stealth bike

motor in a plastic milkcrate, shag carpet for sound adsorption, added off the shelf muffler

 

[Dave C]

That's a scream, very clever idea. Does it overheat?

 

[Deleted member 12676]

Too too cool!
Can you hear it 20 ft away?

 

[rockbass]

just went around the block -seems okay. added muffler - takes out sharpness of the exhaust sound but still can hear it. not sure how much the carpet helps. attached picture shows milkcrate is open top & bottom, also partially open front & back, think this should be enough for adequate air flow. used existing carburator inlet, turned 180 deg. & epoxyied on a 45 deg 5/8" copper street elbow. exhaust has 90 deg 3/4" copper elbow brazed at exit flange. motor is rubber mounted on rack but my test run showed serious vibration at mid range speed. added dual brake lever - work great.

 

[professor]

I think there is a post somewhere here about quietiing the HT.
Adding deadening material to the clutch cover, a sound extension /box? to the intake, rubber bits between the fins.
I have found the more mufflers and legnth -the quieter the sound.

See if you can bolt the engind down solid, this should help lower the vibes.

You may be able to delete the carpet material for cross cooling when the snow goes away, after all, the black engine will be difficult to see.

 

[lowracer]

I like it!
I may need to do something like this to avoid getting pulled over.
Thanks for sharing
-Lowracer-

 

[rockbass]

appearance is everything,
plan to add a rear view mirror for smokey detector.
always where a helmut, stay under 30 kph and should not attract attention.

 

[Htown]

appearance is everything,
plan to add a rear view mirror for smokey detector.
always where a helmut, stay under 30 kph and should not attract attention.

Killer. I was thinking you might be able to use some of the negative noise technology that is employed in loud offices. I think it would work for noise with a constant pitch.


http://www.acousticalsurfaces.com/white_noise/white_noise.htm

 

[motorpsycho]

ha ha, let the engine get good & hot, and i bet that carpet goes up in smoke.
the exhaust is actually touching the carpet, and that pipe can and will get up to 250 degrees F. if not more.
I don't think you will have enough air flow to keep the engine cool because these things get pretty darn hot, and with the gas tank being right on top of the engine, I would not be surprised if the engine gets vapor lock from the heat.

 

[Htown]

ha ha, let the engine get good & hot, and i bet that carpet goes up in smoke.
the exhaust is actually touching the carpet, and that pipe can and will get up to 250 degrees F. if not more.
I don't think you will have enough air flow to keep the engine cool because these things get pretty darn hot, and with the gas tank being right on top of the engine, I would not be surprised if the engine gets vapor lock from the heat.

I am pretty sure the milk crate is perforated enough so as to get enough airflow, I would think using a hood liner material might be better choice of sound deadening materials.