For The OP:
https://www.bikeforums.net/showthread.php/734796-Someone-stole-the-fork-seat-and-saddle-off-my-bike-(-what-do-I-do

this is the answer to your problem

Folder Fanatic: I, too, am a LA native (working north-ish, in no particular order: Long Beach, Compton, Bell, Echo Park, Midtown, West L.A., Mandeville Cyn, Van Nuys, Canoga Park, Box Canyon, Topanga, Malibu, + some time in the San Gabriel Valley.)

In three separate posts you've suggested that by recommending a locking option I might be out of touch with poorer riders who can't afford (like me?) to simply replace a bike if stolen. That's quite an assumption, not to mention a judgement.

I had a bike stolen from a garage that was broken into. The "object" of the theft was not the bike, but there it was for the taking. That's when I bought my first lock.

I've spent many years on college campuses. Few locked bikes are stolen in daylight hours, though opportunity thefts like a seat or pack occur. To the OP, if it turns out that you have an afternoon class in a crowded room on the 6th floor with narrow halls and small elevators, you may want to think about a good lock. If you can't secure the seat, take it along

My 2 cts.

But not East Los Angeles (California State University, Los Angeles) or Hollywood/Central City (Los Angeles City College/Trade-Technical College). That is the general locations of a few of the higher education campuses I attended-and have lived in or presently live today. I do admit I did not bring a bike on campus as bikes were not used very often then-about 30 or so years ago-as they are now (young female professionals had to maintain a certain image in class at that time-I don't think my professors would like to see me ride around on a bike then, even if modern folding bikes were available!). But once I was free of their critical judgement and evaluations (graduated), I did as I pleased-moving on and going in a really good direction in my life. Inheriting my parent’s house meant that I have to deal with the same stifling gang-bang environment I abandoned when I graduated from college.. So.....in my classical way of dealing a rather bad hand (poor economy & a house I never liked in the first place), I chose to adapt. One of the tools (I have many options and tools) I use to adapt is the folding bike. The basic reason is still the same as the day I first picked up my Dahon Boardwalk-not waiting around for others to offer a safe option to keep the bike safe, but “hide”/bag (not lock) the bike in case I have to go to the hospital in the middle of the night. I don’t really use my present bikes (1 primary & 1 back up) that much. I like them and all, and the trike I will be ordering very soon will expand the potential uses (hauling large amount of groceries) I have for them, but in the end, I don’t care to be set up as crime victim and these type of bikes give me the needed protection from being another crime statistic. Providing I don’t treat them just like a bike (there is always a catch) and resort to locking them up outdoors. And when I want to sell the bike, I can and have done for the first time ever.

It is a free country (last I heard) and others have the freedom to choose what they wish to do-as I hope you will, Martin. This is what I want to do-]I wish to continue to keep my possessions close and don’t listen to some half baked minimum wage part time “employee” telling me what to do with my bikes in the store or whatever. That is the real underlying secret reason of using folding bikes-at least for me. I like the freedom not to lock up and yet not have my bike get in the way of everyone like my former Piccolo (photos below) is doing.

Yes, to CSULA (then called LA State) + East LA CC. But this isn't about our childhoods or who has the most "my-neighborhood-is-more-bad" cred.

As a recent convert to Folderism, and already a member of the choir, I wanted to remind the OP that although fanatics are often correct, their standards might be a bit high for mere mortals who have to factor in everyday risks and benefits.

So I have no quarrel about 1 and 2 of the following advice, but I'd add the other steps with the caveat that everyone will have different metrics for assessing tolerable risks, the environment, and their capacity to tolerate loss.

1, Keep the bike "in touch."
2. Keep the bike "in sight."
3. Lock the bike if in sight but at a distance.
4. Lock the bike if out of sight, even for a short time.
5. Lock the bike if out of sight for a longer time. Here, my research indicates that some popular locks and chains take about 4 minutes to break through, and that is only with a loud, spark-throwing grinder. These chains/locks come with insurance coverage (for the bike) if the chain fails. I limit my lock and chain use to locations with lots of people around- - -where the theft would be so conspicuous that most thieves would prefer to look for an easier, quicker target. (IMO, most college campuses qualify here.) All bets are off if locking in a dark alley overnight.
6. Leave the bike at home. This is clearly the worst choice.)

Or this

https://www.youtube.com/watch?v=xi6XtthI2F0

https://www.youtube.com/watch?v=fa_C9...eature=related

https://www.youtube.com/watch?v=oCu6O...feature=fvwrel

History Lesson Clarification:

Jan. 1964
L.A. State College is officially renamed California State College at Los Angeles (CSCLA) and becomes part of the California State College (CSC) system formed in 1960. -https://www.calstatela.edu/univ/ppa/media/cslainf1.php

I attended & graduated from CSULA far later than 1964. I never attended East Los Angeles Community College. I don't care much for schools operated by the Los Angeles' local government, so I transfered to another far better non Los Angeles operated community college a year after I attended LACC (a real dumpster of a academic education which I had to fix later on) in Hollywood. Los Angeles Trade Technical College is one of the local colleges I sometimes periodically attend to upgrade my sewing skills as I work professionally in that trade now. For trade education, it is wonderful. Everything else, not so much.

As for neighborhood location, I prefer not to advertise exactly where I live for security reasons. Suffice to say, it is in the process of gentrification.

Now To Bicycles:

Any bicycle can be a real pain if I did not take my dad's advice. When he had to remove the damaged U-Lock from my last bike I ever had to lock, he told me, "This is not working, find another bike!" And I did. With his help, I chose the Dahon Boardwalk. When my father was transported to a hospital 5 miles from home in the middle of the night, only the Dahon was able to get me there safely. And because I was able to fold it up, bag it, and then bike was taken in the ICU to check on my father without concern about what to do with the bike. My father did not return home after that, but I was able to be with him before he died-without the loss of my sole transportation as he himself wanted.

The several years I had with now 4 folding bikes (and soon a tricycle), has given me a unique take on bikes. They are here to serve me (not the other way around). If I need one, I use it-if I don't, it stays bagged & stored away until I do. I don't need to use one all the time as I like to use other forms of transit periodically. But that does not mean I forget about them. I sew for the home and professionally, so I expand my designs and create one-of-a-kind creations for the bikes just like I do for the dogs and cats I own.

I think that this is what people on the streets stop me to ask about my bikes over the years. They can see for themselves how fulfilling folding bikes are in adapting to the environment I-and they-function in. And they want one for themselves. Hence, the development of my Website series.

Folding/separating bikes were the choice of wartime. Now they are a choice for an infrastructure environment that does not support anything that does not "claim" it's part of the road (the private 4 wheeled huge motor vehicle).

Now For New Designs & Approaches To Doing Or Participating In:

Sometimes a client brings me a commercial pattern for the home sewing market because they just love it. I don't follow the rules too closely with these patterns as sometimes they are not the best way to construct or even use the garment. I am about to modify this one listed below in order to speed construction plus mainly keep prices to charge for the dress' construction as low as possible. My bag patterns also reflect this philosophy of creating the best and quickest made folding bike bag ever! I don't follow someone else's drumbeat.

https://mccallpattern.mccall.com/m6351-products-14406.php?page_id=96