Motorcycle Tech: Honda CB550 Rear Shock Upgrade

Motorcycle Tech: Honda CB550 Rear Shock Upgrade

A huge suspension improvement with little cost

Back in 2011, I bought a 1978 CB550 to ride on the inaugural two-day Kickstart Classic event. The official ride started at Dale’s Wheels Through Time in Maggie Valley, North Carolina, and finished at the Barber Motorsports Park in Birmingham, Alabama. This event was hosted by American Iron Magazine but open to all makes and models, so the American kickers welcomed my Honda.

This event is organized for any bike with a manual kickstart, although the lazy electric-start bikes are also welcome. In the time leading up to the event, I didn’t own a kicker, so I picked up a vintage Honda from eBay. I was told it was a gem and ran great. However, the seller’s idea of “runs great” and mine varied a bit.

I had three months to prepare the bike for long-distance travel. Steve Lita, then editor of AIM and GB, and I decided that we’d ride from AIM’s headquarters in Stamford, Connecticut, to Alabama and back—all or bust.

Over those three months, I went over as many of the mechanics as I could, while bobbing and chopping the bike up into a tight little café: Clubman bars, as cool as they look, were a bad choice. That decision bit me in the lower back two hours into our six-day journey south. I had also overlooked making any upgrades to the suspension, which really should have been addressed. Live and learn.

To make a very long and backbreaking story short, the little Honda and I made it to Alabama, but the engine gave all it could on the ride down. We both rode home in a pickup truck.

It’s taken a while, but I’m resurrecting the old CB from a corner of the shop where it’s sat since 2011. I’m starting with a two-part install of Progressive rear shocks and fork springs. This is part one, the installation of Progressive 12 Series shocks and springs, a comprehensive shock and spring set that includes all the necessary hardware that you’ll need to fit a variety of bikes.

14mm ratchet/torque
Shock spring compressor
Flathead screwdriver
Blue Locktite

Progressive Suspension
12 Series shocks
12 Series springs

Honda CB550 Rear Shock Upgrade
A look at the Progressive Suspension 12 series shocks and springs before assembly.
Honda CB550 Rear Shock Upgrade
Here are the original 1978 shocks.
Honda CB550 Rear Shock Upgrade
Prop up the rear tire to allow for adjustment when fitting the new shocks.
Honda CB550 Rear Shock Upgrade
Remove the old shocks using a 14mm socket or impact driver and save original hardware. Penetrating oil may be needed to loosen the nuts and bolts.
Honda CB550 Rear Shock Upgrade
The bump rubber and washer may need to be lubed in order to move down the piston shaft, making room for the spring assembly.
Honda CB550 Rear Shock Upgrade
A flathead screwdriver assists in moving the bump rubber and washer.
Honda CB550 Rear Shock Upgrade
Install one new shock without the spring and check the clearance between the tire and fender by raising the rear wheel until the shock bottoms. There should be a minimum of 1″ of clearance.
Honda CB550 Rear Shock Upgrade
Assemble the springs onto the shocks using a spring compression tool. This tool will be needed and many options are available for a variety of spring and shock sizes. For this installation, we used a simple lever compression tool.
Honda CB550 Rear Shock Upgrade
A look at the fully assembled shock with the spring retainer clip and top cap in place.
Honda CB550 Rear Shock Upgrade
Supplied spacers were needed for this install when hanging the new shocks.
Honda CB550 Rear Shock Upgrade
Install the new, fully assembled shocks using the original nuts and bolts, lock washers, and provided washers. A little blue Loctite can be applied to the bolts.
Honda CB550 Rear Shock Upgrade
Here’s a look at the new shocks installed and standing proud. RC





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