How to... replace twin rear shocks

WHETHER your old shocks have given up the ghost and failed an MOT, or you want to upgrade to something more fancy, swapping out the shocks on a twin-shock bike is a fairly easy job. Here's how to do it in five easy steps…

1: Preparation

You'll need to get the bike's weight off the rear end, so the shocks are totally uncompressed before you remove them. If you have a centre-stand, you're laughing: get the bike up on there and you're ready to start.

If you don't have a centre stand, you'll need to get the bike lifted up some other way. Use a trolley jack with a piece of wood to take the weight off, hoist it up with a block and tackle from the roof of your garage, or get hold of an Abba stand or similar, which lifts the bike at the swingarm pivot.

The shock mounting bolts might be quite tight, and there's often a chance they're seized in place. Give them a good old squirt with a penetrating lubricant before you start. While that soaks in, go and find the torque settings for the mount bolts, and dig out your torque wrench, breaker bar, and the correct sockets.

A gentle tap on a bolt with a hammer can sometimes be a good way to let corroded threads know you're coming, as it were. It gives them a jolt and increases the chances of the bolt turning when you begin your attack. Do the tapping via a socket and extension bar to avoid hitting anything you don't want to. 

You can make life easier for yourself here: do one side at a time, so the rear end isn't left totally unsupported and doesn't fall down. Unbolt the top and bottom mounting nuts and/or bolts from the first shock, and the shock should pull off fairly easily. You might need to take a little bit of the weight of the swingarm and rear wheel, just to remove any drag on the mount. You can carefully lever it off a bit with a big screwdriver or similar behind the mounts, if there's been any corrosion inside the mount eyes.

Before fitting the new shock, make sure the mount points are all in clean and in good order: no cracks, damaged threads or bad corrosion. Do the same for the mounting nuts and bolts. You can also take the opportunity to give the area behind the shock a good old clean.

This mount has been cleaned and blasted for powder coating, so is pretty clean, but there's some protecting tape still in place that needs to be properly removed. Give the mount a nice coat of copper grease (or your preferred chassis grease), and slide the shock into place, wiggling the swingarm up and down if needed. Refit the nuts and/or bolts, replacing any single-use locking nuts, and torque them up to the correct setting.

Repeat, as they say, on the other side. Once both shocks are fitted, give everything a good wipe down, and consider using some sort of corrosion protection on the new units.

Now, get out there and enjoy all that fancy new damping you've been missing!