Is this going to far?

[Byron]

After a recent thread about almost being backed over by a truck I decided to finally put a Stebel on my bike. In doing my homework on the subject I felt I had to solve a filtering issue. You might say what filtering issue. Well, I was concerned about debris getting inside the compressor side of the horn and causing it to fail. I remember seeing somewhere about using a piece of tubing attached to the intake to keep water out but it didn't really address debris as far as I was concerned.

Here is what I came up with:

http://www.st-owners.com/pp_gallery/data/593/DSC02107.JPG

It is a Uni Filter CP-101 Breather 5/16" clamp-on filter. The filter is not oiled according to the manufacture and is made of compressed foam.

I haven't mounted the horn yet but will take care of that task this weekend. For those that are interested I've posted some additional photos in my gallery (http://www.st-owners.com/pp_gallery/showgallery.php?cat=593).

So, is this going to far? :)

[dreddd2000]

Not if it makes you happy or gives you peace of mind. :)

[George]

As long as it doesn't restrict intake to the point of strangling the deciBels. Keep us poSTed. (The capitol B is correct, part of honoring Alexander in the old days.)

[Gonzo]

HI, Byron,

I just got my Stebel installed and I was wondering about the same issue. I was about to go find some tubing. I thought the purpose was just to keep water from splashing into the air intake.


I used the special nut you made, but in the process I came up with another idea, because the screw goes thru the mirror mounting hole, the screw should have some threads removed to work better.

gonzo

[STindy05]

Yes:)

[John Anthony]

Byron,

Good attention to detail as more often than not, it's the little things that bite us in the butt. I like your approach.

John

[Gonzo]

This is from a guy who has the K & N air filter, a reusable oil filter, etc, etc, etc. So what's unusual that he would filter the air to his horn?

Maybe next he will get a helmet air filter.

gonzo

[Byron]

I'll let everyone know if I can detect any difference in deciBel output once it's mounted. I may have a deciBel meter to check it with. Now, where did I put that darned thing?

To many openings with the helmet on to effectively filter the incoming air. I'll just have to rely on the nasal hair to do its thing. :)

[tommyboy]

Considering where most of us are mounting the Stebel, I think getting debris in the horn is not very likely.

[AzDesertRider]

As long as it doesn't restrict intake to the point of strangling the deciBels. Keep us poSTed. (The capitol B is correct, part of honoring Alexander in the old days.)

DeciBel..... Very cool piece of trivia for the day...

[Gonzo]

I suppose you're right, Byron. After all, a helmet filter would only be for your benefit and won't help the motorcycle one bit.

gonzo

[alphafang]

Da**ed it
Never thought of that (debris) and I've mounted mine low down in the fairing.
Maybe I should get a filter too.
And NO I don't think it's going too far.
Thanks
Paul

[wjbertrand]

That looks like a small K&N. I think you'd be better off with an OEM paper one. :D

[Rob Hephner]

Yea, for all the hassle I doubt it is worth it, but hey its you time and bike. Right?

For what it is worth I mounted my originally with the mouth of the horn up. I went to beep at someone to say hello after I had washed the bike and found the horn was full of water.

After the trip I pulled the horn, mounted it correctly and it has worked fine without issue for 2 years.

[Mark]

How about you just mount a brass barb on the side of the air box and run a tube to it...

Mark

[Gonzo]

OK, let me bore you a little. The common abbreviation for deciBel is dB.

It's a logrithmic scale, using the 0 dB point as representing one milliwatt of power across a 50 ohm load.

The human ear can just barely detect a one dB change. 3 dB change is a doubling (or halving) of power. So if the Stebel is 129 dB, that means that the power has been doubled 43 times from the zero dB point.

Zero dB is not very loud, but it sure gets louder as you go up in scale.

gonzo

[Byron]

How about you just mount a brass barb on the side of the air box and run a tube to it...

Mark

I nixed the airbox connection because I figured the engine would try and suck air in from the horn instead of the other way around. :)

[Mark]

That's what one way valves are for!
(even a 'flap' valve! :))

Mark

[Gonzo]

You're probably right about that, Byron, and the result would be a weaker sound from the horn. Ditto if there was a valve in the line. That would also contribute to a weaker horn. Now if you could just route the horn output to your helmet...

gonzo

[STindy05]

I think youse guys are working way to hard for a $35 horn. If it stops working, replace it. I doubt you will have that much trouble with the horn.

[st13fundred]

I used the special nut you made
gonzo

Vas iss das spezial knutt?;) (I really did do a search before asking.)

[Byron]

"Vas iss das spezial knutt? ;) "

The mounting hardware supplied with the Stebel horn is a M8-1.25 nut and bolt that take a 13mm wrench. You install the head of the bolt into the recess and hole on the back side of the horn and after putting the bolt through your mounting hole on the vehicle secure it with the nut.

When mounting the horn to the upper front faring support frame of the ST1300 near/behind the right mirror would require you to drill out the existing hole that is already there with a 5/16" drill.

I REALLY HATE to permanently modify things if I can avoid it. So here is what I did to solve this problem:

I tried to find some 13mm hex stock locally but had no success. My plan was to cut it to lenght and then drill and tape it for a M6-1 bolt which would fit the existing hole in the faring support. Basically making it an over-size nut. What I ended up doing was locating a non-hardened bolt head that required a 9/16" wrench and cut if off the bolt. I then drilled and tapped this with a M6-1 thread. I then ground off .025" from 4 adjoining flats of the now nut. This reduced it from the original 9/16" (.5625") size to 13mm (.5118") in order to fit the recess on the horn. The unground surfaces positioned down and the ground surfaces are the sides and top of the recess. This keeps the bolt hole centered in the original location.

What this ultimatelly allows you to do is use a M6-1 bolt to mount the horn through the original hole in the faring support.

Hence, "iss das spezial knutt!" :D

[BridgeMan]

Yikes, Byron--some pretty precise machining numbers there. I'll bet you might even carry a micrometer in the tool pouch, just in case you have to make some repairs while on the road?! I'm a "plus-or-minus a foot" guy myself, from too many years of working with bridge contractors.

[st13fundred]

Wow, that's quite a solution! Thanks for explaining it so thoroughly.

I REALLY HATE to permanently modify things if I can avoid it. :D

I completely agree with that statement. That's why I made a completely reversible mounting bracket for installing my Centech AP-2 fuse block (another thread).

So, yes, I did have some hesitation about drilling out that hole in the support frame to help mount the Stebel horn. In this particular case, my concern wasn't about making the hole larger because 1) it was already there (it wasn't a new hole) and 2) it wasn't being used for anything else. So what was my concern? Drilling out the hole removed the paint that was there to provide corrosion resistance. I painted the drilled out part to so there would be at least some sort of protective barrier.

For the same reasons, I also used a stainless steel M8 x 20mm button head bolt, ss lock washer, ss flat washer, and a ss M8 nut. I too put the nut in the Stebel "channel", with the bolt & washers on the outboard side of the fairing support frame.

[Gonzo]

In post #4 where I mentioned Byron's special nut, I should have also mentioned I used a fiber washer between the horn flange and the fairing so the fairing would not get scraped up.

The fiber washer is one which is used for my CO2 bottle in my beer tapper. It's just the right size and the hole is big enough. I usually have several on hand at any time.

gonzo

[Byron]

So many ideas and so little time and money! :)

[Byron]

Well, I just wanted to update everyone on how the air filter worked on the Stebel. I finished the install yesterday. Mounting it on the right side behind the mirror inside the faring. Power is supplied through my AP-1 with a 20A fuse over 14 ga wire controlled by a sealed relay and triggered by the factory horn connectors. The relay was mounted above the right side horizontal headlight adjuster with the screw that holds the headlight assembly near the right edge. It was a close fit but everything went back together just fine.

Before putting the skins on I found my sound meter. It is a Realistic 33-2050 from Radio Shack. With the scale set at 120 dB I gave the horn a blast. The meter was held out at arms length pointed at the back of the horn since the trumpets face the left. I got 122 dB on the meter and that was with the filter in place. To see if the filter was holding back the horn I removed it and ran the test again. I got the same 122 dB.

So I guess I lucked out with this mod. The filter will keep dust and debris out of the horn and it does not reduce the noise level one bit. :)

Where the horn is mounted it is protected from water and with the filter it is now protected from compressor stopping dirt. :D

[nybryan]

i used some hose clamps to attach mine i would have used zip ties if i didn;t have hose clamps lol simple is as simple does