Tires - Fixing a Flat
Fixing a flat on a scooter is an easy project. The design of both wheels on a Vespas and the rear wheel on a Lambretta makes it very easy to remove the tire and rim to change it. On a Vespa both wheels are single sided meaning the forks or engine is on one side and the other side is free. On a Lambretta the rear tire is single sided but the front has fork connections on either side - click for a link to the Lambretta front tire change page. Also both scooters halve split rims which allows you to get access to the tube without having to get the tire off the rim like a car.
Tools - You will need:
The first step is to remove the wheel and rim from the hub. The pictures below show this being done on the front wheel of a pre P-range Vespa. To remove the front wheel find the five wheel nuts on the hub side of the wheel and remove them. The tire sometimes takes a little wiggling to get it clear of the body work.
Once the wheel is removed remove any extra air from the tube by pressing in the small needle at the center of the air valve stem.
Flip the tire over and remove the five 13mm nuts which hold the two steel rims together. Be aware that the two halves are different widths and the wheel must go back on the bike in the same direction. The final step in this guide shows the correct wheel/rim/hub installation.
Usually the tire will have a very strong grip on either side on the wheel rim halves. There is no need to remove the tire from the rim as the rims can be separated with spacer to allow removal of the old tube. I use deep sockets as shown in the image below but anything would do.
Remove the old tube by pulling it out. You can patch the existing tube but I usually use a new tube. To find a leak in an old tube, inflate it slightly and put it in the kitchen sink. Rotate the tube so that every part of it goes underwater. The leak will be evident by bubbles in the water and it can then be patched.
Before reinstalling the tube, carefully run your hand around the inside face of the tire to make sure that whatever gave you the leak in the first place is not still lodged in the tire. Sometimes glass or a nail can remain punched through the tire and do the same thing to the new tube.
The valve stem is the best place to start feeding in the new tube. It is helpful to put a bit of air in the tube prior to this because it is more easy to handle. The valve stem needs to be pushed through the wider side of the rim so that the valve head protrudes on the thin side of the two rim halves.
Carefully close the two rim halves and be sure not to pinch the inner tube. Tighten the five nuts to secure the two rim halves. Inflate the tire to 18 PSI for the front or 25 - 35 PSI for the back. If you regularly ride with two people use the higher number.
Below is a shot of the correct way a Vespa rim should be mounted to be sure the wheel will be centered properly. If it reversed the wheel will not fall on the centerline of the bike.
Replace the wheel and you are good to go....