Is it safe to hit my bike with a pressure washer foam cannon?

You'll almost certainly be fine, but you did brush past a couple of spots worth being careful with. I've been running a foam cannon off my pressure washer for a few seasons now and here's how I handle it. Wheel bearings are the main thing people worry about, and rightly so. A modern sealed bearing shrugs off rain and road spray all day, but a narrow high-pressure jet pointed straight at the seal can push water past the lip. The saving grace with a foam cannon is that it's low pressure by design. The fan is wide, the psi at the surface is gentle compared to a zero-degree nozzle, and the foam clinging to everything means you weren't actually jetting anything. If you kept the wand a foot or more away, you basicly gave the hubs a heavy rainstorm. I've soaked mine the same way for years with zero bearing issues. Just spin the wheels after and listen for any grinding over the next few rides if you want peace of mind.

The chain is a slightly diferent story. O-rings don't love high pressure directed straight at them either, but again, foam distance saves you. What matters more is what comes after. Dry the chain properly and re-lube once it's dry, because trapped moisture sitting between the o-rings and the plates is what actually causes rust. Do that and a foam bath is no worse than riding through a downpour. Electrics near the headstock, dash, switches. These are designed to get rained on, so a gentle spray won't kill them. The one habit worth building is letting everything dry fully before you hit the starter button, and giving connectors a blast of compressed air or a blower if water pooled anywhere. And avoid sticking a narrow nozzle tip directly into switchgear or under the seat. My general rule now: foam everything, but when I switch to the rinse I back off around the hubs, chain, exhaust tips, and any exposed connector. Foam at distance is harmless. It's the concentrated rinse that gets bikes in trouble.

I only ever use mine on the car so far, was too nervous to point it anywhere near my bike after reading horror stories about fried electrics. Good to hear the gentle spray angle works out. One thing I've noticed on the car is the foam seems to cling way better if I do it in the shade, in the sun it just slides off before it's done anything. Do you guys find the same on bike fairings or does the smaller surface make that less of an issue? Also curious wheather you cover the dash with anything before foaming or just let it drip dry.

Been washing bikes since the days when the only option was a bucket, a sponge, and the garden hose, and let me tell you, half the time I still do it that way. Foam is nice for lifting the grit off before you touch anything, I'll give it that. What I do now is foam it, then go over it with a wash mitt and the two bucket routine before rinsing, because foam alone never gets the bugs and tar off the lower fairing. One thing I'll add, let the bike cool down first. Foam baking onto a hot engine turns into a crusty mess that's harder to shift than the dirt was.

Update: checked the hubs and chain a few days later and everything feels fine, no play in the wheels and the chain isn't showing anything wierd. Ran it again yesterday and tried the shade trick someone mentioned, huge difference, the foam actually stayed on long enought to work. Also went over it with a mitt after rinsing like the older guy suggested. Skipping the dash area from now on regardless.