If you like repairing bikes, then these happy ending breakdowns are part of the fun. Glad it worked out.

Can't the derailleur have a guard mounted, like a chain guard, to keep sticks from poking it?

Sort of. Some bikes have them but it would add weight and for derailleurs with a lot of travel the guard would have to be huge or move with the derailleur and would be subject to catching the sticks itself. It's an imperfect world.
Could lead to a situation like this: (starts at 10:02)
https://omny.fm/shows/selected-shorts/love-prohibition

Needs an automatic transmission. :yesnod:

Internal with belt drive

Wow. At first I thought these were automatic transmission. I wonder how far off that is?


Can old bikes be retrofitted with this?

I think so, but I haven't looked into it. I saw one in the wild in British Columbia, the owner was pretty chuffed. I wonder about the lifespan.

So today I popped out the snap ring that holds the plunger for my brakes. Hopefully it holds now that it's back in. Again a zip tie allowed me to ride out by putting the plunger in and holding the brake lever.

Didn't have any chewing gum, eh. ;)
I got an email tonight from a guy who blacked out driving in Philly and killed a couple people so they yanked his licence probably permanently.
He said he was buying a Zugo Rhino electric bike.

He lives in Cherry Hill, NJ and claims the law enforcement over there has declared if it doesn't exceed 20 mph no licence or registration needed.
That also means no insurance. If you hit a person at 20 mph you could kill them, worse cripple them for life.
If you hit a vehicle or other property at that speed you could cause tens of thousands of dollars damage.

Here's a couple of starter bikes...

Carbon fiber is cheaper than wood?

At least it'll come back to ya if ya wreck fast enough.

Ok, Boomer(ang).

I think the word we're looking for is "bulletproof". This guy has put many, many, many miles in the saddle and this vid gives good info.

As for retrofitting an existing bike, yeah, but bring money.