Reply To: Z750B1 1976

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Next I decided to tackle the rear shocks. These are Marzocchi Strada shocks that were often fitted as standard equipment on Italian bikes of the era. They were sometimes fitted as upgrades so I decided to keep them and do them up. They are rebuildable if the chrome on the shaft is still good but the kit costs £300 and a new set of RFY shocks would cost £65 so I will just replace them if they are in bad condition. I decided to do them one at a time so I can still wheel the bike around as required.

This is as it came off the bike.

It got a good clean and I knocked up a few bits to make a spring compressor.

Next I used a 32mm spanner to remove the nut and get all the guts out. The shaft was ok but the main seal was quite hard. I tried to match up a seal but they use a rotary seal instead of a linear one so I just purchased a pair of seals with the same dimensions. The lip is a bit lower but I think it will work. At this point I tried to remove the cap from the gas cylinder part and it was seized solid. I was using and adjustable pin spanner for an angle grinder which wasn’t working so I decided to make a special socket. I drilled out the holes on the cap a little bigger to repair the damage to them and added another 2 holes to increase the drive surface area.

Here are a few photos of the process of turning an old bolt head into a special socket.

I did the hex in my milling machine and then drilled it for the pins. I had planned to just use super glue to hold in the pins but I decided to leave them loose so I could use the socket as a drill jig to add the extra holes in the other shock.

The hex is 19mm

Here it is with its holes

And with the pins mounted. I machined the pins to a slight dovetail so they bite in under pressure and wont slip out. I managed to mess super glue allover the place but it will all just clean off.

Here it is in use.

The cap was very tight so I used a long bar and a lot of force but eventually it gave up and came loose. You can see the modified cap in this picture. This modification worked very well.

The bladder turned out to be free of leaks and in good condition. Hopefully the other one is the same.

Next the bodies were stripped and painted with more Aldi paint. All the photos I have seen of these are red so that’s what I used. Its not an exact paint match but looks pretty good. The springs were sanded and repainted black and the aluminium parts given a scotch brite treatment. I didn’t strip all the paint off the springs as I know it can be difficult to get the paint even on the inside of the coils and I didn’t want to put it on so thick it would take weeks to dry. I also didn’t like the way the preload adjuster wobbled around on the body and it looked like the spring would be rubbing the body too so I decided to make a spacer to align them. You can see it in the following picture. It adds 4mm to the height so it will result in slightly higher preload but I will assemble these on their lowest setting and see how it goes.

Here is a better picture of the spacer

Next the whole thing was reassembled with new oil and the new main seal. Then the spring compressor was used with a bit of masking tape as protection. You can also see the fresh plating on the drain screw.

And here is the end result. I’m quite happy with it. I still haven’t decided on a colour for this bike. The V5 says green but it should be red which would match these shocks well 🙂

More to follow

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