Modern Vespa

Greetings, I am brand new to Vespas since I undertook a 1962 VBB resto project about 2 months ago. I have been making a slow, gradual progress on it since the scooter came with only 50% of parts. For example, for the engine I only had a crank, a engine case, a cush drive, and a severely rusted cylinder. So far I have the engine rebuilt by rebuilding what I had and supplementing what I was missing with parts. I feeling like I am having to learn more than I bargained for out of necessity.

Now, the latest problem. When I try to install the rear hub to the engine by tightening the castle nut, the hub gets pressed against the brake backing plate thereby immobilizing it. In my mind, it would make sense for the hub to be bolted against something that also turns. Any idea what I am doing wrong?

Like I said, I am missing lots of parts and I am having to refer to the parts list as I go along. I am wondering if I am missing something here?

Also, I have new brake shoes to go with the hub but I can't seem to get hub to go over those shoes since the brake lining is too thick. Do I need to trun the inner lining of the hub to make room?

Lastly, I can't see to source that retaining metal clip that holds the two brake shoes to a cam. Where can I get it? Scootermercato is out of stock on it and I can't find it anywhere else.

Thanks for your suggestions!

Min

What is the serial number on your engine? The only time I have had problems with the rear hub locking up on install is when I am putting an 8" hub on a engine with 10" wheels.

As for the retaining clip, are you referring to the wire piece that looks like "Ω"? Just go to the hardware store and get a circlip. Make sure to put a teensy smear of grease on the post.

Good luck with you project!

I don't recall the serial # on the engine, but it is the original 1962 VBB engine with a 8" hub. My wheels are 8" and the hub fits in the wheel. I am trying to understand in priciple how the hum is supposed to turn. The way I have it set up doesn't make sense to me. I am thinking that the hub should be fastened to the drive shaft and to nothing else in order to move.

Yes, I am referring to the omega shaped clip. I did get a circlip from Ace the other day, but I got the wrong size.

Min

there should be a thick spacer washer between the castle nut and the hub?

Yep, I am missing the spacer nut. But again, wouldn't the spacer washer together with the nut just press the enitre hub again the backing plate?

I second this line of thinking, you said you supplemented with bought parts, are you sure the "backing plate" is for 8" and what about the brake shoes? If you didn't tighten the large castle nut behind the plate it could be pushing it out, also if the seal behind the large nut is in backwards or not properly seated. Also check that the brakes are seated on the plunger right and compressed, not raised.

Pics are always helpful.

You are correct. The washer would have to be on the inside to affect the distance between the two parts.

Thank you all for your suggestions. I am attaching the pictures of my hub, backing plate, etc.

I guess my first question is do I have the right hub and the plate?

If so, am I only missing the washer. If so, where exactly would it go?

Thanks.