Rate

[400EX QUADER]

what's the difference between double and triple rate for shocks? which are better for trails and dunes?

[cdalejef]

In a nutshell, triple rate has 3 springs and dual rate has 2 springs. Triple rate works better.

[400EX QUADER]

k thanks

[Colby@C&DRacing]

THe more spring rates you have the more progressively you can change them. This makes the transition from soft to stiff much smoother, But some shocks don't have enough body length to do a triple or even a duall rate so you are limited in some cases

[wilkin250r]

The above info is correct, but in order to fully understand "rates" you need to understand springs.

When you push on a spring, it pushes back. Simple, right? It stays nice and simple if you apply even more force. If it takes 40 pounds to compress your spring 1 inch, then 80lbs will compress it 2 inches, and 120lbs will compress it 3 inches. Simple. Linear. Your spring has a "rate" of 40lbs per inch.

Let's say your landing a big jump. Your quad weighs 350, you weigh another 150, but the total force when you land isn't just 500 lbs. You are dealing with MOMENTUM, so its actually equivalent to about 2500 lbs. Let's pretend it's spread equally on all 4 tires, so your front shocks see 625 lbs each. At 8 inches of shock travel, you need a spring rate of almost 80lbs/inch to keep from bottoming out.

Well, that's simple, so what's the problem? The problem is, a 80lbs/inch is REALLY stiff for small bumps and whoops. For small bumps, we only want a spring rate of about 30. But at 30, we can't land big jumps, because the suspension will bottom out way too easy.

So, the compromise is to use multiple springs. You get a small spring with a rate of 30, and then a larger spring with a rate of 80. So on small bumps, you have the nice soft spring rate of 30 to soak them up. When you land a big jump, the 30-rate gets completely compressed, and then the big 80-rate takes over to keep you from bottoming out.

So now you get the picture. Dual-rate uses 2 springs (with two different spring rates), Triple-rate uses 3 springs, ect.

The only thing to keep in mind is this example is REALLY over-simplified. In reality, you have compression damping inside the shock, and you have to use calculus to find the time-derivative of momentum, and integration of total work done by the spring rates, blah blah blah. But now you can grasp the basic concept.