We get many calls asking how much air should be in rear shocks and I bet most other shock makers/distributors get the same questions.

Many people assume that if we know their weight we'll know how much air should be in their shock. Unfortunately that is not really true.

The best place to start is the bike manufacturers recommendations. Even if you have a different shock to what is stock or listed the sag settings are a good place to start.

This mainly applies to air shocks since coil shocks are generally a fully sealed damper only and require workshop servicing. All shocks should be claened after each ride and checked for leaks etc.

Air sleeve service.
This is a much regular maintenance item than most people realise. The air sleeve is part of the shock that holds the air you pump in. To ensure it continues to hold air and move smoothly it needs to be serviced regularly. Most shock manufacturers recommend 25 rding hours. Depending on you riding habits we recommend 3-6 month intervals. This means it should be done at a minimum 2 times a year.

It is not necessary to replace seals at every air sleeve service. Mostly a clean and relube is all that is required.

The negative air spring. When reinstalling the air sleeve you create a negative air spring which is why it is so hard to get it back on. This negative spring is intentional but after a while becomes depleted as air leaks out of the lower seal. One of the most important functions of the air sleeve maintenance is to recharge the negative spring. Keeping your shock clean lubed and with good negative pressure means you have more consistent perfomance from your shock.

NB All new air shocks should have an air sleeve service within 3 months of purchase.
Or ideally at purchase. This is mainly because the period between your bike being built at the factory and you getting on it allows the lubricants to move away from the surfaces they are meant to be on and the negative air spring to become depleted. A quick air sleeve service should have it working exactly like new.

Most shocks use the mounting hardware as shown in the picture below. The shock eye bushing is pressed into the shock eye then the reducers press into the bushing to provide a proper fit into your frame.

Mostly only the bushing needs replacing but if you need replace the reducers you need to know the size of the bolt (usually 6 or 8mm) and the width of the mounting as well as the type of shock the hardware is needed for.

When people talk about DU bushings in mountain bikes they are referring to the shock eye bushing. This is a thin bushing pressed into the 'eye' of the rear shock and into which the frame mountings are fitted. It is there to allow the shock to rotate as required during use.

Shock eye bushings are a wear item, that is ideally they will wear and not the shock or the frame mounting hardware.

DU is the material reference used by the original manufacturer (Garlock) and is a mixture materials including lead. Most shock eye bushings no longer use this material and should be lead free.

	Example of a shock eye bushing in the shock. This one a is a little worn but was not loose.
	This is a new shock eye bushing.