Instructables

Bike seat chain lock (that doesn't look stupid)

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Picture of Bike seat chain lock (that doesn't look stupid)
I've seen lots of bike seat locks made from bike chains that look stupid - they're giant loops of bike chain haphazardly looped around the seat rail and the bike frame that flap in the wind.  Effective, sure, but they look like crap. Who wants that?

My bike seat [bike] chain lock really isn't anything wildly different, but I think it looks quite a bit better by using a little less chain and shrouding the chain in a piece of innertube.
 
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Step 1: Materials, tools

Picture of Materials, tools
Clearly the most critical part of the equation is a bike chain:

Go to your local bike shop and nicely ask for an old chain that they've discarded.  The nice bike mechanic should oblige you with some old chain - 2 feet should be more than enough.  If they say you'll have to buy one, I'd go to another shop - bike shops usually have these things in the garbage can so I wouldn't pay for one (although bike mechanics always like tips - throw em a few bucks and the next time you get your bike serviced there, there's a good chance you'll get A+ service).

Greasy chains are good.  Although they're messier to install, the grease ensures that the chain won't rust and deposit rust marks where the chain is looped around your frame.

You'll also need a chain break and around a foot of innertube.  I use some 700c by 18-23.  Certainly you can use any size that you want, but like I said earlier: loose = stupid looking; you don't want anything flapping in the wind.

Step 2: Pin in last link of chain

Picture of Pin in last link of chain
It'll make your life MUCH easier if the pin is in the last link of the chain, as pictured.

If the bike mechanic gives you some chain and it doesn't look as pictured, don't fret.  Use your chain break and take a link of chain off, but don't push the pin all the way through.

If this doesn't make sense, you've probably never used a chain break; after you use it once, perhaps twice, it'll be pretty obvious.
jujubeetuna15 months ago
turned out pretty good. I recommend leaving a little extra chain. I put some inner tube to protect the paint as well. use about 6-8 inches and slice the long piece of tubing about 3/4 inch on both sides and tuck the other tubing into it. I also used a few zip ties to hold the rubber tubing in place better.
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tonyscott8 months ago

Good idea, thanks for sharing.

rmayers11 months ago
Thank you for this!

Though I think the 'Klein Bottle' addition would be very useful too...
macrumpton1 year ago
When I lived in NYC the first thing you did when you got a nice new bike was burn a hole in the seat with a cigarette in a conspicuous place, to make it worthless to steal. Then you either spraypaint or cover your beautiful frame with tape or inner tube rubber to conceal its value. Then you get rid of all the quick release levers and replace them with bolts. Finally you get a chain that could hold King Kong down. Even so you were best off taking your bike indoors, as even the crappiest looking bike eventually got stolen (as all of mine did).
modern man1 year ago
Interesting idea! You could also slip a couple pieces of tubing (like heat shrink or a straw) over the chain before you rejoined it. Keep them long enough so the ends would be covered by the inner tube. Save your frame and any rattling of metal on metal.
Cheers
ak088201 year ago
1. There are bike saddles that cost upwards of $100 - e.g. , Brooks, that makes it theft worthy.
2. The thieves easily undo allen bolts and regular bolts holding the saddle to the seat post and the seat post in the frame.
3. The chain ties the saddle to the frame via the rails, making the theft more cumbersome if not impossible.
eheath11 year ago
Would it not be easier and more effective to secure the seat with a good old fashioned Allen bolt rather than I quick release? The chain could easily be snapped with two hands. And before you argue that a theif could easily be carrying an Allen key, well I'd be more worried about the several more expensive items on my bike held on with Allen bolts
Ryan271828 (author)  eheath11 year ago
The tensile strength of a properly assembled bike chain is probably around 20,000 psi, I'd like to meet the chap who could snap that! Good point though!
It wouldn't be tensile strength that you would worry about, bike chains are made to bend only in one plane, bending one sideways, if there is enough slack, it could be broken easily. If secured with little slack, it would be hard to break.
If you're worried about the strength. Use a motorcycle bike chain...
wingerr1 year ago
All this talk about Klein Bottles, and I kept thinking it was some kind of water bottle made by Klein bicycles until I looked it up. Interesting stuff!

That'd be a good way to terminate the ends on both sides to prevent the clacking noises while riding.
apu20101 year ago
use less expensive seat or open and carry the seat with you if possible, or use old fashioned nut and bolt instead of quick release, i bet all thieves don't carry a wrench in their pockets. if the seat has to get stolen it will get stolen no matter how much you try hard, so please be positive and not worry about your bike seat whenever you park it.... goodluck
Unfortunately thinking positive probably has little effect on the behavior of vandals. Along with the nuts and bolts approach, I'd put a screeching motion detecting alarm in the seat that would go off with any disturbance; that might send them packing or at least get some eyewitnesses. An RF remote controlled alarm packed under the seat and protected by a metal casing might be and easy way to go about it.
stumpster1 year ago
I've been doing this for years, I guess from when I started riding in NYC. The only thing I do differently is to buy the woven cable covers from an auto parts store, and usually match the colors of the bike.
wingerr1 year ago
Is the seat post pictured one that secures with an internal expanding bolt, like handlebar stems? I don't see the QR lever usually used for seat height adjustment.
I've seen several bikes parked in the nearby neighborhood where some miscreants stole the seats off from them, and they generally seemed to have quick release mechanisms to make it easy for them. I'm not trusting enough to park my bikes on the street, but if I did, I'd get rid of all the quick release levers and go with old nuts and bolts. And sit in wait around the corner with a baseball bat. It'd probably be community service to set up some tamper fodder to see what kind of low life bums get snared.
r_bailey1 year ago
[4:15:37 PM] R. Bailey: Really? Really??!!!!! We've reached the stage of such pettiness that is necessary to chain ones bicycle seat to the bike to keep it from getting stolen? I thought it was bad enough when I had to run a chain through the front,& rear tires AND the bake frame to insure I had a ride-able bike when I came back. Now if they can't steal the bike they steal the seat out of spite or something?
Pretty much.
tinpusher1 year ago
First let me say, nice 'ible. However, I do have a serious question. What is the point of this? I know that sounds harsh but I really don't mean for it to. What I mean is this. Doesn't it negate the "quick release" ability of your seat? And, if so, why not just do away with the quick release and, by so doing, do away with the additional weight created by your chain lock?
mlbenson1 year ago
Would heat shrink tube work....like electricians use? It would get really tight.
Guess I'm stupid.
I must be.
Anyway here is my question : how that chain will loop around a strong point in order to secure your bike ?
Also, it seems the weak point will be the padlock. If the padlock has to go into those chain holes it will be a rather small ones that could be easily broken by experienced hands from the thief trade … 
Ryan271828 (author)  vincent75201 year ago
I can see your confusion! This device mitigates theft of the bike seat only. In some places an expensive seat can get stolen off the bike - this device locks the bicycle seat to the bicycle itself.

This isn't involved in securing a bicycle to something else (like a bike rack). It doesn't involve or use a padlock, or at least it's not designed to.
Ah !
This explains !

Maybe I'm not that stupid after all ! lol

Thanks for your reply.
Modarius1 year ago
I'd be interested in seeing at least a picture of how you did the "klein bottle" inner tube wrap but thats just me.
wobbler1 year ago
Good idea. I'd run it up the seat stem with a couple of cable ties though. Or is it better to leave it separate as a visual warning?
Ryan271828 (author)  wobbler1 year ago
Good thinking!
loony11 year ago
Dude, great idea! I have an alternate method. I'll share if you like...much less weight. Tom
ehsiung1 year ago
Great idea, very clever way to re-use old bike parts.