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Dunlop E-3 and Kumho C/T Sidewall Comparison

4K views 15 replies 6 participants last post by  cwoods 
#1 ·
We changed the rear tire on a sidecar here today. It had a Kumho on it.

We put an E-3 in it's place.

There seems to be some severely misleading information about CTs that have people thinking the sidewalls of a CT are stiffer and able to support more weight.

That could not be further from the truth.

The Dunlop E-3 has a sidewall and general carcass structure that is so hard and rigid, it is hard to believe.

For a test, I took the bare tire (not on the rim), and stepped down on the sidewall. It did not move or deflect.

Then I put both feet on it and stood on it, and the sidewall still did not sink (I weigh 175 in clothes and boots).

Then I went back to one foot, and balanced myself on a desk and then bounced on it will all of my weight. This got it to squish or deflect some.

The sidewall when felt with your fingers, is virtually the same thickness as the tire bead! As you feel up the sidewall going toward the tread, it get THICKER as it approaches the edge of the rolling area of the tire.

As for the Kumho, I suspected it would have very soft sidewalls, because you could push on the side of the saddlebag, and the whole sidecar rig would wag back and forth (while stationary), and you could see the sidewalls shiftiing.

We dismounted the Kumho (at Ken's Tires in Woodstock, GA), and I can't tell you how shocked I was.... but it explained a couple of things.

First of all, the car tire bead was too wide for the motorcycle rim's bead seat. The inner edge of the lip of the bead sat up on top of the safety lock lip of the rim. This is of course, just plain unsafe.

Next was the general construction of the tire. This tire wasn't worn out, and in fact, the owner was the type of guy who wanted lots of rubber over trying to "make the Eagle scream" on a dollar. It had 3,000 miles two wheeling, and 8,000 miles side carring. It had worn down to the first level of two levels of wear bars.

It was so soft and flimsy, that I couldn't believe they would put it on a car, never mind a motorcycle. I could pinch the sidewall with my HAND.

I set it on the floor, and with one foot on the floor, and one foot on the sidewall, I could mash the bead flat down onto the tread! It was a joke.

Next, the entire tread was so soft, that it was more like a thin sheet of rubber. You could wrinkle it like it was a soft sheet of rubber. It was VERY thin. I have never seen a MC tire as soft and flimsy as this tire was.

But what I did figure out is where CT pundits think this tire works better. It is so soft, all the way from the bead and across the crown, that the corner actually crushes and distorts when you push down on the tire.

What it does that they CAN'T see, is it "puckers up" or makes a pocket up into the tire. But I can see how this might lead them to feel it had more grip.

While this is only one brand of CT, I can honestly say I would never put this particular brand on a car, never mind a bike. Never mind the bead doesn't lock fully into the seat! And if this tire ever did go flat.... :shock:

I am sure my observations are flawed in some way. :wink:

We still have the Kumho here if anyone wants to see it when they visit. We'll keep an E-3 around (if we can find one!) as well. :)
 
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#9 ·
When/where were you a phrog?
A friend of mine was a UDT member, then a Seal; first Seal team picked by JFK.
I used to go to the the picnics on Veterens Day with them in Jupiter. Dang, those boys can shoot.
 
#10 ·
Arn Butt Bill said:
When/where were you a phrog?
A friend of mine was a UDT member, then a Seal; first Seal team picked by JFK.
I used to go to the the picnics on Veterens Day with them in Jupiter. Dang, those boys can shoot.
Bill,
I was never in UDT or a Seal. I spent 21 years as a Marine and 19 years of that as an H-46 Crew Chief. The term "Phrog" is a nickname for the H-46. The H-46 first saw service in Vietnam and continues surving our country today in Afganistan and Iraq.
 
#12 ·
Re: tire

ANGUS said:
Max what is your opinion of the Dunlop run flat sidewall just curious it seems that several from the dark side prefer this tire.
Haven't seen one yet. I think run flat is a brilliant idea for motorcycles. Just not with a square tire.

I had lunch yesterday with Pirelli North America's motorcycle tire manager. He said as a company they will never even comment on the CT issue. It is beyond their comprehension. :lol:
 
#13 ·
cwoods said:
Arn Butt Bill said:
When/where were you a phrog?
A friend of mine was a UDT member, then a Seal; first Seal team picked by JFK.
I used to go to the the picnics on Veterens Day with them in Jupiter. Dang, those boys can shoot.
Bill,
I was never in UDT or a Seal. I spent 21 years as a Marine and 19 years of that as an H-46 Crew Chief. The term "Phrog" is a nickname for the H-46. The H-46 first saw service in Vietnam and continues surving our country today in Afganistan and Iraq.
Uncle Sam's Misguided Children are O.K. too, but you'all don't shoot as good as the Seal's when you're drunk...
 
#16 ·
Arn Butt Bill said:
cwoods said:
[quote="Arn Butt Bill":1opkxryo]When/where were you a phrog?
A friend of mine was a UDT member, then a Seal; first Seal team picked by JFK.
I used to go to the the picnics on Veterens Day with them in Jupiter. Dang, those boys can shoot.
Bill,
I was never in UDT or a Seal. I spent 21 years as a Marine and 19 years of that as an H-46 Crew Chief. The term "Phrog" is a nickname for the H-46. The H-46 first saw service in Vietnam and continues surving our country today in Afganistan and Iraq.
Uncle Sam's Misguided Children are O.K. too, but you'all don't shoot as good as the Seal's when you're drunk...[/quote:1opkxryo]
Well, if you think that a Marine can't shoot as good as a Seal, why don't you stand here and I will move 300 yards away . . . oh never mind. :beer2: Next one is on me.
Semper Fi
 
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