# Earth magnets to prevent saddle theft?



## SFTifoso (Aug 17, 2011)

I'm wondering if anybody has tried putting a small earth magnet in the saddle clamp bolt (allen head) to prevent an opportunistic thief from stealing your saddle. Reason I ask is I want to take my bike work. It has a nice bike parking rack thing, with security guards, but still someone could walk in and in 10 seconds walk away with a $90 saddle + $50 seatpost. Probably unlikely though, I'm more concern one of my "co-workers" walking away with it while I'm still inside!

I've heard about the ball bearing and crazy glue trick, but I don't like the idea of mixing acetone with my bike's paint. And no, I can't be careful, I'm a clumsy impatient oaf. My main concern would be how do I get the earth magnet out of the allen bolt? If I hold another magnet next to it, will it be more attractive to the magnet than the steel bolt?


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## tarwheel2 (Jul 7, 2005)

What is an Earth magnet?

However, if it's just a round magnet, I would think you could remove it from the bolt head by just passing a stronger magnet over it. Wouldn't be hard to test.


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## logbiter (Sep 14, 2005)

the main problem is it probably won't stick to the bolt very well (assuming it's stainless). I just stuck a buckyball in some bolt heads (a good excuse to run out to the bike rack this beautiful morning) and the only one it stuck in well was a non-stainless bolt. A regular little magnet didn't pull it out though.

I haven't looked for alternate bolts, but what about a torx head instead of hex? 
Many years ago I used to use a "seatpost keeper" that was a L shaped piece of steel that inserted (pounded in like a starnut) into seatpost that had a stainless cable attached with a bob hanging down that hung below an extra long bottle cage bolt. It at least kept people from easily yanking out your seatpost as the bob would stop against the bolt.


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## brucew (Jun 3, 2006)

Why all the screwing around? Whatever you can plug the hole with, anyone else can unplug just as easily as you can.

Get a security seatpost bolt. While you're at it, get a set that includes security skewers and ditch the wheel QRs too.

Bear in mind that this still leaves the saddle clamp bolt(s) vulnerable.


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## Touch0Gray (May 29, 2003)

they DO make tamper proof/resistant bolts you know...

Socket Pin-Head Tamper Resistant Screws: Tamperproof Screw


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## rider9 (May 27, 2011)

Or, you could install a quick release bolt for the seat post clamp and take it with you. Seat post and saddle too.


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## JCavilia (Sep 12, 2005)

"Rare earth" magnet?


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## bignose (Sep 15, 2005)

When you lock your bike, run a thinner cable thru your seat rails.


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## savagemann (Dec 17, 2011)

JCavilia said:


> "Rare earth" magnet?


Neodymium magnets, called rare earth magnets.
Very strong and the larger ones can be dangerous when they are improperly handled.
One of the most common uses are inside of computer hard drives.


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## JCavilia (Sep 12, 2005)

savagemann said:


> Neodymium magnets, called rare earth magnets.
> Very strong and the larger ones can be dangerous when they are improperly handled.
> One of the most common uses are inside of computer hard drives.


I know what they are. I was just pointing out that that's probably what he meant when he said "earth magnet". Not all are neodymium. Some are made of samarium and cobalt.

They're used in a lot of things, including hub generators for bike lights, and audio speakers.

I've heard of kids swallowing several of them, and being seriously injured when two magnets in different folds of the intestine pulled together and pinched holes in the gut.

If you leave a a stack of them near a computer they can do a lot of damage.


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## UrbanPrimitive (Jun 14, 2009)

Noose style chain is my answer. Thread the chain as normal through the frame and front wheel, around whatever you're locking to, under the seat stays and lock to the saddle rails. Depending on your setup, a long enough U-lock may be able to lock your saddle to your toptube. Barring that, I'd consider swagging some 1/16" galvanized aircraft cable to make a loop around your saddle rail and a second loop around the tube of your choice, top or seatstay. It could still be clipped with cable cutters, but it's plenty enough deterrent for a thief of opportunity.


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## surly boy (Sep 8, 2011)

Ditch the seat altogether. I know a guy who had surgery in the nether regions and as a result couldn't sit on a bike seat for months. He took the seat and post off the bike rode standing up for about two months and developed very strong legs.


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## bignose (Sep 15, 2005)

surly boy said:


> Ditch the seat altogether. I know a guy who had surgery in the nether regions and as a result couldn't sit on a bike seat for months. He took the seat and post off the bike rode standing up for about two months and developed very strong legs.


That sounds like confirmed "broscience" - Urban Dictionary: broscience

I know a guy who rode a bike and HE GOT CANCER!! Don't ride bikes. You'll get cancer too.


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## Fixed (May 12, 2005)

*or*

If you don't need to remove or adjust your seatpost very often, install the seatpost, use some anti-seize on the clamp bolt threads, tighten down, and then drill out the hex so that it cannot be removed. Then, when you need to remove it, use a bolt extractor. Not very elegant, but probably effective.


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## rider9 (May 27, 2011)

Fixed said:


> If you don't need to remove or adjust your seatpost very often, install the seatpost, use some anti-seize on the clamp bolt threads, tighten down, and then drill out the hex so that it cannot be removed. Then, when you need to remove it, use a bolt extractor. Not very elegant, but probably effective.


I'm not following this. How do you drill out a hex? I am having trouble visualizing what you wrote. Picture?


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## 10ae1203 (Jan 14, 2007)

rider9 said:


> I'm not following this. How do you drill out a hex? I am having trouble visualizing what you wrote. Picture?


use whatever size drill bit matches the hex wrench, i.e. 5 mm (about 3/16") and put the drill into the recess.

drill.

it will drill away the defined walls for the hex wrench to grip.

crude but effective.


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## rider9 (May 27, 2011)

10ae1203 said:


> use whatever size drill bit matches the hex wrench, i.e. 5 mm (about 3/16") and put the drill into the recess.
> 
> drill.
> 
> ...


I get it now. Where I was having trouble was I was picturing a hex nut.


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## Touch0Gray (May 29, 2003)

for pete's sake just get a tamper proof bolt and the correct hex or torx to put it in and take it out.....


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## Plum (Mar 27, 2005)

Fill the allen head with hot glue, will keep it from being an easy target and is reversible. Not infallible, but something to keep them moving onto the next target.

Plum


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## Touch0Gray (May 29, 2003)

all you can do is keep the honest people honest.....


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## Dersnap (Mar 28, 2012)

What about pitlock?
I use them on my wheels. Ist Ihr Fahrrad schon gepitlockt?


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## 10ae1203 (Jan 14, 2007)

Touch0Gray said:


> for pete's sake just get a tamper proof bolt and the correct hex or torx to put it in and take it out.....



but, but, but, wait.

I have a ball bearing and some magnets, and mashed potatoes. 

Or if I fill the hole with wheaties, no one will ever be able to pick them out.

Or wait.

Ok.

I'll stop being a smartass.

Your idea is simple and effective. Practical and clean.


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## Touch0Gray (May 29, 2003)

10ae1203 said:


> but, but, but, wait.
> 
> I have a ball bearing and some magnets, and mashed potatoes.
> 
> ...


as well as being cheap and reversible!
but the mashed potatoes would run a close second


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## logbiter (Sep 14, 2005)

Would that be white or brown gravy on dem potatoes?
Wheaties would invite squirrels, then the raptors would be swooping down on you & your bike... while you fend off said raptors, wildlife & fisheries agents will be giving you hell! where would it end?!


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## Touch0Gray (May 29, 2003)

logbiter said:


> Would that be white or brown gravy on dem potatoes?
> Wheaties would invite squirrels, then the raptors would be swooping down on you & your bike... while you fend off said raptors, wildlife & fisheries agents will be giving you hell! where would it end?!


neither....sweet ta-paters, will match most mikes best...so we are talking butter and MAYBE a sprinkling of brown sugar


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## logbiter (Sep 14, 2005)

Touch0Gray said:


> neither....sweet ta-paters, will match most mikes best...so we are talking butter and MAYBE a sprinkling of brown sugar


even better for the drivetrain!


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## 10ae1203 (Jan 14, 2007)

mmm

brown sugar.

this hasn't degenerated to messing with the normals, has it?


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## 2cflyr (Apr 9, 2002)

10ae1203 said:


> mmm
> 
> brown sugar.
> 
> This hasn't degenerated to messing with the normals, has it?


ibtl


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## Touch0Gray (May 29, 2003)

Bailey271 said:


> Bear in mind that this still leaves the saddle clamp bolt(s) vulnerable.


this is true....and tamper resistant bolts would work there as well


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## Dersnap (Mar 28, 2012)

Touch0Gray said:


> this is true....and tamper resistant bolts would work there as well


Funny how ppl will go through the most complex methods to try something when you can just get something that is proven.

I will once again suggest pitlock as this is exactly what its designed for. Looks good to when I put end caps on.


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## Touch0Gray (May 29, 2003)

lol......no end-caps necessary with tamper proof....even available in stainless!


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## Dersnap (Mar 28, 2012)

Touch0Gray said:


> lol......no end-caps necessary with tamper proof....even available in stainless!


End caps "not needed" but purely cosmetic to make it look better. Pitlock uses a key system with 200 or more different keys. 

On my wheels I just put the end cap to look similar on both sides. You can't open them with out the original key. Seat is similar system with the bolt.


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