Horn

Getting ready to install the horn before I go any further on my rebuild. I bench tested it three years ago when I bought the bike and it worked fine, now I can't get a squeek out of it. Is there any way of repairing one of these things. If not what would be a good inexpensive replacement?

Yes - I don't remember the details but that the whole thing was so simple the fault will be easy to find or so obvious bad ya will just toss out the bee under a bonnet beeper. Must hold-fasten the mount-post rather firmly for it to toot too. Then can diddle the tensioner screw to dial in best it can be. If it worked when last known then very likely will again.

Are you concerned with whether or not your Commando is "original"? If not throw the horn in the bin, or set it aside to sell along with the bike someday when somebody else is concerned with originality.

I bought a PIAA slim line horn and mounted it between my coils. While I wish it blew cars off the road, it doesn't. But it works well enough to leave it there and use it.

Russ

Russ,
Do you think the the PIAA would fit in the curve behind the Z-plate?
Thanks, Bob

I had the stock horn come loose and lock up into the chain once this year. I went to the wrecker and got a Fiamm horn off of a Chevy or Ford.
It was smaller and so loud.
I fitted it on the same hanger and mounted it in the stock location.
Not only is it louder, it fits right between the cradles plates.
So nice having a screamin' horn.
You can't see it anyway being tucked in there.

rpatton said:

Russ,
Do you think the the PIAA would fit in the curve behind the Z-plate?
Thanks, Bob

Click to expand...

Do you mean the radius of the trailing edge of the Z-plate? I can take some dimensions for you if you like.

Russ

Guido said:

I had the stock horn come loose and lock up into the chain once this year. I went to the wrecker and got a Fiamm horn off of a Chevy or Ford.
It was smaller and so loud.
I fitted it on the same hanger and mounted it in the stock location.
Not only is it louder, it fits right between the cradles plates.
So nice having a screamin' horn.
You can't see it anyway being tucked in there.

Click to expand...

Mine did not get to the point of locking the chain but it was rubbing. I purchased a new $1 horn on ebay($2 shipping). Works great. Is loud enough. Does not have the cool sound of the Norton. Mounted on the front of the battery box. I will find a permanent solution but this one solves the issue for now.

It is in a hard spot to get a decent photo, but this is where my horn ended up...

Living in the south and leaving something setting for 3 years is an open invitation for mud daubers

Yes to mud dubbers making me get down and dirty.
Yes to after market placement in crook of Z plate as fashion the Dreer preferred and me too.

I was able to shoehorn in a Stebel Nautilus horn in the stock location. Also added a horn relay. It is so loud that it really doesn't matter where you mount it.

These are sold under the name "Bad Boy" horns at Harbor Freight too. Pretty much the same thing as far as I can tell.

I seem to recall drilling out the rivets that lock the stock horn together (and replacing them with little stainless bolts, with nyloc nuts).

The copper contact points inside simply needing filing flat (to a very slight dome shape ?) and it was as good as new. Seal with silastic or similar, to keep the moisture out.

Any deeper problem and it would have to go to a specialist - Taff the Horn, in Wales UK ??
As mentioned, you can buy little replacements that are far louder,and lighter, AND easier to mount.

I junked the stock horn 20 years ago and mounted a small Framm on the right side coil mount bolt

Guido said:

I had the stock horn come loose and lock up into the chain once this year. I went to the wrecker and got a Fiamm horn off of a Chevy or Ford.
It was smaller and so loud.
I fitted it on the same hanger and mounted it in the stock location.
Not only is it louder, it fits right between the cradles plates.
So nice having a screamin' horn.
You can't see it anyway being tucked in there.

Click to expand...

Guido is on the money here,,,, i have Fiamm horn mounted near coils and no shit it sounds like a trucks air horn ,would recommend.

I mounted one Fiamm El Grande in the stock location. IIRC I had to fab a new leaf plate. Loud is an understatement. Don't forget to use a relay. I think they are only sold in pairs. I've been thinking of mounting the second up front of the coil bracket. One will definitely get the job done, though.

Definitely looking for a replacement. Thanks all.

This one came out of a wrecked chevy; $5 and its loud as hell.... I only wish I took the pair of them!
I already had the relay, but I think that cost about $5 too, and the aluminum ring was $10

htown16 said:

Getting ready to install the horn before I go any further on my rebuild. I bench tested it three years ago when I bought the bike and it worked fine, now I can't get a squeek out of it. Is there any way of repairing one of these things. If not what would be a good inexpensive replacement?

Click to expand...

The stock Lucas horn has an adjustment which sets the gap in the horns points, this adjustment looks like a 4mm pot metal bolt with a jam nut that locks in the adjustment. If you slack off the jam nut and turn the bolt in and out the horn will fire off. Have a fully charged 12v batter handy and a set of ear protection and blow the horn repeatedly with different adjustments for about 3 minutes (I hope you don't live in an apartment), then set the adjustment for the loudest volumn and lock the jam nut. Let the hirn cool for about an hour and test it again, it may need one or two more adjustment before it settles down and becomes consistent.

As others have said the Nautilus is a great horn, there is some bad press out there, but the two I had on an R1200 GS used to make soccer moms drop their cell phones at quite a distance; I referred to them as my phasers.

I like where Hobot has mounted his horn; nice an accessible, very easy to replace. I made an aluminum cross bar for a customer that didn't want to spring for the chassis strip to replace the stock horn that mounts to the two down tubes and hangs one or two horns to the left and right of the coils, but a bit lower; you can also hang driving lights on this bar if you have the power.

RS

You could always do what the previous owner did and mount it like this. Fresh air for cooling, easy access, unlikely to fall off and jam the rear chain...