Modern Vespa

I was cleaning out stuff from my BV350 top box and saw a notice (which I hadn't seen before) saying that the front tire pressure should be increased to
~35 psi. I can't quite figure out why. My GTS had handlebar weights that came with the top box; I get that, but not this.
Any ideas?

but I did want to bump this back to the top so that people with knowledge could speak to this.

I don't know the BV 350 but it seems that the recommended pressure is a bit high.

Thanks... it's not a burning issue; I was just curious about why that'd be important. I keep my tires on the hard side anyway.

If the top-box was fully laden, the extra weight that high up would throw quite a bit of extra force onto the front wheel during braking (which is the front wheel's main stress). So I can quite imagine they might state a higher pressure for a top-box - though I've not seen that for other bikes. Do they also recommend a higher pressure in the front (as well as the back) when carrying a passenger?

That's probably the most logical explanation for their reasoning; still it'd have to be A LOT of weight! Probably some engineer overthinking a perceived problem.
As for riding two up, I think almost every bike I've owned wants to have increased tire pressure. I keep it there as a matter of course.

I like the explanation jimc offered, but it doesn't make sense when you consider the two-up front tire pressure. The front tire pressure doesn't change for two-up. It remains ~32 psi.

However, the top case has a little sticker that says the front tire pressure should be 36.26 psi with the top case attached.

I would really like to get this resolved. Correct tire pressure is critical for two wheelers. Does anyone know the correct pressures for safe riding?

good luck on getting that .26 to read on a normal tire gauge. That must be an uber critical number to define the pressure to that level.

Well, standard measurements have to be picky. It's the only way to make up for how goofy the whole system is. I mean look, metric only requires two significant digits.

I say start with about 15-20% over recommended pressure and reduce the pressure until you get to the point of best comfort/performance/tread wear/noise making sure not to go below the recommended pressure. to me the recommended pressure should be the minimum pressure. also make sure not to go over the max pressure stated on the sidewall of the tire, especially if you are going to be pushing the tire anywhere near its maximum speed or load rating.

as long as you are between the vehicles recommended pressure and below the max tire pressure you are in the safe zone, although tread life/wear, noise, and performance may be affected by the particular pressure you decide upon.

I keep mine at near max recommended pressure anyway, but I've gone 20,000 miles with no issues of handling or tire wear. Have the handle bar weights with the Piaggio Top box.