Rear Shock Spring Inner Diameters

The inner diameter of a coil spring determines a coil's compatibility with coil shocks, and this page will help you figure out exactly which coil springs are compatible with your coil shock. The measurements listed here are the inner diameter of the coil spring and the outer diameter of the spring mounting perches for shocks of each brand. For example, Fox springs have a 1.385" ID, which means Fox shocks have a 1.385" OD spring perch.

Unfortunately spring manufacturers have not settled on a universal standard inner diameter, and there are tons of different number flying around here. To find a spring that works with your shock, your safest option is using a spring with the same ID that your shock manufacturer uses. So if you have a RockShox Super Deluxe Coil, then you can use either a RockShox spring or an MRP Progressive spring, because they are both 1.5" ID.

There is a little bit of flexibility, and you can fit a spring with a larger ID than your shock's OD as long as you use an adapter. MRP and Cane Creek make some adapters, but buying a spring that fits your shock exactly is your safest option. Some springs like Sprindex will include spacers to fit most shocks.

1 All Sprindex springs ship with adapters to fit RockShox, Fox, Cane Creek, DVO, and X-Fusion shocks
2 Super Alloy Racing springs purchased through their website will include adapters to fit any shock.