[Slide Panda]

Not sure about the newer models - but the older ones were sprung for around 160 pound load. With over 308 pounds you're probably bottoming out the suspension or close to it over any bump of note