Motorcycle Shock Spring Preload Adjuster Bottom

Motorbikes change weight more than cars - an empty sedan versus one full of people & cargo might be say 25% heavier - but a naked bike and one with a heavy rider & riding gear plus full tank of fuel might double in weight. So your car manufacturer can use ballpark assumptions and get away with basic non-adjustable coilovers, but your factory motorcycle dampers need more sophistication. If you have damping adjusters read our suspension setup tips to get the most out of them - but even if you don't have clickers read the section on sag because your OEM rear shock absorber will still have spring preload adjustability.

The most common solution for changing the pressure on the shock coil spring is a pair of large locking nuts which screw up and down the threaded damper body. You rotate the big rings using the castellated steps on the outside and a special hooked spanner to increase or decrease the preload.

If you have pre-loaded the spring as much as you can, and you still have too much rider sag, it's time to get a stiffer spring rate. If you've removed all pre-load off the spring, and you don't have enough rider sag, it's time to get a softer spring rate. Read more about suspension spring choice for finer details and expert tips - then see our Shock Springs & Hardware Category to find your new rate and the collars that sit against the preload nut.

These are the lower rings - they set the preload height and are locked in place by the upper ring. If you rarely need to change your preload adjustment standard sets are great, but if you find you can't swing a preload spanner inside that tight trellis frame consider a mechanical preload adjuster - they fit to shock bodies like a regular preload nut but change thickness using a regular socket (on an extension if you want - for hard to reach places). If you're riding with a pillion passenger, multiple terrains or big changes in luggage, you should think about a hydraulic preload adjuster instead - it does the same thing as a mechanical one, but with a simple to use knob and no tools by the side of the road.