[adouglas]

Wow, it looks like everyone's out of stock on tires.

Didn't you say in the TTD group that your tires are only a few years old with low mileage? They ought to be okay if so. First-time pace is more like a spirited road ride than anything else.

Tires that are really old and hard are what you want to avoid. A tire more than 5 years old may still be okay, or maybe not (look for the date code on the tire to see how old it is... the code is a four-digit number, usually stamped in an oval outline. The first two digits are the week of manufacture, and the second two are the year, e.g. 2419 means the 24th week of 2019).

A tire that's gotten rock-hard from exposure to UV light and ozone won't serve you well. A tire that's excessively worn or squared off is done no matter how fresh it is. A cracked tire should be replaced immediately.

Re scooter tires... it's just a label. The thing to pay attention to is the speed rating of the tire. Scooter tires are typically S-rated, which means they're not designed for prolonged high speed use. Do some Googling on "tire speed rating" for more info.

If you really must get new rubber, Shinkos won't blow up or anything like that. It's just that other brands make better tires. I've never used Shinkos myself but I've never heard anything particularly good about them.

The pregen Ninjette is a nifty little bike but tire availability really is the limiting factor. The industry went to 17-inch wheels a long time ago.