Introduction & Cross wind solutions to motorcycle Streamliners?

[P-hack]

Don't forget CAD (Cardboard Aided Design), make it a duck tape sandwich composite for strength/weather. Hot glue (or more duck tape) for attachment, 1" high, follow the fairing from the bottom of the windshield to the bottom of the fairing I recon.

[Teri_TX]

Hi Ironside,

Theo and Allert re-sell the stall strips (storm strips) at their business. I believe some other Dutch velomobile enthusiast manufactures them.

Otto's suggestion for drywall corner protectors is what I would use here in the US. Home Depot and Lowes may not have outlets in England but I'd be surprised if the local "home improvement centers" in England didn't have the same thing. If they don't, a specialty supplier to companies that cater to that business would.

If your curves are of short radius, a heat gun would assist in the bend as the drywall corner protectors here are made of acrylic or styrene plastic and would only bend to a fairly gentle curve. Just don't overheat the plastic.

As Otto suggested, some double sided tape would make attachment easy or if you don't care about the looks (temporarily) just stick them on with a suitable strong single sided tape.

As I have suggested before, a simple vertical fence would be a degenerate form of a stall strip. A suitable flexible strip of plastic or wood taped down would serve for testing purposes. "V" notches , stegosaurus look? would aid in forming a short radius curve. Again, for testing purposes, looks are irrelevant.

Otto's other suggestion to add yarn tufts would be of a lot of interest. Vetter has a very clever method of "mass producing" yarn tufts he details in one of his chapters on his "Last Vetter Fairing". Edit: I found it in chapter 25.

-- Teri

Originally Posted by Ironside

I don't know the optimim size or location, so I thought I could experiment with a stick on plastic strip.
Does anyone know what Theo uses?

Originally Posted by Otto

Try clear plastic L shaped corner piece used to protect corners of sheetrock walls in houses. Comes in 8' lengths, straight but somewhat flexible.

Very cheap at Home Depot or Lowes. Stick on with two-sided carpet tape or sticky foam tape. You could add yarn tufts, record the effects with GoPro camera.

[Teri_TX]

Hi Bschloop,

I (and everyone else) would be very interested in some real world A-B-A testing of stall strips on an actual streamliner fairing.

Other than Theo's postings and Dutch blogs on "storm strips" (same thing), all has been theoretical musings since I first posted the idea.

Originally Posted by bschloop

I just found this thread, and I would be happy to test a "stall strip" on my fairing, As soon as the snow melts and my bike is back together. It should be only a week or two now.

Alan and Vic's bikes also have one other thing in common. They are both kawasaki ninjas underneath. It would seem that weight distribution and steering geometry might be more favourable for them compared to other setups. Craigs helix is less than ideal because of its basic design ie. low center of gravity, very small wheels. These are great bikes to compare since they all have the same fairing (for the most part)

Interesting observation. I'm not a motorcycle rider so I have no first hand knowledge and I admit I haven't considered the dynamic aspects of mass distribution. In all, motorcycle design is a very complex system dynamics problem.

Alan's latest project design lengthens the wheel base and weight distribution is changed. We'll have to see how it works out.

I understand the use of Kawisaki Ninjas as a mule due to their cheap availabilty, but for better FE, a single cylinder motor like the Honda CBR 250R's should be better. Not having a screaming engine under or in front of me would be a plus as I'm anything but a wanna be "boy racer". I hear them screaming down the highway near me often in the spring and fall here while waiting (hope?) to hear the scream suddenly stop in a crash.

-- Teri

[Ironside]

Found this while searching

MOTORCYCLE BIKER HELMET STICK ON SPIKE STRIP MOHAWK LONG CENTER SPIKE | eBay

should frighten the jaywalkers.

Thanks Teri, I've found suppliers of T section trim and D section conduit that will do the job, also stick on chrome trim which could be used without painting, all available for pennies. I was a scientist in a previous life, so a little experimenting is in order I think.
Also I must thank you for starting this thread, it came at a very opportune moment for me.
Regards
Pete.

[Teri_TX]

Hi Pete,

Originally Posted by Ironside

Found this while searching

MOTORCYCLE BIKER HELMET STICK ON SPIKE STRIP MOHAWK LONG CENTER SPIKE | eBay

should frighten the jaywalkers.

I love it! Stall strips for helmets!

Thanks Teri, I've found suppliers of T section trim and D section conduit that will do the job, also stick on chrome trim which could be used without painting, all available for pennies. I was a scientist in a previous life, so a little experimenting is in order I think.

"D section conduit"? Is that for the add on surface wiring when the power wiring in a building isn't readily accessable?

Also I must thank you for starting this thread, it came at a very opportune moment for me.
Regards
Pete.

You're welcome!

Regards,
Teri

[Ironside]

Hi Teri,

The conduit I mention is exactly as you describe, I'd prefer to go with a stick on chrome strip (easier and better looking), with a double sided sticky foam tape underneath so that it stands 5 or 6 mm proud of the surface.
I don't know the minimum effective thickness or best cross section shape of the stall strip, so this is the plan :-

1. Make some tufts (Chapter 25 as you said) and stick them down one side.
2. Tape down a piece of rope along the centre line (I have 7mm rope laying around).
3. Rig up a large extractor fan to mimic the wind from different directions and at various angles of lean.
4. Post the video here so that people with more knowlege than me can analyse the results, and hopefully advise accordingly.

Any suggestions before I start?

Pete.

[Teri_TX]

Hi Pete,

Originally Posted by Ironside

The conduit I mention is exactly as you describe, I'd prefer to go with a stick on chrome strip (easier and better looking), with a double sided sticky foam tape underneath so that it stands 5 or 6 mm proud of the surface.
I don't know the minimum effective thickness or best cross section shape of the stall strip, so this is the plan :-

1. Make some tufts (Chapter 25 as you said) and stick them down one side.
2. Tape down a piece of rope along the centre line (I have 7mm rope laying around).
3. Rig up a large extractor fan to mimic the wind from different directions and at various angles of lean.
4. Post the video here so that people with more knowlege than me can analyse the results, and hopefully advise accordingly.

Any suggestions before I start?

Pete.

Your plan is as good as far as I'm concerned.

The height of stall strips is something best determined experimentally as no one here is a PHD brainiac aerodynamicists with years of wind tunnel use (I'm sure someone will falsely claim such curriculum vitae). Just plan on a few experiments with various shapes and sizes. Tuft pictures of the experiments might show something obvious.

Edit: For your tests at various angles, remember the vector sum of a side wind and forward velocity. Tony Foale Tony Foale Designs, article on motorcycle aerodynamics. gives an example of a 15 mph side wind and 75 mph forward speed results in an apparent wind of 76.5 mph at 10 degrees to the over the road direction. I don't expect your fan has such power to make a 76.5 mph wind but the angle is a good start. The idea is to study how your stall strips ruin the airflow on the down wind side and presumeably the unwanted lateral lift. The tufts should indicate turbulent flow at the body surface. Some one has pointed out tuft testing isn't the whole picture but it's a start. Smoke generators are more problematic although possible for some one with excellent shop facilites.

THEN ... road test! As Visionary asked, how do you quantify the results? I don't have an answer at this time. Your best impression is about as good as any opinion on this forum.

Regards,
Teri

[Ironside]

I didn't think I'd be posting again so soon, it was another blustery day today with avg. wind speed of 22 mph gusting to 35, similar to my last test run, but with squally shower of rain and hail. A chance too good to miss for a direct comparison.
I took a piece of 7mm rope and taped it down the centre line of the fairing, and went out for a run.





I honestly didn't think such a small change would have such a dramatic effect.
Yes the bike still moved around, but not nearly as much as previously, at no time was I even a little concerned.
In an attempt to quantify the result, I'd say that the bike was affected only by gusts strong enough that I could feel on my body, this was not the case before. I might even go so far as to say that it was not a lot different from riding a 'naked' machine.
Further experiments are planned before a permanent strip is installed (would bigger be better?). Based on today's results but I'd be quite happy to call this fixed.
My camera battery is flat and I can't find the charger , so there will be a delay before posting the tuft testing video.
By the way, apart from my shoulders, the fairing kept me warm and dry.

[Teri_TX]

Hi Pete,

BRAVO!

Originally Posted by Ironside

I didn't think I'd be posting again so soon, it was another blustery day today with avg. wind speed of 22 mph gusting to 35, similar to my last test run, but with squally shower of rain and hail. A chance too good to miss for a direct comparison.
I took a piece of 7mm rope and taped it down the centre line of the fairing, and went out for a run.





I honestly didn't think such a small change would have such a dramatic effect.
Yes the bike still moved around, but not nearly as much as previously, at no time was I even a little concerned.
In an attempt to quantify the result, I'd say that the bike was affected only by gusts strong enough that I could feel on my body, this was not the case before. I might even go so far as to say that it was not a lot different from riding a 'naked' machine.
Further experiments are planned before a permanent strip is installed (would bigger be better?). Based on today's results but I'd be quite happy to call this fixed.
My camera battery is flat and I can't find the charger , so there will be a delay before posting the tuft testing video.
By the way, apart from my shoulders, the fairing kept me warm and dry.

Other than Theo's report on his velomobile, you're the FIRST Ecomodder to test and report on a stall strip like device on a dust bin type fairing. I wish I could give you something more than a thanks on your post!

A few more tests on maybe a bigger rope or similar might give you an indication if bigger is better

However, I'd still be cautious about taking on big lorries (18 wheel trucks for Americans) without more testing.

Regards,
Teri

[low&slow]

Hi Teri, Welcome to Ecomodders! Interesting discussion about the storm strip in front of the nose. I got into streamlining almost 4 years ago and have enjoyed some success with my bikes. I started with a 1982 Yamaha 550cc Vision got it up to 66.8 mpg then switched to a 2000 Kawaskai Ninja Ex250. With the Ninjette I've gotten a best tankfill of 146 mpg and have Vetter Challenges runs of 130 mpg( 2013 MidOhio, 4th Place) and 119mpg ( 2012 MidOhio, 2nd Place) . I ride my streamliner on a regular basis and have ridden it from the SF Bay area to Kentucky and back. I run a Vetter fiberglass nose and I built a Vetter-style tail using plywood, doorskin and fiberglass. I'm good friends with Craig Vetter, Alan Smith Terry Hershner and Fred Hayes.
Craig's , Alan's, Terry's and mine are pretty similar in profile. All us do pretty well in windy conditions though Craig's struggles a bit more than ours. We suspect is due to the Helix scooter steering geometry , low center of gravity and small wheels.

I agree that the Honda cbr250r is a good choice as your base platform. Single cylinder , fuel injection and water- cooling are all desirable features. Sendler has had great success with his. The Ninja 250 is cheap, durable and does surprising well despiteits sport tuning. Good luck with your efforts !