Heated Scooter Screen ...

[Bluebottle]

Don't know what space has to do do with it but both Russia and the US used exactly the same pen.
Both planned to take pencils until somebody pointed out that graphite dust + electronics - gravity = fookin huge explosion.

Not so sure the airflow is so frequently mis-managed either.
Please don't tell me it should be a foil (wing shape) again because it really shouldn't, that isn't what they are trying to do

Getting back on topic there are some problems with trying to duct heated air to high/low pressure areas.
You can also get into trouble with higher performance stuff - a broken hose could get interesting, a broken hose where you have reduced the pressure around it can boil the coolant well below 100 deg .....and send through your ducting with explosive force.
Not trying to piss on your chips, just some extra stuff to think about

I look over my screen like most have said

[spaceprobe]

Most motorcycles these days are liquid cooled so you could easily fit a small heater matrix and electric fan somewhere.
Then you could duct this warm air up thru' the fairing so that it blows lovely warm air over your Hands
You could even extend it to blow onto the screen.......

This heater matrix is called a 'radiator' and already used as a heater on the SYM Joymax in fact.
Other manufacturers need to catch on...

And on the Maxsym's, but getting back to the windshield then if you were going to heat it because of vision problems you would also need washers and wipers. Perhaps because I am over 6'2" tall I have never had a screen that I have not been able to look over the top of, now visors and glasses fogging up is a different matter.

[PhilD]

OK .....

Looks like the discussion is heating up ... (Pun intended)

I decided to scrap the heated screen idea as a large can of worms that I don't want to open, but .... moving on to the water on the screen dilemma ...

How about an air knife? If the front of the bike was designed with a large air intake (Doesn't have to look like a bloody great shark ... could be under the front headlights), and the airflow was directed through a thin parallel gap in front of the windscreen, the airflow over it would be greater than the unducted airflow because of the venturi effect. That could increase the airflow over the screen enough to push the water droplets off.

A race car in the 90's had a similar system (Renault Spider) that used an air knife instead of a windscreen. Worked great to add to the aerodynamics, but you still had to wear a helmet on the road cos' stones and flies still hit you in the teeth.
I thought I'd keep the screen, but add the airknife.

Over to you ....

[Deleted User 796]

Don't know what space has to do do with it but both Russia and the US used exactly the same pen.
Both planned to take pencils until somebody pointed out that graphite dust + electronics - gravity = fookin huge explosion.

They both could have saved a few quid and taken crayons!

[StephenC]

Exactly - you need to design a lightweight heated screen with windscreen washers & Wipers!
After all, there was some sort of concept scoot around a while back (from Piaggio, or Peugeot) that had a HUGE screen, which was so tall it was almost a roof. Now had wipers & heating to that, its quite protective.

You can get that for the MP3 and there are a few knocking around central London with 'em. Bloody silly, IMO.

The screen should be lower than your eyes. The only time you'd need it higher is if you have an open face helmet. And in my opinion, using an open face is daft. But it is legal so if people want to, that's their choice.

[MrGrumpy]

OK .....

Looks like the discussion is heating up ... (Pun intended)

I decided to scrap the heated screen idea as a large can of worms that I don't want to open, but .... moving on to the water on the screen dilemma ...

Yeah....now that'll be a good challenge. 1st challenge, Design an effective screen - which seems to be something well beyond Yamaha's capabilities! Then 2nd challenge, design a high screen that is kept clear of water and road grime by aerodynamic effects - at all speeds - and be of high optical quality so that you can safely look through it even at night.
Once you've knocked those off, you can design a perpetual motion machine.....

[StephenC]

Indeed. In this day of parking sensors, auto lights and sat navs, we still peer through car windscreens on rainy days with the sole benefit of a bit of rubber scraped across it every few seconds.

It's a tough nut to crack, or wipers would have been replaced by something a bit more efficient.

[Bluebottle]

The air-knife screen on the Renault Alpine Sport Spider relies on the big slab of bonnet stuck out in front of it.
You don't get that luxury when designing a bike screen.
However, look at the laminar lip and Givi airflow in cross section and compare it to the air-knife screen

Plus a bike is tall and narrow rather than low and wide. The shortest route for displaced air is sideways rather than over the top - but at least that isn't pushing directly against gravity.

[PhilD]

I have to say guys, this is proving to be an interesting conversation, and really useful as research for my course .....

Thank You.

OK another idea ...

I wear a Downtown S helmet ... Yup open face ... my glasses mist up in a full face helmet.

The full face visor on that is coated somehow, so when it gets wet, the water just globs and runs off. I probably wipe it clean about once a month.
If that coating was added to a windscreen, that should give similar properties?
I take your points about the air knife not necessarily being too effective, but it should help to push the globules off the screen?
I get something like the effect using a product called Raincoat, but its a bugger to apply in cold weather and doesn't last too long ... And I'm adding to the scratching with all that rubbing. My helmet visor is unmarked, apart from where I scrape it being hamfisted.

Your thoughts are welcome guys!

[Bluebottle]

As well as coatings, there are "lotus effect" surfaces and films

Makes things self cleaning when rained on.