When is a big windshield TOO big?

[HondaInTheSun]

I bought my ST1300 used and it came with an additional larger windshield that the owner had never installed. The large one is 24 inches high, the one on the bike when I bought it is 18 inches high.

A couple of days ago I installed the bigger one just to see if I liked it, my question is, is it possible for a windshield to be so big that it's not safe? With the big one installed It goes up over the top of my head in the "up" position, and I'm 6'3. It's nice and quiet on the highway but I was super worried about it producing the dreaded ST weave, or other wind related issues, it looks like a sail. Do I need to worry about this, or should I just enjoy my new found cocoon? Truth be told this may be a good "winter windshield", great protection but not as much air on my front in the "down" position as the original shield. So will maybe keep the original one for summers.

Pics included for comparison, just really looking to know if anyone has one this tall installed, I don't want it to be a safety issue.

 

[Bush]

It's too big when you can't see over the top in your normal riding position. Just over the top, mind you, so that you aren't looking through a rain soaked shield, on those occasions.

Of course, with your power shield, I guess that becomes a moot point.

 

[jodog]

I think you're asking the wrong questions. The shields you have do not have a lip that "flips up" at the top. That type of shield throws the air over your helmet when you are looking over the top of the windshield. It doesn't matter how tall your shield is -- you need to be looking over it rather than thru it. Additionally, windprotection comes from how wide the screen is as well as how tall. The wider the shield the larger the calm zone behind it. This becomes important in winter when you would like to keep freezing wind off your hands. AeroFlow used to sell two screens for the ST, both with the flip at top and the wider one commonly called the "barn door" for it's size. Both worked well.

 

[HondaInTheSun]

Super helpful info here, thank you. With the screen in it's upright position, with me in a normal riding position, I am looking THROUGH it, to the point where the top of it is barely in my field of vision vertically. Maybe that's my answer to the "is it too big" question...

 

[SMSW]

"is it too big" question...

Never too big. Some of us here like to look through the windshield, some over. You need to decide what you prefer. Advantages of a tall screen are additional protection from rain, bugs, cold wind, quieter. Disadvantages are less air flow on hot days, riding at lower speeds in rain will not blow the water off the windshield, larger surface to clean/debug.
If your helmet flows marginal air (like my Schuberth C3), it will flow no air behind a tall windshield. (I often ride with my visor up with my shield also in max up position on the slab, and I drop the sun shade or wear sunglasses.)

I have a larger than stock (taller and wider) Calsci on my 1300 that I like a lot, and I look through the shield. I just bought a similarly large one for my V Strom that I look through, and I like that a lot more than the mini one that came on the 650. You need to set some parameters and then make your decision - or just mount it and try it out to see how you like it. YMMV.

 

[ST Gui]

I am looking THROUGH it, to the point where the top of it is barely in my field of vision vertically.

There's no stone tablet that says that's wrong. How you use it is your call.

There could/may be a problem if the windshield is so big that when in the fully lowered position you couldn't see over it. Being far from home and getting the windshield damaged so you couldn't see through it would then be a problem.

I always look through mine by maybe two inches. The keeps bugs and debris off my helmet visor.

A bigger windshield can reduce your MPG. Were it mounted on your handlebars steering input could be affected but that's not a given. How you load your bike whether or not you have a topbox or carry a passenger and your proximity to big rigs and the presence of crosswinds all may play a part in how the bike feels. I'm pretty sure the brand of oil won't be a factor.

Put it on and lower it completely. If you can see over it take it for a ride. Don't do a tonne right off the bat. Pay attention and see what feedback if any it gives you. Most complaints I've seen refer to the buffeting between the rider and shield and helmet noise. Earplugs help with the latter.

 

[ST1300 Alicia]

I saw a BMW K1600 with a windshield that was so big I did a double take. Holly $$$$ that windshield is big. That is when you know it's Too Big.

 

[Igofar]

Start saving your money to purchase a new windshield motor.
I would strongly suggest you NEVER move the shield while under way, or you'll be searching for a replacement motor.
I'll stick with my OEM stock shield, and my high 50's to mid 60's ave mpg thank you.

 

[Upt' North]

I bought my ST1300 used and it came with an additional larger windshield that the owner had never installed. The large one is 24 inches high, the one on the bike when I bought it is 18 inches high.

A couple of days ago I installed the bigger one just to see if I liked it, my question is, is it possible for a windshield to be so big that it's not safe? With the big one installed It goes up over the top of my head in the "up" position, and I'm 6'3. It's nice and quiet on the highway but I was super worried about it producing the dreaded ST weave, or other wind related issues, it looks like a sail. Do I need to worry about this, or should I just enjoy my new found cocoon? Truth be told this may be a good "winter windshield", great protection but not as much air on my front in the "down" position as the original shield. So will maybe keep the original one for summers.

Pics included for comparison, just really looking to know if anyone has one this tall installed, I don't want it to be a safety issue.

What's right for one will be wrong for another. Use the screen that provides what you want to achieve. I don't like too much wind noise on my 11 so the screen I use minimises the noise but allows a little air in. That's the way I like it. With your electric jobby this should be easy to achieve? I can't imagine looking through a screen whilst riding though.
Good luck.
Upt'North.

 

[Gug]

Start saving your money to purchase a new windshield motor.
I would strongly suggest you NEVER move the shield while under way, or you'll be searching for a replacement motor.
I'll stick with my OEM stock shield, and my high 50's to mid 60's ave mpg thank you.

I couldn't agree more. The bigger the shield the more wind resistance, the more resistance the more stress on the windshield motor. I had 130K on my 04' ST1300 and the motor worked fine. I adjusted it minimally on the run, slowed down when I had to adjust it and kept the stock shield.

I currently own a 18' Goldwing Tour and I have mentioned this truth about the windscreen on the forums. I am sitting in the bleachers now watching some really big shields being installed by many of the owners.

 

[ad.hom]

With the screen in it's upright position, with me in a normal riding position, I am looking THROUGH it, to the point where the top of it is barely in my field of vision vertically.

My screen isn't as high as yours, but if the top of mine is just below my eye line, I get so little wind that I can ride with my flip helmet fully open comfortably.

Sometimes if there's not much wind/traffic, I'll put it fully up & look through it. If the weather is bad, it'll stay lower.

My screen is smoked, and where I live it rains a fair amount. The slightest bit of rain on the smoked screen & you simply can't see through it.

I would strongly suggest you NEVER move the shield while under way

Maybe a little over zealous to only adjust when stopped. But setting a mental speed limit, above which you don't adjust, is sensible IMO. Personality, 30-40mph is ok, 70mph+ isn't (since drag is related to the square of speed).

If that means I burn the motor out, or otherwise need to buy a replacement, at least I'm acting with understanding of the situation.

 

[RaYzerman]

It's not too big IMHO if you can see over it in the down position. Nice to have extra adjustment in case of bad weather or cold.
There is a very old thread about making brackets to allow more air under the shield (similar to the Rifle idea) and tilting it back a smidge.... does wonders for calm air and no backpressure.
As for the weave, my spin on that is suspension is undersprung and need to add preload (or new springs front and back), along with adequate damping.... and the squarish OEM top box also has an effect, rounded Givis less in my experience. I wouldn't expect any bike with a top box to be completely calm at 100 mph.........

 

[Coop]

I may get a taller one for winter. I don't get the buffeting I got with the ST. Whatever floats your boat.

 

[bstig60]

I just replaced my stock shield on my 13 with a clearview with an adjustable vent. It's 2 inches taller and 3 inches wider and keeps a lot more wind noise away. I can adjust it where I look over or through and the vents allows air thru during the summer. BTW; my Goldwing, I always look thru that shield.

 

[heffly]

I think they're all too big. I have a clearview on mine, it almost never gets more than an 1" above absolute bottom position. JMO

 

[ST Gui]

I adjusted it minimally on the run, slowed down when I had to adjust it and kept the stock shield.

+1 Proper routine cleaning and lubing of the moving bits and their corresponding parts is a big help too.