Sulastic Springs

carringb wrote:
Yup. Works as advertised. Just beware they are designed to reduce harshness. They are not intended to make the springs rate softer and more plush.

I am due for a new set, after ~8 years. Just like rubber torsion axles, the load bearing material eventually fatigues. It can't come apart, but they end up just sitting on the travel stop and act like a regular shackle. I do plan on emailing them to see if they'll warranty it.

As a side benefit, they are much stronger than the OEM shackles. Some of heavy camper vans eventually tear up the stock shackles. The Sulastics have about 5x the steel mass of the stock shackles.