Modern Vespa

Anyone done this on a vintage scoot?
I'm keen on getting better handling, disc brakes, better suspension option, better tyres, etc that would in theory come with this, but I'd like to hear from people who have actually done it, or at least ridden a scoot with the conversion.
What potential pitfalls have you encountered? Is handling and/or braking actually better, or for that matter worse?
I'm considering it for a GS160 with a fruity PX engine in it.
Any comments appreciated. Cheers

I haven't done it nor would I. I have however seen it done on a couple of PX's and SIP did it I think on a Sprint demo bike.

It looks bloody stupid to me, like some sort of bad cartoon.


If you like the look and are okay with the cost then fire on by all means but maybe try it on something other than a GS before deciding you must go there.

How much better handling are you after?
How much better disc braking are you after?
How much better suspension are you after?
How much better tires are you after?

Exellent aftermarket parts that will fit a 10" wheel are availble to all of the questions i just put forth. Remember, the rear swingarm will only be able to accommodate only a certain oversizing of tires, and no more. Once you get a tire tall enough, it will rub on the swingarm. I think somewhere around a 1" taller tire than stock will fit? I doubt you'll get better handling with a taller lower profile tire...different handling, probably yes, but better?...it depends upon who you ask. Tires will definitely be more expensive. You'll probably also have to regear the transmission for the oversized tires too. But if you're more after a custom build to your GS, then go for it. SIP also makes 11'' tubless rims that bolt on to a stock hub.

I agree with this. Doing it to a GS160 is lame.

Comments on aesthetics and if you think something is lame or not aren't really helpful, nor are they within the scope of the original post. Luckily there are people in the scene who can live beyond what everyone else thinks, or we might as well all go buy a Kymco in the same colour.

Some people like choppers, some like cutdowns, some like lights and mirrors, some like patina, and some like upsetting the purists by bastardising scooters within an inch of their life. I have two GS160s. I don't want a matching pair that do the same and look the same.

By the way, as far as I've worked out so far the 12" conversion is all reversible so if I did tire of it I can change it. I was simply asking for opinions on the actual effects and outcomes. Thanks whodatschrome for your answer - some useful info there.

There was a chap on here from Singapore called Jakester I think, who has done the 12" conversion on a PX. I realise you are talking about a much older GS, but in principle, both bikes should have similar characteristics. The other benefit (or maybe it's not a benefit) is that you'll see some significant upgearing. What's your engine spec.?

Hopefully he'll spot this and reply. PX with Quattrini M232. Kept conservative with 24/24 carb and SIP Road 2 pipe for a more touring tune. Only just built so running in but by all accounts should have plenty of hp and torque.

You could send him a message - https://modernvespa.com/members/jakester

Are you going to run the 232 as reed or rotary?

Ok, I'll elaborate. The GS160 is quite old (relatively) and has a unique suspension that will most likely not respond well to a 12" wheel conversion. It is also a quite rare model that should not be, in my humble opinion, altered or modified. By doing this, you also reduce the value of the bike. I believe that doing this to a more modern, less rare bike like a PX or a Sprint might be a better idea. In other words, doing this to a PX or a Sprint might not be lame.

I have both a PX150 and a GS160 and each handles very differently. The PX is higher, more upright, quicker, and more nimble. The GS160 is lower, slower, and less responsive. The space within the mudguards is also different. The GS mudguard does not have much open space, whereas the PX does.

These aren't even 12" and look how lame this one is
You sure you are a kiwi and not German Chocolate boy? I'm in Auckland... I totally get where you are coming from. I think the consensus is 12" is for looks only - the $$$ (lots of $$$) is not worth it for any performance characteristics you might get given what can be done to improve 10" setups. But if you want GTS wheels on your vintage ride... it's gonna cost you! The same is said of disc brakes and wide tyre conversions.

Nomad, I totally get that a stock GS and a stock PX will be very different rides. However, by the time the OP has changed the forks and suspension, put a disc brake on, fitted 12" wheels etc., I would have thought they'd be similar. The big thing for me is the engine hanging out on the right, which gives any largeframe Vespa it's main characteristics over a Lambretta, motorcycle or even smallframe.

I probably should have kept quiet as I'm pretty biased in favor of stock nos everything. I will admit that those German hotrods look really dang cool. At least they do it right.

I'm running 12 inch conversion on my PX. The main reason I did it as about 3 years ago a lot of the guys over here in Singapore did the conversion and I was jealous. I used the 2 hubs from SIP but still had to use a couple of shims when mounting my tyres. 12's look pretty cool on the PX and up the gearing a bit but in hindsight I'm not really sure it was worth the cash. If you get a shiny set of tubeless 10's they also look good. You pays your money and takes your chance but I wouldn't do it on a GS

Edit - Maybe its a bit more stable on 12's though I don't really recall as I have been running 12s for like 3 years. I regularly buzz around at 70mph leaving a lot of cars behind me

i like you mate, well i like everyone here as well so here's a inspiration.. dont tell folks i did this


it has the 12 inchi conversion rims by ebeth in the back


its not a gs 160 like ur, its.... what the hell just said its ebeth custum pink vespa


in case u wanna add a disc here's a what maybe look alike, and yes i use a p series engine in there

good luck with the bike and cheer mate

Beautiful!, but if you had a GS, would you do the same to it? 🤗

Where you going with the big engine and the huge wheels?