Can someone explain a mystery quiet?

Tom Wesenberg

Tom Wesenberg

Well-known member
That's right, I have a mystery quiet, NOT noise. Just returned last night from a 600 mile trip to S.D. to bury my mom, and to take part in the celebration for the small town where my dad grew up and ran a small dairy with his dad.

On many of the main blacktop country roads there is a rumble strip on the edge of the road that will alert you if you leave your driving lane. Just for fun I ran my Model A on the strip to see how it would sound. There was no rumble or vibration. If I didn't know I was purposely driving on it I wouldn't even know it was there.

I mentioned this to several people, but no one can explain it. All I can think of is it has to be bias ply vs. radial tires. My tires are very old and I thought between the old tires and being narrow, it might make more noise, rather than being quiet.
 
Tom, I was coming back from French Lick and when coming down Rt. 22 into Easton PA they also have rumble strips. I did not feel them, and think it is because the tires are so skinny.
 
My guess is that the resonant frequency of the rumble strip cancels out all the things vibrating on the Model-A, kind of a extended bituminous damper. My Dad almost gave up driving after a few near-misses at going off into the timber. Then the highway dept started putting in the rumble strips and he decided it was safe to hit the road again. Go figure.

Personally, when things suddenly go quiet I quickly start to wonder about what is going on. I recall that those old Chevy Stovebolt 6's would go very quiet just before the rod went through the block.
 
my guess is that the tires are so tall that they roll on top of the strip and never fall down between the notches,
 
But... when a semi tire hits 'em....they are LOUD. try it again in Minnesota. maybe the ones in S.D. are defective.
 
Preacher said:
But... when a semi tire hits 'em....they are LOUD. try it again in Minnesota. maybe the ones in S.D. are defective.
Click to expand...

This was in Minnesota, just north of Buffalo. Maybe they are all filled with salt residue. LOL
Actually last night they were filled with water from the rain that went through. The girl in front of me drove over them a couple of times and the water really flew. I didn't realize they held that much water in each dip.
 
I have noticed it also, the rumble strips approaching a tool booth are just a "bump", I think the spacing is designed for modern cars suspension, the superior transverse leaf spring suspension of the model A dampens it so you barely feel it as 1 bump.

Actually I think the vibration frequency that the rumble strips are designed for is too high for the A suspension to respond ---so you feel it as just 1 bump
 
Tom, sorry to hear about the passing of your Mom. My condolences.

We have those strips on many of the Hiways in Wisconsin, but I don't recall if I ever drove on them with my "A". I usually travel on secondary roads with the "A". I'll have to try it some time and let you know.

As an aside, the EVR seems to be working great. Thanks, Don/WI
 
Sorry to hear about your mom Tom. That was quite a trip in the phaeton. I've noticed also the rumble strip lack of noise and vibration with my 29 coupe. I think it has to do with the tire diameter, higher air pressure and narrow tread width. I was surprised too. I guess we can't rely on those strips to keep us awake.
 
Tom Wesenberg said:
That's right, I have a mystery quiet, NOT noise. Just returned last night from a 600 mile trip to S.D. to bury my mom, and to take part in the celebration for the small town where my dad grew up and ran a small dairy with his dad.

On many of the main blacktop country roads there is a rumble strip on the edge of the road that will alert you if you leave your driving lane. Just for fun I ran my Model A on the strip to see how it would sound. There was no rumble or vibration. If I didn't know I was purposely driving on it I wouldn't even know it was there.

I mentioned this to several people, but no one can explain it. All I can think of is it has to be bias ply vs. radial tires. My tires are very old and I thought between the old tires and being narrow, it might make more noise, rather than being quiet.
Click to expand...

Tom,
That's an interesting little puzzle. Have you driven on those very same strips with a modern car, so you KNOW they make noise?

Here's an interesting pictures indicating style of rumble strip matters. Also mentions that trucks and buses make more noise, so, maybe in the small tire limit there is no noise. This scuttles the idea that larger diameters are quieter!

I doubt that tire diameter is determinant; there's just not much difference between Model A and modern tires' outer diameters. Must be tread width--whether or not air being compressed can travel the distance to get out on the side, maybe (WAG, in case you didn't recognize it).

I wonder how much tread pattern matters. Are you driving Goodyear diamond treads? That's a pretty unusual pattern.

Steve
 

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steve s said:
Tom,
That's an interesting little puzzle. Have you driven on those very same strips with a modern car, so you KNOW they make noise?

Here's an interesting pictures indicating style of rumble strip matters. Also mentions that trucks and buses make more noise, so, maybe in the small tire limit there is no noise. This scuttles the idea that larger diameters are quieter!

I doubt that tire diameter is determinant; there's just not much difference between Model A and modern tires' outer diameters. Must be tread width--whether or not air being compressed can travel the distance to get out on the side, maybe (WAG, in case you didn't recognize it).

I wonder how much tread pattern matters. Are you driving Goodyear diamond treads? That's a pretty unusual pattern.

Steve
Click to expand...

Yes, the modern car gives a very good warning when I did the same drive over the rumble strips. The rumble strips are pockets cut into the blacktop, and as mentioned earlier they are deep enough to hold a fair amount of water as witnessed by the girl in front of me driving off the side of the road twice. I didn't get out to measure, but I'd guess each pocket is about 3 inches wide by about 8 inches long and an inch or more deep.

BTW, the entire 600 mile trip was great and I can't begin to count the number of thumbs up and waves from all the drivers. The only bad driving was by an old man. While going through a small town he waited until I was just about in the intersection, then casually pulled right out in front of me.
After living in MN and S.D. for so many years I have come to realize that many older drivers drive like they are on a suicide mission.
 
Tom,

I'm sorry to hear about your mom. That 600 mile trip was probably about he best therapy to think about past times and family memories of your family.

Sorry I don't have an answer to the mysterious silence.

Richard
Anaheim CA
 
Tom this is easy after being born your model a road some of the worst roads in history, So I'm sure its just thinking wow this is great road just a little rutting, did you solo the trip are were there others
 
I think it is in the shocks. Modern shocks are a straight connection to the frame/body instead of a link and they control the speed of movement of the suspension. Model A shocks have the connecting link and the arm and act more like a soft cushion for the suspension. I think sound will travel through the direct connection better and will be absorbed better by the mass and right angle connections of the Model A.

Tom, sorry about your Mom, but remember the good times. Nobody can take those memories away from you.
 
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