Just wanted to briefly discuss spring size, since I get questions about this occasionally. The springs used on the Double Barrel (and most other coil over shock springs) is assigned two numbers. For example, 350 x 2.00. The second number refers to the rated “stroke” of the spring, or the “size” of the spring. In the above example, the spring can be safely compressed by at least 2.00 inches. Such a spring will typically be used on a shock with a 2″(50mm) stroke. However, it would work just as well on any shock with less than 2″ of stroke (assuming the overall length would permit it to be installed).

Note that the rated spring stroke is always less than the actual stroke. Why? Consider a 2.00 spring on a 2″ stroke shock with 0.25″ of preload to achieve proper sag. The 0.25″ preload is already in the spring before before any motion of the shock has taken place. Thus, at bottom out of the shock, the spring has compressed 2.25″. Taken to the extreme, if enough preload was put into the spring, the spring could “coil-bind” (”coil-bind” is when a spring’s coils touch each other) before the shock bottomed out. Not good. To prevent coil-bind Cane Creek recommends going up in spring rate or spring size if more than 6mm of preload is necessary to achieve the desired sag setting.

I often get questions on spring rate and would like to clear up a common misconception. On Double Barrel springs (and most other coil springs) the “rate” of the spring is the larger number. On the CCDB the rate is denoted in lbf/in (lbf/in = pounds of force per in). For example, a coil spring marked 350 x 2.00 is 350lbf/in spring). This means it takes 350lb of force to compress the spring every inch. To compress it two inches takes twice as much (700lbf) and so on. The misconception is that preload changes the spring rate, and when I hear this it is like shoving a dagger through my brain’s left lobe (I have been told I have two left lobes… I still don’t know if that is meant as a compliment).

Spring rate is a constant (in theory at least), it does not change (much at all) with preload. To illustrate this, consider a 350lbf/in spring sitting on the ground all by itself. There is no preload on the spring, the spring’s rate is 350lbf/in, and the spring is not at all compressed. Now put a 350lbf weight on top of it. The spring will be compressed 1″, and will have 350lbf of preload on it. Now place an additional 350lbf on it. The spring will now be compressed 2″. The important thing to note is that despite the 350lbf or preload, the spring still moved an additional 1″ when the second 350lbf was added. This means the rate stayed constant, the spring moved 1″ for every 350lbf.

How does this relate to setting your shock up? Well, since spring rate is unaffected by preload, it is not adjustable. Since it isn’t adjustable, getting your spring rate correct is super important, just as important as getting your damper set up correctly (the correct sag can be obtained from any spring rate). Spring rate should be considered an “external adjustment,” just like low & high speed compression and rebound damping (on the CCDB at least!). Changing spring rate does require a new spring, which is why Cane Creek has developed a sophisticaed algorithm to do our best to get you on the right spring the first time.

A few weeks back Josh C. and I headed over to Ohlins to give a Double Barrel a beating on the shaker rig. This is great stuff! You take the info from a data acquisition system mounted on the bike, and download that into a computer. The computer tells the shaker rig to, well, “shake”. So you get to see the Downhill run or runs you did live on the shaker rig. The shaker rig mimics every bump, jump and drift you did on the trail. It’s crazy because you can see your run being played out in front of you. All kinds of hydraulic lines leading to the shaker move around and you watch your Double Barrel getting what you gave it on the trail.

More on the shaker rig…

I get questions on how we use the information we gather from these tests. Here’s the short version: We gather all of a rider’s data from a downhill run and load it into the computer. The computer then tells the shaker to mimic the run on the shock. This gets noisy with all of the hydraulics running the shaker, very fun to watch. I still flinch…. when the shock starts taking big hits. You can also see when a rider slacks off or the trail smoothes out. The short of it is, we can tell if a test rider is using the Double Barrel to it’s full potential.

Heads up,

For all of you in need of a 10” x 3.5” size shock upgrade. “A big ole shock.” We will have the ability to build this length shock sometime in January. I have been on a Session 10 — yes a Session 10 — with this length shock and it completely transforms the bike.