Meet of the week
What compression, rebound and spring preload mean – and what needs tweaking
Get yourself down to the Ox & Plough
1 Front rebound adjustment
The rebound adjuster controls the speed at which the forks return to the open or extended position. This adjuster is located usually on either end of the forks – on older bikes it is commonly at the top. Turned all the way in, it will slow down the fork’s return; adjusted to the low damping setting, the forks spring back very quickly. Add or remove damping a click or half-a-turn at a time, then fine-tune in smaller increments.
2 Fork preload adjustment
Fork preload is the amount that the front spring is compressed when in its normal resting state. Increasing the preload will reduce the amount that the bike sags on its springs and will give the inpression of the forks feeling harder. Likewise, winding the preload out will make the suspension sit lower in its stroke and the forks appear to feel softer. The adjuster is usually situated on the top of the fork.
3 Front compression adjustment
The speed at which the fork compresses is managed by the compression damping. This adjuster is often found at the bottom of the fork leg, but check in your manual as some bikes have it at the top of the fork leg. With the adjustment fully turned up, the forks will feel hard to compress and at the lower settings the resistance is removed and the forks dive more freely.
4 Fork protrusion
The fork’s protrusion through the top yoke is something a lot of sportsbikes have provision for and allows you to change the ride-height of the front end by sliding the forks through the top yoke. Usually done a few millimetres at a time, and measured with a ruler or digital vernier from the top of the yoke to the top of the fork leg excluding the fork cap.
5 Rear compression adjustment
The rear shock shares the same adjustment functions as the forks. The adjuster for compression damping is usually located at the top of the shock. Changes can be made either with a screwdriver/ Allen key or sometimes a knob. More damping will slow down the shock’s ability to compress quickly, while less will have the opposite effect.
6 Rear rebound adjustment
Usually found right at the bottom of the shock (check your owner’s manual to be sure of its location). Quite often it is necessary to get down on the floor to gain access to it. The adjuster controls the return speed of the shock: with zero damping, the ride will be very bouncy and feel uncontrolled, too much and it will feel hard and choppy.
7 Rear preload adjustment
The rear shock preload adjustment will usually require the use of a C-spanner. Make sure you have good access, loosen the top locking ring and spin it up the shock so you can get good access to the remaining ring. Adjustment is done by turning the ring clockwise to increase the preload strength, and counter to reduce the effect.
8 Measuring your adjustment
When you’re adjusting the rear preload settings you can either count the number of turns you make on the lock rings or measure the amount of threads exposed above it. If you measure the threads you can use either a ruler or tape measure to do this. Make sure that you take your measurements with the locking or top ring in place, both before and after adjustment.
9 Basic set-up assessment
You can assess what your changes have done by pressing down on the front or back of the bike. You can get a feel for the amount of effort needed to push down the bike (compression damping effect) and the speed at which it returns (rebound damping effect). The same thing can be done by pushing the forks down with the handlebars. This will give you a feel for any changes and the range of adjustment.