Modern Vespa

How does a windscreen Affect the speed of a Vespa 300GTS?

That really depends on the size of the screen. A mid size screen is the best way to go if this is a concern. They add better aerodynamics than the wind hitting you full on on the chest without the downside off acting like a sail/wall.

TBH not all that much and if it is a concern and you really want a Vespa a Malossi kit will more than make up the loss in speed.

Probably need a wind tunnel to answer that question. Or lots of experimenting on calm days. Aero drag, the normal factor in top speed, is a complex phenomenon, not easily theoretically predictable. Even Formula One teams, with massive computing power and fancy wind tunnels, confirm their experiments on the track.

The prior owner of my SH150i claimed it would go faster with the tall windshield on it than the OEM short one. But he was short, I'm tall, and my head is out in the breeze, regardless.

Having the rider out in the 'wind' creates a lot of drag. Anything that can smoothly direct the airflow around the rider is likely to help.

But mostly windshields are a matter of rider comfort. Not likely to get much more than a couple of MPH from a windshield, if that.

Not that adding any reasonable amount of power is going to change it significantly either.

I put a short Vespa screen on my Primavera. I get +5 mph with it. Its a small scoot that I used to run at WOT all the time. I no longer have to do that. There are definite advantages.

I have a tall wind screen on our GTV300. It makes a difference of 10-12MPG for me.
Living in rural Nebraska, I am usually traveling at highway speeds the majority of my time.
Would love to switch to a smaller screen, but the bugs & wind demand priority 😂

I use one of those on my LX 50 in the summer. Now i have a mid-size Faco. The increase with the flyscreen is truely noticeable.

I have the genuine Vespa mid size screen. I can say with confidence that for me it makes a difference in top speed of 3-4mph. When I serviced the bike earlier this year I had to take off the screen to do some stuff. I tested the bike without the screen and it definitely wasn't as fast when I tried to hit top speed managing 77mph in fairly neutral conditions on the flat. Yet with the screen on an hour later it hit a genuine 80-81mph. It was also a more comfortable ride with most of the wind not hitting my chest.

I have a the Cupini mid size and yeah that's about bang on for and unmodified pre HPE engine.

Clearly there is a scientific answer to this question. As a practical matter I don't notice any difference at all in terms of general operating speed. It might make a difference at the top end but does a couple mph really matter when you are traveling 80+ mph?
JEB

hi there i have a 300 and i have both the smallest size and the tall OEM. small size is great for summer, at high speeds you only get full on wind from high chest up. and i just put on the tall OEM cause winter is here and there is zero wind now. ive taken it on highway and i wont go on highway without it again. no wind travelling at 120km on vespa.... dude. thats the life

edit: zero affect on speed

Is this the one that help the LX50 get a couple more MPH?

https://www.scooterwest.com/vespa-euro-sport-style-flyscreen-lx50-150-lx30pa-sm.html

I could use a little help when I'm pointed into the wind but how small of a screen can I use and see an improvement?

I dunno... I have a good sized screen on this bike and the it doesn't seem to mind whether I have the screen up or down. 120kmh with an on the fly adjustable screen is nice as well. The coffee cup holder on my Vespa however is much better.

I have the midsized Vespa windscreen. Works great for me.

I am not as concerned about top in speed. Without the windshield, my
body acted like a sail and made long range riding tiring on the arms.

Bob Copeland

I haven't warmed up to the looks of the taller screens but I was really surprised when I read that someone picked up some air efficiency on the LX 50! I only have about 120 miles that I put on but it performs to my expectations except when i am facing strong winds such as our trade winds at 25-30mph we have been having. If I can maintain a 3-4 mph bump increase I would probably pony up for one.

I have the mid size genuine vespa screen. End result - more comfortable at speed.

Yeah the mid size seems to be the best all-rounder. I have the Cupini as I don't think there is a mid OEM for the GTV.

I was obviously joking about a windshield slowing down my K1600 but I've had a few BMW's with the adjustable screen and it is an awesome feature.

so I have a full size OEM Vespa windshield on my 300 super. I have had it up to 65mph, which is likely the fastest I would ever want to go on my Vespa and have had no issues, and was certainly not full throttle. Where I live it is cold in winter and lots of bugs in summer and the screen helps me in both of those and also when it is raining. Just my opinion, the most important thing now is to be safe.

larry

I have the mid-size Faco on my GTS, along with a Laminar Lip. I test rode this scoot without a windshield, and it was better without a shield than the stock shield on a BV350, as far as wind blast and helmet noise. With the Faco and the Laminar Lip, I have no idea on any difference in top speed, but the riding experience is more pleasant and quieter.

I have read that the mid-height windshield may add a couple MPH on the top end, but even if it was slower, I'd still be wanting this windshield. Bob's right: the Vespa has some lovely curves... my arms and shoulders were like a drag chute without the windshield. I can ride all day without feeling fatigued.

I have the Faco Twin Screen, and it had proven to be a good choice for me.

I'm hitting the rev limiter at 74mph on my GTS. I'd love to see 80 on the GPS, but there are other factors limiting me and the scoot (rider weight and topcase).

I have the mid-size Vespa screen on my GTS300. I fit it during winter for the cold, and take it off in the spring. I prefer the feel of the wind (which is why I ride a bike instead of driving a car), and I get less wind noise around my helmet without the screen. I haven't been able to detect any difference in top speed - it's 120 km/h on the speedo under neutral conditions, with or without the screen. On a looonngg straight I once hit 125, but can't remember whether I had the screen on that time.

Even before I got hold of Melody, I was certain I'd put a windscreen of some sort on her. Between the minimal initial research I'd done, just-before and after purchasing the bike, I zeroed-in on my requirements:

- Comfort: Reduced wind-pressure to the upper-body. But since I wear nothing but FF helmets, what happens above the neckline is of little importance.

- Performance: The smallest windscreens offer the most in terms of added top-end, in the vicinity of 3mph or so.

These criteria appear to have been nicely borne out with the addition of Vespa's on "Euro-spec" Flyscreen to Melody a few years back. One other perk seems to have come about, at least anecdotally: Stabilty. Maybe it's just me, but I can all but swear that the bike feels just a bit more stable in crosswinds than before the screen was installed; Some recent Autumnal runs across the Verazzano Bridge (upper level, in November, no less) have been all sub-white-knuckle-inducing in relatively high wind conditions, which is about as heavy a test as I can can come up with so far. I'd rather be with that screen than without, all year 'round.