Let me start off by saying I’ve never been unhappy with my Rock Krawler springs. They seem to make a pretty good product. However, that being said, I don’t think they were the right purchase for me.
Our test vehicle is a 2012 Jeep Wrangler JK Unlimited. We have a fairly light weight steel bumper that weighs around 60lbs along with a synthetic winch. There is a fairly heavy Gobi roof rack and ace engineering rock sliders. The rear bumper is stock.
I was looking for the softest ride possible, I basically did not want to be able to feel a thing while driving down the road. I paired these with Rancho 9000XL shocks after reading outstanding reviews from Four Wheeler Magazine.
The Rock Krawler coils are the updated triple rate springs. Coming from the car scene, it seemed crazy going from a “progressive” coil to a linear coil. But the more I thought about it, it kinda made sense going to linear. (I’ll explain later)
After installing the EVO coils, the height increase was very noticeable. The EVO coils were almost 2″ higher in the front and 1.5″ higher in the rear. Mind you the springs will probably settle at least half an inch. The overall length of the uncompressed coils were about the same, which had me worried as this may result in a stiffer ride with a linear spring.
The ride quality with the Rock Krawlers has always been fine. However to get the ride quality I was most happy with, I had to set my Rancho Shocks to 1 out of 9 – 1 being the softest. Under normal driving circumstances, this was fine. However hitting big bumps, the spring would compress past the soft part of the coils and into the higher rate spring. This would result in the Jeep kicking back abruptly since the shock was tuned only for the soft part of the coil.
Where the Rock Crawler coils shine is on the road and handling. One of my mechanics was surprised as to how well this lifted jeep handled on the road. I think the RK coils need to be paired with a stiffer shock setting so that the rebound control can match the stiffer part of the spring. However this would result in a harsher overall ride. This might be solved with a more expensive bypass shock.
The Plush Coils however did not have this issue. I did notice that with small bumpers, the Plush coils are a tad bit stiffer. The spring rate of the Plush Coils must be just slightly stiffer than the softest part of the Rock Krawler Coils. However, hitting big bumps is where the Plush Coils showed their true potential. There was definitely less shock hitting big pot holes and coming off curbs. Even approaching curbs, I feel like I could hit them at a higher rate of speed.
The big plus side to the Plush Coils is that they seem to match up to the Rancho Shocks very well. The rebound control is much better and there is significantly less kick back and body yaw (side to side bouncing). The obvious downside to these softer coils is the handling. The Jeep definitely rolls more while cornering. But this is a compromise I was willing to accept.
Overall, these coils are better for me, its a softer overall ride. The increased body roll is completely acceptable.
For a better handling ride, definitely go with the Rock Krawlers. If you have the money, fork out the money for a set of bypass shocks, I believe they will go hand in hand with these springs.