How-to: Shock replacement

Sooner or later, you'll want to remove your sportbike's stock shock--maybe to replace it with an often superior aftermarket item or to send it to a tuner for a rebuild and revalve job. Either way, you've got to get it off the bike without incident.

You'll need to support the bike with great care. Bikes with centerstands make this task much easier, of course, but other models can be secured by running tie-down straps from the handlebars down to a neat hydraulic lift or, perhaps, to hooks mounted in the garage wall. (Renters, don't use the dining-room wall unless you're a plasterer by trade.) You'll need to lift the rear tire clear of the ground plus another three or four inches, and the whole bike needs to be quite stable as you'll be really rummaging around in there. An ordinary bottle jack will do the deed to lift the rear of the bike once the front is tied down.

On most bikes, the shock will be coming out the bottom so get familiar with the linkage 1. that connects the lower mount of the shock to the rest of the suspension. Because the large aluminum link will be in the way of the shock on its way out, you'll have to disconnect the "dog bones" to make room.

First, though, remove the shock's lower mount bolt 2. and be prepared to work at it. Most of these nuts will be torqued to 50 foot-pounds or more, so have a breaker bar or burly buddy standing by. Be aware that some shock mounts penetrate the frame or shock clevis into threads, while others (like the shock on the Kawasaki ZX-6 shown here) are free-floating with a locking nut on the end. Support the rear wheel while you remove the lower shock bolt.

Break free the forward linkage bolt and carefully extract it 3. Most bikes have simple plain bushings between the bolt and the aluminum link, but a few have needle bearings and you don't want them to fall out and go missing. Move to the upper shock mount 4. and remove the nut and bolt. Before you extract the bolt fully, reach under the bike and support the shock, as it's now free to plummet to the shag carpet. Carefully guide the shock out of the cavity 5.

If you're replacing the shock with an aftermarket item, it's worth a few moments to do your setup before you bury your new purchase in the bike. Set the spring preload to the recommended setting and, if so equipped, set the shock's ride-height adjuster to reproduce the stock shock's free length 6.

Odds are good your replacement shock will have a remote reservoir where the stock item did not. Use care in placing the reservoir to keep it reasonably cool and accessible for compression-damping adjustments 7. Most aftermarket shocks will come with recommendations for mounting.

Route the reservoir up through the frame ahead of the shock so the line exits where you need it to 8. This may require removal of additional parts and you should take the time to do it right rather than jam a 30mm reservoir through a 28mm hole. Once the shock is oriented in the frame, replace the top bolt and check for clearance around the reservoir line 9.

You may need to twist the shock's lower mount at the clevis to align it with the linkage; do it now, while you have the room. A screwdriver stuck through the clevis will do the trick. Reassemble the linkage and lower mount 10. with a thin layer of grease on the bushing and bolts. (You may use the grease gun if your bike has Zerk fittings like this Kawasaki.) Torque the bolts to spec, usually 57 foot-pounds for 10mm bolts on the linkage and 36 foot-pounds for the 8mm bolts often used on the shock clevis itself. Secure the remote reservoir and you're done.

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