“Vespa ET-4 – How to Replace the Rear Tire”

By Ron Stultz 

5 June 2007

Summary: Not a terrible do-it-yourself (DIY) job but expect to have to use a tire installer to actually get the old tire off the wheel and new tire installed.

Background:

3100 miles on my Vespa ET-4 and the rear Pirelli tire (120/70 – 10) would not pass Virginia safety inspection! 3100 miles! 

How to replace: take to dealer or do it myself? At 3100 miles from a Pirelli, I did not want another Pirelli and was afraid that was what the dealer would install, so I proceeded to replace the rear tire myself. 

What should you do? In the end, I think it probably the easiest to buy the tire you want and then take Vespa and tire to dealer and have them install. Although I got the rear wheel off, I still had to take to a tire specialist to get old tire removed and new installed on the wheel. Suspect I saved some money but not sure how much.

Tools Required: 

If you want to contemplate at least removing the rear wheel yourself, you will need the following tools:

--  6mm Allen wrench ( a 7\32 will also work)

- 10mm socket, ratchet and extension for ratchet

-  24mm socket and at least a 2 foot long ratchet

- A new Cotter pin

- Wheel grease

- A new tire. Suspecting that the tire would not be available locally, I never even checked retail locations but rather searched the Internet. There are several different brands available in the size needed but I chose a Michelin Pilot City as I have had good experiences with Michelin tires. It is interesting to note that no scooter tire from any manufacturer carries a mileage warranty of any type!

To Remove the Rear Tire:

Place the scooter up on the rear stand.

Laying on your back, use a 10mm socket, ratchet and extension to remove the 2 nuts holding the exhaust tube to the frame.  

Now using the 6mm Allen wrench, remove the lower bolt holding the silencer to the frame. When this, longer of the 2 bolts, has been completely removed, remove the upper bolt and when you get near the end of the travel of the bolt, hold the silencer so it does not drop down. Now wiggle the silencer so that the pipe end comes loose from up inside the frame and remove the silencer and set it aside.

With the rear wheel now exposed, remove the Cotter pin on the wheel shaft. Do not reuse this pin when you reinstall the wheel.

Now the hard part. Using a long ratchet and a 24mm socket, place the socket over the wheel nut and while holding the rear brake lever so the rear wheel does not turn, push down on the ratchet. In my case, as the rear wheel had never been removed from the Vespa, I had to actually put my foot on the ratchet and push slowly down until the nut broke loose from the shaft.

Using the 24mm socket and ratchet, remove the wheel nut and the washer that is behind it. If you are lucky, you can now pull off the wheel. I was not lucky. Because the “drum” brakes are behind the wheel, the wheel might not want to come off easily and so use a rubber hammer to gently tap on the wheel or tire as you rotate the tire around. A few times around the wheel and the wheel will begin to move off the shaft.

Once you have the wheel off the shaft, you will see the rear brake shoes and also that the shaft is splined. In my case, there was no grease on the splined shaft at all or on the threads of the shaft where the wheel nut goes.

 With the rear wheel off the Vespa, your best bet is to take the wheel and your new tire to a tire specialist. As the sidewalls of the small Vespa tires are so thick, it is nearly impossible to remove the tire by yourself and don’t even think about a regular service station as they do not have the equipment to deal with the small Vespa tire. In my case, it cost me $12 to have the old tire removed, a new valve stem installed and the new tire mounted at a tire specialty store. Note here that I was told that Sears could deal with this tire but can not confirm as I did not go there.

 With the new tire mounted on the wheel, place some wheel axel grease on the shaft splines and also on the shaft nut threads being careful not to get any on the brake shoes. Now mount the wheel back on the splinted shaft, replace the washer and hand thread on the wheel nut.

 Once the wheel nut is hand tight, using the long ratchet and 24mm socket, hold the rear wheel brake lever and pull upward on the ratchet until the wheel nut is nice and snug. 

Place the nut cover over the nut and use a new Cotter pin to hold it all in place.

Now take the silencer and with the clamp, which holds the pipe end up into the frame and engine, up against the end of the pipe, insert the pipe into the hole in the frame until the pipe engages into the exhaust pipe you can not see. Now hand thread both nuts over the exhaust clamp and then using the 10mm, ratchet and extension to draw the nuts up but not tight yet.

Now use the 6mm Allen wrench and insert the longer of the 2 bolts into the lower hole, bolting the silencer to the frame. Again, tighten up this bolt but not all the way. Now insert the shorter bolt into the upper hole in the silencer and draw it up tight using the Allen wrench. Now tighten the lower bolt. Finally, using the 10mm socket, ratchet and extension, tighten the 2 nuts on the exhaust pipe clamp.

With all tools out of the way, start the scooter and placing a rag over the silencer port, make sure there is no exhaust leak.

All told, it took me about 1 hour to remove and install and another 30 minutes to drive to tire specialist and have tire mounted.