Mounting a switch to handle bars?

[slowmotion]

Are your bars straight or drops? How big is that bike horn BTW? A rough diameter.

Edit: Sorry I read the ebay ad more carefully. 100mm diameter! Holy Moly!

 

[HovR]

Using drop bars. The horn I originally tested the battery on was around 10cm, although I could go down to 7cm moped horn if needs be.

 

[slowmotion]

I think you should consider an "electronic sounder" rather than a horn. Something like this...
http://uk.rs-online.com/web/p/electronic-sounders/2487162/
The current consumption is probably a lot less than one hundredth of a motorbike horn. That means that your battery can be piddlingly small, as can the wiring and switch.

BTW, I just picked that sounder after a very brief search. There are loads more that might be smaller and more suitable in other ways.

 

[HovR]

Apart from lower current, and less wiring, are there any other significant advantages?

To be honest I'm not very concerned about the battery size, as the one I have weighs less than 500 grams, and will power a medium size motorbike horn (Although the smaller horn linked below may be better.)

All of my wiring will be in a saddle bag, apart from the horn which will be attached near the rear brake, and the switch which can be very small with thin wiring if I use a relay. A moped style horn, such as this one, is quite small and very easy to mount.

 

[slowmotion]

http://www.instructables.com/id/Putting-A-Car-Horn-On-Your-Bicycle/

 

[HovR]

I've read that article, unfortunately it doesn't contain any tips on mounting. I already know how I can easily mount the actual horn unit - Just have to figure out the switch. Seems like NT's option is the best so far.

One thing I find interesting is the varying of opinions between different horn-fitting cyclists as to whether a relay is needed or not. I think I will probably use one, just so I can route smaller cables up to the front switch.

 

[andrew_s]

I'd put the switch in a small ABS box like those linked earlier, and mount the box on a repurposed handlebar clamp - eg this bottle cage clamp or perhaps a Hope Vision 1 clamp.
I used a clamp from a Byka Owl light that held the box just in front of the bars rather than on top (the box holding two switches for twin halogen dynamo lights)

 

[Arch]

I came across an interesting switch set up on a bike outside Sainsburys today:

Seemed to be for the interesting rear light/indicator set up:

Not exactly subtle!

 

[HovR]

I came across an interesting switch set up on a bike outside Sainsburys today:

<img removed>

Seemed to be for the interesting rear light/indicator set up:

<img removed>

Not exactly subtle!

Thanks for the images! Interesting setup - Wonder if they are more effective than Bicygnals!

 

[mattsccm]

Why not use the normal horn button as found on many motorcycles. Not the ones that are part of normal switch gear but the individual ones made ofr older bikes. Plenty about that are tiny or look for a kill switch. About a fiver. The are about the size of the top joint of your thumb and rubber covered. Where to get them. Normally the same place as the horn. Try Vehicle Wiring.

 

[IT_Dummy]

Buy two power beam led lights
fit the brackets to your bike ( don't use the lights)
Make a plastic plate, drill hole for switch and fixing holes
Use longer fixing screws for bracket
The plate goes over fixing screws. Use a nut to fasten each side
(cost £3-00 for lights and brackets -e-bay)

 

[Steve Malkin]

Surely something like this:
http://www.ebay.co.uk/itm/Motorcycl...cycle_Parts&hash=item519681c324#ht_684wt_1163
Would be a better option than some bodged up plastic box clamped to your handlebars?

 

[HovR]

Surely something like this:
http://www.ebay.co.uk/itm/Motorcycl...cycle_Parts&hash=item519681c324#ht_684wt_1163
Would be a better option than some bodged up plastic box clamped to your handlebars?

My original plan was to not use a relay, and instead use thicker wire and a higher rated switch. The amperage the horn would draw would likely destroy a switch such as the one you have linked.

My latest plan was to use a relay (which would allow me to use a switch such as the one you have linked) and fit all of the wiring into a saddle bag, although after some testing I've found the saddle bag won't go onto the seat post with my Mars 4.0. I don't want to put the Mars onto the bags light loop, as I've lost many lights that way.

So now my options are to either use a frame fit bag, or abandon the project!

 

[Steve Malkin]

So now my options are to either use a frame fit bag, or abandon the project

Shame, It would have been interesting to see how this one turned out, though I can't help thinking that the airzound approach is more suited to bicycle fitment, no batteries, wires, relays or anything else, and it's probably louder too!

 

[HovR]

I have looked at the Airzound, but I have a few issues with it. First being the quality - I've heard lots of people say that the quality is a bit on the naff side, loosing its air tightness after a while. Secondly I don't have much room on my bars, and didn't want a huge air horn attachment on there. And thirdly, the constant refilling (and the fact I don't actually have attachments for a bottle cage on my Dawes Echelon).

I guess each system has its advantages and disadvantages. For an indication of how loud my setup is/was, just go honk a stock motorbike horn. The battery powered one with no issues to the same volume as the motorbike's battery.