Modifying my 1980 Vespa Piaggio Grande

Any way to modify my bike so that it classifies as a motorized bicycle and not a moped? Right now it goes up to 25mph... but it like to limit it to 20. Any ideas?

Re: Modifying my 1980 Vespa Piaggio Grande

This is the bike.

7C48636B-0418-43CF-859F-4F990B6046F4.jpeg

Re: Modifying my 1980 Vespa Piaggio Grande

I don't wanna sound ignorant , but just back off the throttle.

Re: Modifying my 1980 Vespa Piaggio Grande

just look in the wiki on how to register your moped/motor driven cycle.

Re: Modifying my 1980 Vespa Piaggio Grande

Bad Cadillac™ /

Don't do it...

The 5 MPH you want to take off, you'll need for hills and inclines. I'd just leave it and throttle back when you want to. Grande speedos are usually off anyway indicating more.(edited)

Re: Modifying my 1980 Vespa Piaggio Grande

Alexandro Ramirez-Nagy /

1. sick grande, I love them.

2. ditto on the keep the speed, you'll need it for that heavy of a moped.

3. kudos for getting to mopeds, but also, be ready for the italians to haunt you.

Re: Modifying my 1980 Vespa Piaggio Grande

All great points. I just realized that I wasn’t really specific about what I’m trying to accomplish. The main thing that I’m concerned about is the laws here in CA. I want this classified as a Motorized Bicycle. I think it’s 604(b)... the requirements are; a bike with an 50cc or smaller engine, traveling at under 20mph when motorized. This way I can ride it on bike paths, I don’t need an m1 or m2 license, etc.(edited)

Re: Modifying my 1980 Vespa Piaggio Grande

You could use a higher ratio set of transmission gears, or get 100 mm clutch cheeks, or run really light weights in the variator so it won’t variate all the way.

Re: Modifying my 1980 Vespa Piaggio Grande

Bad Cadillac™ /

There were 30, 35 and 30 MPH versions of the Grande made.

The difference between them was a size of the carb and the inner diameters of the exhaust pipes, variator and rear gearing. For example, the largest carb was a 13 mm for the 30 MPH bikes.

You'd need to make it a 20 MPH bike, the parts have part numbers on them i.e. a 7 mm carb is the 20 MPH version.

When a Grande was new, under the right side, side cover was a 20, 25 or 30 black and white sticker, this told you what MPH version it was.

If you wanted to go this route, gathering up all the 20 MPH parts to covert it, after you'd be done, it'd be a true 20 MPH bike for sure!

See this link at Myrons for the specifics on what I just typed! Scroll down until you see "Speed Versions:" and look at the speed info version attachment.

http://www.myronsmopeds.com/category/parts/vespa-parts/(edited)

Re: Modifying my 1980 Vespa Piaggio Grande

Bad Cadillac™ /

Opps my typo above in the first sentence, I meant "20, 25 and 30 MPH versions."

Hit the 3 key instead of the 2! : )(edited)

Re: Modifying my 1980 Vespa Piaggio Grande

It should cost you almost nothing to gather 20 mph parts since everyone takes them off to go faster anyways. Find someone else with a slow grande and trade them, I'm sure they'd be happy to get a few extra mph for free

Re: Modifying my 1980 Vespa Piaggio Grande

Are you trying to make it like a bicycle with a clip on engine, not sure if you can as it has a vin, I will say this is the first time I have ever seen anyone trying to make their bike slower...lol.

Re: Modifying my 1980 Vespa Piaggio Grande

Yes, I’m an odd one. =P My school is a lot stricter than most about certain things, because it’s owned by the federal government. I don’t know either. I think at the DMV, they test it. ...but idk.

Re: Modifying my 1980 Vespa Piaggio Grande

Yea, Bad Cadillac... this would be the solution. I’ve never worked on a bike before, is this a fairly easy swap?(edited)

Re: Modifying my 1980 Vespa Piaggio Grande

Just buy yourself an e-bike, or get the licence, if you do the swap save the old parts, it will make it a lot easier to sell.

Re: Modifying my 1980 Vespa Piaggio Grande

Bad Cadillac™ /

> Michael D'Amour Wrote:

> -------------------------------------------------------

> Yea, Bad Cadillac... this would be the solution. I’ve never worked on a

> bike before, is this a fairly easy swap?

It is really and since Grande has the large grey plastic cover on top, accessing the carb is easy on it.

The exhaust is easily changed out too.

The smaller carb is the key part you'd need when limiting the bike to the speed you want. Exhaust would be second.

I wouldn't worry about the gearing.

As Nick above mentioned, these parts are pretty much always taken off on these bikes in favor of larger replacement parts. If you were to post in the for sale section, I'm sure you'd get someone to say they had the parts.

Ideally you want a working carb, otherwise, you'll have to replace the seals and gaskets so it won't have any kind of leak. Meaning, good intake seal and good bowl and banjo gaskets.

The exhaust can be bolted on and go! Biggest thing it would need it probably to be cleaned up.

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