I’ve seen it about four times in the last couple weeks. Regular looking riders with a regular looking plastic bag on their regular looking bicycle seat. Not raining or anything.
What’s up with that?
Peace,
mangeorge
Crappy or worn bicycle seats will get soaked when it’s raining.
At least that’s my conclusion. Any decent seat can just be wiped off.
That’s pretty much it. Although, in my situation, I have a good seat, but I rarely carry anything I can wipe it down with and slapping the rainwater off with my palm is fairly ineffective.
Or they’ve got a decent gel seat, like mine, which has a fabric, stretchy and highly rain attracting cover.
I replaced the cheap, hard, wipe-able seat because it hurt.
Neither snow nor rain nor fog stayed these cyclists from the ardous completion of their chosen journeys.
NOT raining.
Has it rained any time in the past several days? My bike seat is a porous cover over rubber foam, and takes at least that long to dry out.
Alternately, they’ve just gotten into the habit of keeping the bag on all the time, just in case it does rain.
Yeah.
So when cyclists leave their cycles unattended, together, do you really know what happens? I mean, do you want to return to pick up your cycle to head off and find all the new tricycles all around them?
Not raining now doesn’t mean it can’t rain later. When I biked a good bit (in college, so a while ago), I’d leave a bag over my seat because I didn’t want to get caught unawares. It’s just a habit you get into after a while - dismount, cover your seat.
Absolutely.
I only got caught once and that was enough. I also like the suggestion of preventing unwanted bicyclettes.
A plastic bag also covers ragged and torn bike seats, so they last a bit longer. They are cheap so no-one will steal them, while they might steal a neater cover.
A brightly colored cover makes your bike easier to spot and retrieve in a throng of bikes.
Pshaw, everyone knows that the larval form of bicycles is paperclips.
Does Scotchguard not work on neoprene? Why need an incredibly dorky plastic bag?
It’s actually very easy. You leave it on when its dry and take it of when it has been raining (put it back on again when you reach your destination. Also, about the gel seats, if some joker decides it is funny to make a cut or a small hole in the seat, you’ll be riding a sponge…
Dork chic. Usually observed in those who dismount their bikes instead of just get off. Like Charlie’s brother Alan. 
(That’s “get off” in the non-orgasmic sense)
Scotchguard would probably wear off quickly from a bicycle seat due to the wear and it won’t keep your seat complete dry in a drenching rain. A plastic bag is cheap, effective, and simple to replace.