Tonight I locked my Downtube VIIIH outside of a friend's house for a couple hours and when I went to leave, lo and behold, my seatpost was missing. The bike was locked with a 1.5' cable and master lock (which doubles as an easy seatpost height marker) which I usually also lock the seat with, but this time there wasn't enough slack.

I'm thinking I'll either do:
A) Get a new seatpost and sell the bike along with all spare parts (namely, two big apple tires, a new 39 T chainwheel, and a new rustproof chain). The Downtube will never be safe outside without extensive locking and is simply too large and ungainly to impose upon hosts; The Carryme is plenty of bike for urban riding.
or
B) Get a new seatpost and a 3-6 foot long steel cable and religiously secure seatpost, wheels, and frame together when locking up.

That's terrible! I swear, people would steal breath!

Me, I'd go for the longer cable and another seatpost. A lot cheaper than getting another bike. (You might ask Dynocoaster. He swapped out his stock 8HN seatpost and saddle.)

Thanks for the tip (although I think the seatposts on the latest downtubes may be a different size). To tell you the truth I was thinking about selling the bike anyway because it just isn't meeting my needs, but it kills me to just put all the spare parts to waste (and now the thought of sinking even more money in a new seatpost makes it even worse).

What did Yan say about the seatpost diameter change?

#3 Wider seat tube on front and no suspension models ( 30.4mm from 27.2mm )

Could you just replace the seatpost QR with a pinch bolt?

Sounds like the "greatest city in america" isn't too kind to cyclists!
Good luck with your decision.

Hmm, looks like the seapost from my Carryme is a perfect fit (and lighter too).

I always found the Carryme seat more comfortable anyway, plus I didn't need all that extra length on the stock post, so I think I'm going to just move the Carryme seat and post over to the Downtube and take this as an opportunity to upgrade the seatpost and seat on my Carryme to something lighter.

Does anyone have any recommendations on lightweight seatposts without getting ripped off? I'm thinking maybe a carbon seatpost with a Tioga Spider saddle. Now I just have to go practice saying "I'm sorry honey, but I had to buy a new seat and post because my old one was stolen!"

I can relate, having had 3 posts go in the last 3 years; One was a very-hard to replace Peugeot size and I was not a happy bunny about that!!!

Something a guy I used to know with a Dahon did was drill a small hole in the last 1/2 inch or so of the tube then when the tube was down and protruding through the bottom of the frame, he could just attach a wee little padlock (a combination luggage one I believe) that kept the post in the frame and would dissuade most casual thieves. A bit easier to carry than extra cables etc as you can keep it on your key-fob.

I guess you could take the seatpost/saddle inside with you.

I'm not going to carry any extra cables. I usually lock my bike with a single cable wrapped around the rear triangle which I wrap around fixtures and lock back on itself with a padlock. By leaving it wrapped around the rear triangle the cable serves a dual purpose because when I lock the other end of the cable to the saddle rails and pull it taught I know the seatpost is at the right height.

I intend to just replace this cable with a longer cable so I can string it through the saddle rails and wheels too. I'm hoping that double length will be long enough to do the job if I fold the bike before locking so that I can use the same method for checking the seatpost height.

I'm not willing to use multiple locks, which is why I'm wondering if perhaps I'd be better off just selling the bike now before the cable gets snipped and the whole thing gets stolen.

A bit late now I admit, but one of the many advantages of a folding bike is that you can generally fold it up and take it with you into a building. Taking off any easily removed parts such as seatpost, lights, computer and pedals (if MKS Q/D pedals) is the next best option.
Otherwise perhaps, fold it up before locking it to something solid with the best lock you can afford.

Had a commuter bike get stolen when just locked with a (rather stout) cable. This was in a high-theft area, though. Thing is, in another part of town not a couple months previous, a homeless guy came up and complimented me on my bike, saw I was using a cable and told me those things were no good, thieves in the area could cut through them "like buttah." (this was Boston...)

One idea: take an old chain and attach it through the frame and the seat rails. That works on a full-sized bike, don't know about the Downtube.

The thing is, generally, you can't with most folding bikes. That's why I've been locking my Downtube outside and why I'd like to sell it.

The Brompton, the Strida, the A-bike, and the Carryme are really the only folding bikes you can generally take with you everywhere, and even at that the Brompton and the Strida are pushing it.

I think the next best option is taking the subway or maybe even driving. Taking the whole bike apart just to go inside for an hour or two is the last thing I want to do.

And how will the best lock I can afford do? No matter how it's locked with some basic tools any amateur bike mechanic should be able to strip a locked up bike of everything except the wheels and whatever part of the frame is contiguous to the rear triangle (basically everything that isn't a loop or welded to a loop).

This is true, and if your folder were equipped with all Dura-Ace components, I would be worried. But I don't think the person who stole your seat did so because he wanted to resell it (I don't think that there is much of a market for used seats); I think he did so because he saw that he could. In other words, you were more the victim of vandalism than theft.

that's why I like my gekko, I can take the security pin with me,
the bike will collapse on itself when the thief sits on the saddle.
I know, I forgot to put the pin in when I tried riding it out in my hallway,
it just folded up. for short trips to grab some take-out it's perfect.
like you, I'm not going to buy a giant lock, the lock will cost more than
the bike's worth, I'll rig up some zip tie to secure the QR seatpost.
Lot's of NYC office buildings are still bicycle unfriendly. that's if you
want to work in the corporate world.

Get tough - Just ride it without a seat.

One guy does it around here all the time.

The NYC Kryptonite lock is guaranteed against theft (https://www.kryptonitelock.com/Produc...=1000&pid=1095).

makeinu, I just want to tell you how sorry I am to read about your seatpost theft. How awful! Everytime I think of getting up the nerve to lock my bike outside, I read a story like this and it sends me running away screaming.

Good luck getting the seatpost and saddle replaced!

But you need to have the broken lock in order to make a claim. What if the thief takes the lock?

God only knows.

+1. Why else have a folding bike? You are lucky you didn't lose the whole bike. The only 95% safe lock is the NY Kryptonite, and only then because you are 95% likely to get the money back from their insurance policy once the bike is stolen.

I was denied entry into a building recently (they had a metal detector and wouldn't let me place the bike on the luggage scanner). I was supposed to give a presentation that was important for my work. When they wouldn't let me in, I just called them and apologized that I wouldn't be showing up for the presentation.

Could a lock be built into the quick release?

Sorry to hear about your stolen seatpost that sucks....had that happen in university...

One of the things I love about my Tikit is that I don't have to carry a lock with me, I just fold it and bring it in with me. So far I haven't had an issue with that strategy.