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Old 03-05-2003, 06:57 PM   #1
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Default Foam Density Comparisons

A while ago I saw that somebody posted a link to where somebody had taken a durometer I beleive and tested a whole bunch of different tires from many manufacturers and posted the results and comparisons in a chart. Would anybody happen to know the link or have saved this chart?

I am particularly interested in the comparisons between Jaco and TRC foams...will Jaco's "double purple" or "purple" be the same as TRC's? Or will there be a slight difference between them?

Thanks for the help!
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Old 03-05-2003, 07:10 PM   #2
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I haven't seen that post, but you can get a durometer easy. Just find a racing products supplier. It's like a little $60 tool.

-Leon
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Old 03-05-2003, 08:54 PM   #3
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Look at the top of the screen and you will see a search option. Might help...
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Old 03-05-2003, 08:56 PM   #4
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Well i couldn't give you exact durometer values, but in my own experience, Jaco foams are a little bit softer than TRC. Some 12th scale racers might disagree, but this is what i've found in touring, just my 2 cents.
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Old 03-05-2003, 08:57 PM   #5
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Quote:
Originally posted by Leon
I haven't seen that post, but you can get a durometer easy. Just find a racing products supplier. It's like a little $60 tool.

-Leon
A quality Durometer is going to cost about $300! (a Friend just bought one)
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Old 03-05-2003, 09:22 PM   #6
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We're testing RC car tires... not F1 tires. I thought the idea was just to get a relative value anyway. Isn't that how most RC stuff goes?
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Old 03-05-2003, 09:23 PM   #7
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A quality Longacre Durometer guage is $61.99 with a pouch. My parents sell them in their go-kart shop.
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Old 03-05-2003, 09:41 PM   #8
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Yup. That's what I'm saying. The Longacre unit is good enough for people who race big cars with tires that cost more than the whole RC car can live with a $60 tool. How can that not be quality enough for an RC car?

-Leon
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Old 03-05-2003, 09:46 PM   #9
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Default Foam Density Comparisons

Do you guys realize that to accurately check Foam tires (this IS the idea, right) you need a gauge calibrated to the range of our Foam tires.
Rubber tires are measured on a completely different shore range. (there are like 4-5) Last time I checked, Go-Karts still used Rubber Tires.
If your going to check the Shore of your Foam tires. Why would you even want to if the reading is not going to be accurate.?

Last edited by popsracer; 03-05-2003 at 09:51 PM.
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Old 03-05-2003, 09:50 PM   #10
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That makes sense. Thanks for the clarification. Lucky I won't be using foam tires for a while.
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Old 03-05-2003, 10:32 PM   #11
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Maybe next time I'll read the entire post. However, as long as you use the same tool or scale all the time, it does not matter what scale you use. The purpose is to see which tire is harder or softer. It may not read 40 like a normal purple, but if they both measure 30 then I know they are the same. Just my theory.
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Old 03-05-2003, 11:33 PM   #12
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Quote:
Originally posted by gatrbite
However, as long as you use the same tool or scale all the time, it does not matter what scale you use.
Sure it does. I'd be surprised if a durometer for go-kart or real car tires could see the difference between two foam tires. They'd probably look the same to such a durometer, much like a 1.5 ounce servo would appear to weigh the same as a 1.8 ounce servo on a bathroom scale.

Just my theory...

T
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Old 03-05-2003, 11:40 PM   #13
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That exactly what popsracers said. I've seen this happen on Rockwell hardness testers. Something with hardness in Rockwell A range won't register on a Rockwell B tester it just gives you an error. It's exactly what popsracer said about Shore values. I'm guessing that the foam tires values are in a smaller range and thus requires more resolution and a different scale.
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Old 03-06-2003, 08:59 AM   #14
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Default Why bother if it's not going to be accurate?

Quote:
Originally posted by Trips

Sure it does. I'd be surprised if a durometer for go-kart or real car tires could see the difference between two foam tires. They'd probably look the same to such a durometer, much like a 1.5 ounce servo would appear to weigh the same as a 1.8 ounce servo on a bathroom scale.

Just my theory...

T
This is EXACTLY the Reason, Thank you Trips! (Leon too)
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Old 03-06-2003, 01:46 PM   #15
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i worked with rubber for 12 years
a durometer that dose rubber measures shore a and you need
a different one for shore b wich starts alfter you reach 100
on shore a.
for foam you need a shore f durometer becouse using a shore a
one wont tell you didily
sorry to get technical but it might give people some help on how
it works
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