Barrel vs Linear Springs
Today we are going to talk about the two most common types of springs found on coilovers - linear and barrel. Each of these has their own advantages, and drawbacks.
- Usually cheaper than a barrel spring
- Easier to fit with high offset wheels
- Higher block height than a barrel
- Sometimes weighs more than a barrel
- Shorter length springs can be used
- More travel compared to an equal length linear spring
- Lighter than a linear
- Limited rates (most only go to 350lbs)
- Wide center can have clearance issues
- Almost double the price of a linear in equal configuration
Lets compare a 12 inch, 200lb Eibach linear (250) vs a 12" 200lb Eibach Barrel (2530) spring..
Block Height: 4.07"
Total Travel: 7.93"
Block Height: 3.28"
Total Travel: 8.72"
*Different manufacturers may have different weights
**Block height is the length of the spring at full compression
As you can see, the barrel spring has a travel advantage of .79" before it is fully compressed. As you go higher in length, the separation of travel between linear and barrel increases exponentially. As you increase spring rates (350lb for instance), the barrel gains even more advantage over the linear due to the thicker coils on a linear spring. A 350lb 2530barrel spring has a 1.11" travel advantage over the 250 linear. That's significant. The barrel also weighs about 4oz lighter at the 350lb rate.
While none of those above listed numbers seem mind-blowing, I can tell you one extreme advantage the barrel has over linear...that's in divorced rear suspension designs (where the shock and spring are separated). It's not overly obvious in the picture above, but there is a significant curvature of the spring. When the corner is off the ground, the curve is much more pronounced.
Using a linear spring, this angle generally causes the end of the spring to unseat on a corner. It's not a huge issue, but with the barrel maintaining a constant contact point all-around, that is an advantage. It also makes it easier to install as the spring works with you instead of against you.
Lastly, the main thing I like about barrels, is deflection resistance. Springs aren't perfect. Its metal, there are variances. In some cases, the flat end of a spring is clocked differently on each end, which causes a point of favoritism in the material. A slight variance will create a weak point at the opposite end. That weak point usually goes to the center of the spring body.
When that happens, the springs center will lean in or out (depending on the side). The side leaning in is likely to hit the shock body. I should mention, this is most obvious on long low rate springs - like a 14" 200lb spring. A barrel spring will never have this issue...it may deflect but the center is the widest part of the spring, so it can not deflect enough to make contact with the shock body.
I like barrels, but they're not needed in every suspension, and we tend to mix-and-match the springs depending on the application. A Subaru Outback does great with a barrel front/ linear rear. A Bronco Sport uses barrels on all 4.
So, in all of this...one is not better than the other when sitting on a shelf (we can put more linear springs on a shelf, win), but one certainly is better depending on the application.