The International CBX Owners Association

Personally, i wouldn't ride on a 15 year old tire.
For stock wheels i would use a 100/90-19 Bridgestone BT45. Plenty of threads on tire choices.
Had good luck recently with ordering from FortNine.
https://fortnine.ca/en/

I deflate the bigger tires to clear the bolts then, reinflate.

I don't mount tires with build dates over a year old. Others may offer different opinions but, I'll always err on the side of caution.

Hard rubber isn't safe.

+2 on that.

Don't compromise on tires, brakes and suspension.

Agreed on the tire age, 15 is way beyond my comfort level. I purchase most items from Fortnine already, was looking at the Shinko 230 Tourmasters.
Great price, V rated, might give them a try.
Brakes calipers have new pistons, new seals, new front and rear master cylinder kit.
Front rotors are perfect, rear rotor needs to be turned down, it has a bit of scoring.
Just installed all new bearings on front and rear wheels.
Heard that the rear air assist suspension is not great as stock, heard good things about IKON replacement. Any others worth looking at.
The front fork springs are stock, what is a good alternative. Saw some Progressive springs, I think IKON too.
I'm in Ontario, Canada, so US supplied stuff is pretty dear, let alone shipping. Damn us Canucks.

For the rear suspension seems like Progressives 465-1115B are ones of the preferred replacements. I am thinking of doing mine over the winter.

For the front, Progressives are popular too but one of the preferred upgrades are Race Tech springs with the Gold Valve emulator Cartdridges.

Luc et al, Those are the two best upgrades that can be done to a pro-link. Well worth the $$$. Anything else is a marginal return on investment. Those two are gold. (The progressive is a good one. Nothing wrong with the Ikon.)

Try letting the air out of the tire to mount , once complete air tire to recommended pressure.

1. Deflate the tire before installation.

2. And/or replace the hex head bolts with allen, button heads.

3. Or, put the fender on last using a flex head, 10mm ratcheting end wrench.

I've done all three.

If you have a CBX, you'll find yourself buying tools that aren't in the usual tool box.