alarmed!

[alsmith]

Any recommendations for alarms from anyone?

I came across a thread from 07 mentioning the CyberNexus but it seemed like they had gone. Are the alarms still working? Replaced? Or has your opinions on usefulness of alarms changed?

I have been sort of looking but I think it's reaching decision time.
One of those I was more seriously looking at was the one that fits in the handlebar tube (shadow alarm) but they told me you only get one key. I haven't got an answer about a second one yet, but I think you should always have at least one spare in case of loss. The other thing is that you need to enlarge the handlebar grip holes to get the key in at one side and noise out at the other side- the downside being I was considering one of those end of handlebar mirrors- winkku but it would mean the shadow alarm couldn't be used.
At the moment I kind of think the mirror is the better option.

So thoughts and experiences welcomed. Are alarms worthwhile and what do you have? Any drawbacks? And has anyone got the Winkku mirror?

thanks!

 

[flecc]

I've got one which works ok as long as the weather isn't too cold. Like many of them it uses a PP3 battery and these really suffer when the temperature is low, making the alarm unreliable then.

It's not available any more, but on it's old Amazon link there's some different ones to give a choice:

Bike alarms at Amazon
.

 

[torrent99]

Advice about alarms....
forget em.... everybody ignores them anyway. So unless your are always going to be in earshot & ready to come running everytime it goes off, it's not likely to do any good.... just my two penneth worth...

 

[rog_london]

Advice about alarms....
forget em.... everybody ignores them anyway. So unless your are always going to be in earshot & ready to come running everytime it goes off, it's not likely to do any good.... just my two penneth worth...

Absolutely right, I'd say.

The main problem - there's nowhere on a bike that a suitable alarm can be hidden, and still be loud enough to be effective.

If I didn't know better, I *would* also have said that a small battery would not power an effective alarm sounder, if I didn't have experience of (commercial) radio fire alarm sounders driven off two 3.6 volt non-rechargeable lithium cells (not the coin type, the ones which look more like a fat AA battery) which are unbelievably loud and will keep that racket up for about two hours.....

They are physically quite large, though. About a 4" cube. Not much good for our purpose here, therefore.

Incidentally, slightly off topic, if rechargeable lithium technology cells and batteries ever catch up with their non-rechargeable counterparts, we really might be on to something for battery-powered vehicles - there is a lithium cell which is exactly the same size as a D cell - though not electrically interchangeable because it's 3.6 volts instead of 1.5 volts - which is rated at 40 amp hours.

It's not a high discharge rate job, being mainly valued for its charge density and its shelf life (80% capacity after 10 years), but an amazing thing for all that. Don't get excited - remember it's not rechargeable!

Rog.

 

[alsmith]

Absolutely right, I'd say.

The main problem - there's nowhere on a bike that a suitable alarm can be hidden, and still be loud enough to be effective.


Rog.

What about the one I linked? Hidden in the handlebar. If I could see/hear one....
The ebay choice seems better than amazon but none really appeal.

 

[eddieo]

I think they are handy if you are within earshot.In a shop or restaurant etc....and hopefully enough to surprise and scare of amateurs.

there was a few threads before on the subject and I bought one of these:

Bike Alarm | Bike Alarm | Property Protection | Security Products | Safetyshop

 

[Mussels]

Some locks have an alarm built in so they are in a good position, finding a decent lock with a built in alarm is a different matter.

 

[rog_london]

What about the one I linked? Hidden in the handlebar. If I could see/hear one....
The ebay choice seems better than amazon but none really appeal.

The problem is shown up by the video - it's not loud enough. The background noise was enough to almost drown it. I'd have been more impressed if there were any dB readings quoted. If someone rode off on a beeping bike, who would pay it any attention? I wonder how loud it would be after a large lump of chewing gum, or a cork, had been pushed into the end of the handlebar?

I suppose it's better than nothing, but not much. I'd still have more faith in a serious cable lock.

Even motorbike alarms are not usually all that loud (unless they're linked to the horn), and they have many more places available where they can be concealed.

I think that to be effective an alarm has to be loud enough to be an embarrassment to the would-be thief. 'Beep-beep-beep' doesn't do it.

Rog.

 

[flecc]

Mine screeches 110 dB from sounders at each end:

 

[eddieo]

Mine is loud as well!

 

[rog_london]

Mine screeches 110 dB from sounders at each end:

That's better. Those look like what we call 'Banshees' in the fire alarm business - a trade name for that particular design. 110dB (presumably right next to it) is pretty good. Electronic fire alarm sounders are amazingly efficient - you can get that sort of sound level with around 10-20mA on a 12 volt battery. There are some models which will work on anything between about 6 and 24 volts, and just take a bit more current at the low voltage end, without losing much in the way of volume.

You couldn't hide those down a handlebar, though!

There used to be one small one around which would have commended itself for bikes, although I haven't seen one for a while - the trade name was 'Cybertone' and they emitted a piercing whistle.

They were about 1.5'' in diameter by about 3/4" deep, and mounted with a single fixing nut through a hole well under an inch in diameter - so if you mounted one in a panel, there was almost nothing to see from the front, in spite of the fact that all the sound came through the same fixing hole.

Just Googled it - and they're still around. Based in Brighton. I doubt they'd sell you one on its own, but worth a look.

http://www.hbl.co.uk/images/pdf/Cybertone Range.pdf

Rog.

 

[flecc]

Something of interest to you Rog. During my working days when I could be away from home for extended periods, I had special protection for all my home electronics in addition to the home alarm.

I built into each item a small 110 dB screecher with low level trickle charging of it's battery and base magnet triggering. Pick up anything, TV, VCR, amplifier, tuner etc and it's screecher would kick off and run for the duration of the whole battery charge. Each had a reset switch concealed within one ventilation slot, but needed the knowledge of which slot and the L shaped tool to reset the switch.

As usual with cheap sounders they all had differing pitches so together sounded like hell on earth. No burglar ever tried, but I'm sure none would have had the guts to carry away the goods.
.

 

[wotwozere]

Hi

Can you sell me one of them it would be great in my estate, scare all the kids away. My friend said I should tie cs gas spray can to my handlebars to prevent attacks.


thx

Bob

 

[rog_london]

Something of interest to you Rog.


No burglar ever tried, but I'm sure none would have had the guts to carry away the goods.
.

Sounds good to me! I keep the e-bike in the house, and there's no rear access except through neighbours' houses, so hopefully things are reasonably secure round here. I haven't heard of anyone local being burgled.

Bloody hell - what am I saying? That's tempting Sod's Law....

Rog.

 

[alsmith]

Thanks for all the thoughts.
Well, thinking about it maybe a different route may be worth looking at. I have a small topbox fitted for my LiFePO4 battery when it arrives so maybe fitting something in here could be a better option. I've not seen 36V sirens or alarms so unless I could source an inexpensive DC-DC convertor then a self contained unit will still be the way to go, but hopefully with more options.

 

[Fecn]

I've got one which works ok as long as the weather isn't too cold. Like many of them it uses a PP3 battery and these really suffer when the temperature is low, making the alarm unreliable then.

If you're looking for a low temperature battery, try the primary (non-rechargable) lithium ones such as the Energizer Ultimate range. I use them in my weather station because they're good at sub-zero temperatures.

 

[rog_london]

Thanks for all the thoughts.
Well, thinking about it maybe a different route may be worth looking at. I have a small topbox fitted for my LiFePO4 battery when it arrives so maybe fitting something in here could be a better option. I've not seen 36V sirens or alarms so unless I could source an inexpensive DC-DC convertor then a self contained unit will still be the way to go, but hopefully with more options.

If you wanted something seriously loud, and like a bit of DIY, you could probably construct some sort of alarm yourself to fit inside your top box. Don't ask me to do the design - I don't offer solutions, just daft ideas!

Most fire alarm type sounders are rated to at least 30 volts (many fire alarm panels when powered from the mains run on about 27.5V which is convenient for 'floating' a 24V SLA set), and because of the low operating current, you would probably simply be able to incorporate a series resistor to drop the voltage. A *loud* sounder would probably do about 25ma at 24V, which is only about 0.6 of a watt - so a suitable resistor would be about 470 ohms 1/2 watt - very easy to obtain.

For everyone's benefit - any electrical wholesaler will sell you a fire alarm sounder. They all come with wiring diagrams, specification sheets, etc. Most of them can be configured for different volumes and lots of different sounds.

In case you think 0.6 watts of audio is not much, bear in mind that these things are something like 80% efficient in converting electrical energy into sound. A good quality hi-fi speaker may have an efficiency of less than 1%. Basically, subjectively, not much electrical power equates to a hell of a racket with efficient conversion.

Just one problem - you'd need to incorporate some sort of time-out, because it would run for weeks on the sort of battery you'd have on an e-bike! The neighbours would not be impressed. FYI, if you have a burglar alarm with an outside bell or siren and it's in a built-up area it has to time out after 20 minutes.

Rog.

 

[flecc]

Vehicle regulations require a car/motorcycle alarm to cut after 30 seconds.

e-bikes are exempted from most vehicle legislation and that may apply to alarms also, but I suppose "disturbing the peace" could apply.
.

 

[Mussels]

This may help a bit.
Burglar Alarm Kit > Maplin

 

[rog_london]

Vehicle regulations require a car/motorcycle alarm to cut after 30 seconds.

e-bikes are exempted from most vehicle legislation and that may apply to alarms also, but I suppose "disturbing the peace" could apply.
.

It sure would if you had a fire alarm sounder and it kept going! I must admit I was aware of the 30 second limit. I was thinking that if you did a DIY setup you might want to have a quick reset if it were parked in a public place, and 20 minutes if it were within your premises.

Motorbike ones are also a bit more complex than that - they usually give a pre-alarm warning (a few loud beeps) and only launch into full alarm if the vehicle continues to be interfered with. Also, they give up completely after some 10 activations. Presumably if you haven't attended by then, it becomes a nuisance. Wind can set them off, and you wouldn't want repeat alarms all day and night. I believe modern car alarms also give up after a while, for the same reason.

The DIY route is not so simple, therefore.

Rog.