The Goldilocks Dilemma: Finding the Perfect Scooter Windscreen

As is well-documented on this blog, a few months ago I bought a Piaggio Beverly 350 for use when I'm in Northern Ireland. It was a bit of a project, and one of the first upgrades on my list was the windscreen.

The original screen was fine, but being a bit taller than average, I found that while it took the wind off my chest, it directed a perfect jet of turbulent air straight at my helmet. The result was a huge amount of wind noise and buffeting.

My first attempt at a cheap fix was to try one of those little clip-on windscreen extenders you see all over Amazon. While it did cut down some of the wind, it wasn't a huge improvement. Worse, the distorted plastic edge of the extender sat directly in my line of sight, which was incredibly distracting and far from ideal. It was a failed experiment.

Solution 1: The Full-Height Touring Screen

With the extender failing to solve the problem, I went shopping for a proper replacement. This is Northern Ireland, where winter lasts about nine months of the year, so the obvious choice was a full-height screen that also covers the handgrips. There are a few options out there, but I'm a fan of Givi stuff, so it was an easy choice. I ordered one from Amazon for about £115.

Now, I know these big "sail" screens aren't to everyone's liking, but I loved it. The wind noise and buffeting were completely gone. It was like riding in a bubble of silence. Perfect.

Almost.

The Unexpected Side-Effect: The Megaphone

On my next few longer rides, I noticed I was getting a headache. As soon as I hit 60mph, the noise from the engine seemed incredibly loud. Nothing else on the bike had changed. A quick Google revealed the answer.

Without getting too technical, a large touring screen creates a bubble of still air behind it. At speed, the air rushing over the top and around the sides creates a low-pressure zone, or a 'vortex,' right where your head is. This void desperately wants to be filled, so it sucks in turbulent air from wherever it can, including from below. This effectively funnels the engine's mechanical noise straight up into your helmet, like a giant acoustic megaphone.

So, while the screen didn't make the engine itself louder, it focused all of its sound directly at my ears. As someone with delicate hearing (too many loud clubs in my youth!), this was a real problem. Good quality earplugs didn't help much. I wasn't about to buy another expensive screen, so I figured I had two options: suck it up, or stay below 60mph.

Solution 2: The Vinted Bargain

Then, while browsing the online car boot sale that is Vinted, I spotted a brand new Givi A23 screen. It was bigger than the stock screen, but much smaller than the full-height one. The seller was asking £20 for it. I figured I might be able to adapt it to fit the existing Givi mounting kit, so I took a punt and bought it.

And now, I'm pleased to say, that with a little bit of customisation, it fits. And it's actually perfect!

It provides just the right amount of protection to stop the wind hitting my helmet, but it's not so large that it creates the "megaphone effect." I can ride at speed without being deafened.

The customisation was surprisingly simple. The mounting holes lined up perfectly with the existing Givi kit, so no drilling was needed. All I had to do was take a sander to the bottom edge of the screen to reshape it slightly so it would sit neatly over the headlight. I do still need to tidy up the customisation job, but it's a ten-minute job that might get done soon. Might!

A Screen for All Seasons

So, is the big screen now redundant? Not at all. The new, smaller screen is perfect for most of the year, but it doesn't have the handgrip protection of the full-height one. For the depths of a freezing NI winter, I'll switch back to the big Givi screen. It's a five-minute job, and in the winter I'll be going slower anyway, so the engine noise won't be an issue.

It's the Goldilocks solution: a screen for all seasons.

Update: The Counter-Intuitive Fix for a Loud Touring Screen

After finding my "Goldilocks" solution with the smaller Givi screen, I couldn't stop thinking about the full-height one (the Givi 5606A). The deafening engine noise was its only flaw. Based on the "vortex" theory, I had a thought: what if I deliberately let more air in?

The Givi A5606A mounting kit for the Beverly consists of two "goal posts" that the screen clamps onto, giving you about three inches of vertical adjustment. The obvious, intuitive way to mount it is as low as possible, fitting it snugly around the headlight and fairing with just a few millimetres of space. As I discovered, this is the wrong approach. It seals the cockpit perfectly, which exacerbates the megaphone effect by forcing all the replacement air to be sucked up from the noisy engine bay below.

So I started experimenting. I loosened the clamps and slid the whole screen up the goal posts, creating a larger gap at the bottom.

And... it works! After a bit of trial and error, I found the sweet spot: a gap of about 1.5 inches between the bottom of the screen and the bike's bodywork.

The result is completely mad. At low speeds, you feel no difference. But as you get above 60mph, you start to feel a smooth, non-annoying stream of air flowing up from the gap. This airflow fills the vortex, and the result is that the faster you go, the quieter the engine noise gets. After an 80-mile ride, there was no ringing in my ears. Win!

So, Why Does a Bigger Gap Make it Quieter?

It seems totally counter-intuitive, but the physics are quite simple.

• Without a Gap: The big screen creates a large, turbulent, low-pressure void behind it. The only way for this void to be filled is for chaotic air to be violently sucked up from below, funnelling all the engine noise directly into your helmet.

• With a 1.5" Gap: You allow a smooth, controlled layer of air (a "laminar flow") to travel up the inside of the windscreen. This controlled airflow "feeds" and stabilises the low-pressure bubble, preventing the violent sucking action from the engine bay. The engine noise is no longer being amplified and directed at your head.

So, if you have a full-height screen and are suffering from that horrible engine drone at speed, the solution might be the opposite of what you'd think. Before you give up and buy a smaller screen, try raising yours up. Create a gap. It might just be the best (and free) modification you ever make.