Vespa P-Series Steering Locks

One thing that always seem to get lost on scooters that have been sitting for a while are the keys. This section shows how to replace the steering lock on a most 70's-80's Vespa large frame bikes and will soon show how to drop the forks to replace the lock on 60's large frame type scooters, and take apart a Lambretta headset to replace the steering lock. The large frame instructions should also be similar to replacing a small frame lock.

To replace a large frame steering lock you'll need:

An electric drill
1/4 or 3/8" bit (must be sharp)
1/8" drill bit
A flathead screwdriver
Finish hammer and a small punch
New lock and cap rivets (available at scooter shops see differences below).
Pliers
Be sure that you get a new lock that is the same as the one you are removing. There are two types of steering locks that look almost identical except for the flange on the top. All P series bikes use the 4mm lock shown on the right down below (after I drilled out the pins). On the left is a 6mm lock that I believe is used in Rallies and other large frame pre-p-series bikes. Be sure you get the right lock for your bike.



The first thing to do is chuck up the 3/8" bit and drill directly into the brass body of the existing lock. Take it slowly and only drill about 3/4" into the lock. What you are trying to do is destroy the small wafers that make the lock work so that it will turn with a flathead screwdriver



The next step is to drill out the small rivets that hold the metal cap to the frame. Use the 1/8" drill bit and try to remove only the head of the rivet. Using a center punch is very useful to keep the drill bit in place when you start. Once these are removed the cap should come off. Once the wafers are destroyed you should be able to turn the lock about a 1/4 turn anti-clockwise.



Now the old lock can be removed from the bike. Once it is turned the entire lock and a small spring can be pulled from the scooter body. The rivet ends will be sticking out of the body and can be removed with pliers.



Clean the inside of the body area for the new lock. A blast of WD40 always works well. Make sure the little holes for the new rivets are clean



New locks can be bought at any scooter shop. I got mine at First Kick and it also came with a replacement spring that should be fitted as shown. Insert the new key into the lock and then the lock into the scooter body. Test the new lock to be sure it is functioning. When it is in the body in the unlocked position the brass body should stick out of the frame by about 1/4". To lock it, turn the headset all the way to the left, turn the key a quarter turn anti-clockwise, and push the entire lock body into the frame. It may not go immediately so as you are pushing the lock body, slowly turn the headset to the right and the lock will drop into a slot in the forks. Once the lock moves in, turn the key clockwise a quarter turn and the lock should remain in place when the key is removed. If all is well you can move on to refitting the metal cap and rivets. The rivets are threaded and just need to be hammered into place. Fit the cap and both rivets as shown below, and using a finish hammer (not a framing hammer with a waffled head) tap them until they are close to being flush with the cap.



At this point you'll need a small punch to hammer them past the face of the cap until everything is tight. If all goes well you are done and ready to go.

Article : Scooterhelp.com

Posted in: restorations