Hi All
I am wondering if anyone knows an approximate spring rate for the Minispares road rally rubber cones. I would think it would not be consistent as it compresses but I am just after a guide.
Regards
Adam

Here you go, I found this on the web a while back so saved a copy.

would have thought they both would be less linear than they appear. Any ideas on how that was tested (it could make a huge difference)?

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Well going by the chart it looks like it was done in a lab just using measurable weight/pressure id guess as looking at the chart it took approximately 110kg to compress the normal rubber cone 10mm and the red dot cone took approximately 210kg to compress that 10mm " if that makes sense " .

Probably would have been better to measure the cones going over a corrigated road as it would show the compression/travel difference between to the 2 cones in a step looking graph.

Cheers Bill

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I agree, way too linear for rubber compression...

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The right way would be to have the rubber spring mounted on the trumpet or a hi-lo that it is being used with. That way the natural non-linear rate and hysteresis of the rubber will be properly combined with the curved mating face that produces it's own non-linear effect on the rate. Also need to have it pass through the normal loaded weight for each corner, which that graph does - but the scaling is all wrong because a single cone will only ever see a 900kg load if the entire weight of the car, plus passengers and luggage was on one wheel. That is a rare occurance - no race car will be fully loaded up to 900kg and road cars loaded this way probably should not be driven in such a way to generate that situation! Also they are mixing their terms - Pressure is kg/m^2, they could also mean that horrible term kg force (which is meant to be the mass multiplied by acceleration, usually gravity), mass is kg - what do they really mean?

Like i said it makes a huge difference to interpreting the graph.

cheers
michael

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Thank you mini13 I appreciate the information. Any ideas on where you found it on the net and if there is anymore info there.

Hi Adam
This is how the test was done
http://www.mokesinc.org/index.php/topic ... #msg119700

kjn

Interesting Ken. That answers all of my questions and Spider tested exactly the way i said.

I do note that the graph in that moke thread is a lot less linear than the one that appears above.

Spider also questioned the spring rates quoted on the Mini Spares website. That one is easy - they are quoting wheel rates, which vary depending on the exact geometry, not the linear rates which he was testing.

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Hi Ken
Did you see with the above graph if it was preloaded. Ie in my car would I be looking at 21mm or 30mm approx. I couldn't see the above graph on the link. I would say that my small diameter Hilos would be similar to the standard trumpet diameter.

it is not just the diameter, but the shape as well.

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66 Mini Minor sponsored by http://www.lifeonthehedge.com.au/ The Dog Harness Specialists
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I think you're confusing static weight with a dynamic loading. The loading on an individual spring at the bottom of it's travel coming out of a pothole is going to be well in excess of a quarter of the car's weight. I have no idea whatsoever of the loading one corner might see in normal use, but it won't be close to 1/4 the weight.

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Ah thanks Spider, I got the info from the link below which only has the graph, good to see the extra stuff in the thread.

http://mk1-forum.net/viewtopic.php?f=3& ... one#p58977

Smac,

with the dynamic loading ie Pothole incident, the shock will be taking a large amount of this weight,