[P1michaud]

Just currious to know if OME front coils (880, 881 & 882) are progressive? Of all the reading about these, I've never come accross the answer.
Cheers,
P

 

[TacoCrazy]

No they are not...

 

[Bryanccfshr]

Not by definition. Of course spring rate is not linear anyway so as the spring compresses it takes increasingly more force to continue the compression.

 

[22RToy]

Not by definition. Of course spring rate is not linear anyway so as the spring compresses it takes increasingly more force to continue the compression.

As long as the additional force required is directly proportional to the deflection, that is linear. F=kx. Spring rate k is constant.

In a progressive spring, the rate is a function of the deflection, say F=(k+.1x)x. As the deflection increases, the spring rate increases.

Of course, this is all in theory.

 

[Bryanccfshr]

As long as the additional force required is directly proportional to the deflection, that is linear. F=kx. Spring rate k is constant.

In a progressive spring, the rate is a function of the deflection, say F=(k+.1x)x. As the deflection increases, the spring rate increases.

Of course, this is all in theory.

You are correct on the constant
Highlighted is where reality of suspension geometry trumps theory. The spring rate is constant, but the force required goes up due to dynamic angles. Static angles would be ideal in theory but difficult to design and build.

I am bored today at work.

 

[22RToy]

Yeah, theory looks nice on paper, but doesn't reflect reality. Although, the differences are usually negligible.

I'm bored too, except at home. Think I'll go for a bike ride.

 

[P1michaud]

Simple example

Yeah, theory looks nice on paper, but doesn't reflect reality.

You could not have said it any better. I'm an engineer and I can tell you first hand that there can be a huge difference between theory and reality! On the other hand, sometimes you calculate something and it works out perfect. Who knows.

What about an example comparing two spings.
One progressive and the other not. Let's say they are both rated at 500 #/in, both about 14" long. How much of a difference will you feel on your Tacoma (assume V6, extended cab, 4x4, no aftermarket bumper or winch)?
Read comparisson between the OME 881 coils that are 14.4" (365 mm) long, rated at 500 #/in, not progressive vs Tundra TRD not sure about the length, rated at 475#/in (this figure is up for debate) but are progressive.

Assuming they are both of the same lenght, #/in rating the only difference being progressive or not, I would think that the progressive springs would give a much nicer ride.

I just found out that the OME 881 are the same length but different wire diameter than the Tundra TRD, see here http://fastq.com/~sschaefer/front_coil-springs.html

Cheers :xbeer3: ,
P

 

[22RToy]

Assuming they are both of the same lenght, #/in rating the only difference being progressive or not, I would think that the progressive springs would give a much nicer ride.

Ah, but can you safely assume that a linear spring and a progressive spring can have the same spring rate? By definition, I don't think you can. However, I would agree that a progressive spring would feel more comfortable than a linear one. With less weight, the rate is lower, and can soak up little bumps more effectively yet handle larger bumps as the weight increases.

BTW, I'm an engineer too. :xcrazy: