Bit by bit, joining the aero club
 

Vic Valdez (low&slow) brought me a little gift when he passed through Utah on the way to Ohio - A couple of Alan Smith's old aero parts.

I plan on cleaning up the parts I just attached, changing the gearing, and making an aero tail for the bike.

Have not checked mileage yet. However; one thing has changed, when you ride an aero modified bike you do not blend in much. I get lots of questions from folks when I am parked. :p

So far:

https://lh4.googleusercontent.com/-k...2/DSCN0888.jpghttps://lh6.googleusercontent.com/-u...2/DSCN0887.jpg

Jeff

Good to have you !

Is it a 250 ?

Yes, 2005. :D

Do you notice any difference in cross winds?

Looks good, but I'd ditch the saddle bags and go with storage behind you instead if you are looking for the best aero you can get.

Not sure. Yesterday, I rode home in crosswinds that were gusting from zero to twelve mph. It seemed that with the increased side area up front might have made the bike a bit more sensitive. However, I rode in heaver crosswinds earlier in the week (gusting to the mid twenties) and the bike seemed solid. :confused:

I'm sure that when I add a tail the stability will increase. :thumbup:

jkv357 - Yep, those bags are way draggy (so are my legs) but for now they will have to do. I do not have a top case.

Jeff

what's your typical ride ?

Currently - Mostly a short work commute with canyon runs for fun :thumbup:

I am planning on doing some longer rides in the future. If it works out I may join Vic and Alan in Vegas for the next Vetter Challenge.

Edit: Riding home from work the winds were gusting 16-20mph and the bike is more sensitive.

Jeff

I would blame the front wheel fairing first for the side wing sensivity.

Short rides, I don't know the impact of streamlining since it adds weight.
Looking forward to seeing your personnal results.
Where is your fuel log by the way ?

Jeff, It looks great! :thumbup:The adding a tail will help the current wind sensitivity.
I got back from OH/KY yesterday, I'm glad you are putting the new aero parts to good use. I hope you can join us in Las Vegas for the next Vetter Challenge.

I agree that the wheel fairing is most likely the root of the instability.

As I stated, the bike is currently used mostly for commuting. However, I see some long trips in my future and hey, it is fun to experiment and to try different things. In my mind, why have a stock bike and go with the flow. :D

I suppose I will add a log when I get to it.

Jeff

This bike looks awesome, to me. Often (some) modifications don't make something look better, but this looks very slick. The craftsmanship with the original bike looks great.

Been following, but seeing this bike (again) forced me to state it!

Stability improves when there is more fin area behind the steering axis than in front of it.

Side wind guts interference gets much less when the front wheel is covered by a fixed nose.

Thanks for the replies. I agree, adding a tail will improve stability. Alan had a Vetter tail on the bike and he stated he had no problems with stability.

From the Vetter site: 2011 Vetter Streamliner-Chap 50

Alan stated: "Passing semi-trucks usually caused a minor wiggle. I think that I have been lucky to have a stable motorcycle to start with. Very strong continuous cross wind did push me around but not something that I could not handle. Just lean into the wind and continue at speed."

I will not try to reinvent the wheel and will be going for something similar to Alan's bike, shown here, with the windscreen and wheel fairing:
http://www.craigvetter.com/images/20...-Ninja-400.jpg

Have you done any before/after aero mods mpg comparisons?

I would like to see some numbers with a stock Ninja and a aero-modded one in the same conditions.

What amount of mpg improvement are we talking with what you've got there?


Jay

Jay, in the photo above, Alan was getting, I believe, around 96mpg.

I have not been riding too much with the new nose on my bike (work + family vacation) so I haven't gauged fuel consumption yet.

Jeff.

Update
 

I got to work on the tail section. After a little CAD (Cardboard Assisted Design) work I have created the main and tail bulkheads. I am using 1x2 stringers to tie the bulkheads together.

This is a small start and only took an afternoon to accomplish. I decided on a simple wood structure, well, because it is simple and I have the hand tools to accomplish the work.

I will cut lightning holes in the bulkheads and will be using steel supports to attach the structure to my bike. I am attempting to keep the stock seat in place.

https://lh4.googleusercontent.com/-w...1827.jpg?gl=US

https://lh3.googleusercontent.com/-D...1828.jpg?gl=US

https://lh3.googleusercontent.com/-T...1831.jpg?gl=US

Jeff, Looking good!! Once You start running with the tail you will your wind sensitivity much improved.

Looks like 116 mpg...

Work continues. I lightened the main bulkhead, test fit some stringers, and played around with the cargo shelf.

I priced corrugated plastic board and .032 aluminum for the skin: 4X8 sheet of the fluted plastic is $13 and a 4X10 aluminum sheet was $45 (I think). I am leaning toward the aluminum but the fluted board is tempting.

Next: Mount the main Bulkhead.

Photos (ignore the extra long stringer sticking out the front of the bulkhead it will be cut off) with a grocery bag to check if 4 of them will fit in the cargo area per Craig Vetter Challenge rules :):

https://lh3.googleusercontent.com/-b...1842.jpg?gl=US

https://lh3.googleusercontent.com/-u...1841.jpg?gl=US

https://lh3.googleusercontent.com/-F...1836.jpg?gl=US

Nice !

boat tail
 

Darn! There goes Exxon/Mobil's next quarterly profits!:p

I have the tail a bit more fleshed out. I need to finalize the mounts and glue and screw the whole bit together including a cargo shelf behind the main bulkhead. I will cut a couple of lightening holes in the mid-bulkhead. I am trying to keep it as light as I can especially as I go towards the rear of the tail.

Following the main assembly I will be painting/sealing the frame (for water resistance) prior to complete skinning. I think I have settled on using door skin for the sides of the tail and Coroplast for the top and bottom. I also need to fab up an inner fender for under the tail.

After that, I will wire up the lighting and change the gearing on the bike. I will either go 15/41 or 15/39 (the latter requires shortening the chain).

Other than the big things the rest will be polishing up the details. :)

https://lh3.googleusercontent.com/-O...1857.jpg?gl=US

https://lh5.googleusercontent.com/-9...1859.jpg?gl=US

The LED tail/brake light I will be mounting on the end of the tail. Tail/Brake Light Bar | Trailer Lights & Lamps | Truck/Trailer | Super Bright LEDs
http://d114hh0cykhyb0.cloudfront.net...r-blb-r9-7.jpg

https://lh3.googleusercontent.com/-O...1860.jpg?gl=US

https://lh4.googleusercontent.com/-A...1861.jpg?gl=US

https://lh6.googleusercontent.com/-y...1862.jpg?gl=US

Looks promising, plenty cargo space !

May I suggest a diagonal brace between the frame tubes underneath the rear saddle and the middle bulkhead ?

In the bottom picture, it looks like it's made to have a brace there, by continuing the frame tubes.

Thanks euromodder, that is exactly what I am going to do :thumbup: However, I plan on using the frame mounts for the top of the exhaust hanger + another mount just a bit lower to create a triangular brace to the mid-bulkhead. There are three in-line bolts there. You can see it just below the frame tubes you mentioned.

Plus, I will be adding a bracket connecting the bottom of the main bulkhead to the bolt where the exhaust hanger/rear foot peg mount is located. On the rear portion of the tail have a thin diagonal brace going from the bottom corner to the top of the mid-bulkhead.

Jeff

Update.

I have been doing a ton of looking at, and thinking about, the tail structure and how to mount it and make it stiff enough to actually work on the road.

All this thinking, of course, causes additional head scratching when you realize your original ideas may not work or may not be safe. Every idea causes compromises and these must be thought out.

Sometimes I build in a fury as the ideas come quickly and other times I feel quite stumped. :confused:

At this point, I now think I have solutions for the tail to be mounted in a safe manner. Last thing I want is to have the tail come loose or break apart if I hit a bump or something. :eek:

Stay tuned, I really want to get this thing finished so I can join greenaero and Alan Smith in Vegas for the next Vetter Challenge. However, I believe I am behind schedule but would rather be safe than sorry with a build of this nature.

Edit. >>> I will not be able to make it to Vegas due to work commitments. Oh well, maybe next year. <<<

Jeff

If possible, lose the barn door mirrors, replace with smaller, more aero shapes available pretty cheap on eBay, which also has combined mirror/turn signals. Also, note the mirror stalks' cross-section, and convert to teardrop airfoil shape.

A tankbag is handy to carry stuff, and fills in the gap between rider and windshield, where a low-pressure bubble forms and collapses, aka von Karmann vortex. A tankbag in that gap much reduces the buffeting and turbulence there, making for a much smoother and quieter environment inside your helmet. Less drag, too. This is akin to the fairings between cab and trailer on big trucks.

As others have noted, lose the rear hardbags and carry your stuff in your new tail section, or at least make a free-blown teardrop fairing behind the rider, that acts as a backrest for him and a stowage trunk for junk. I suspect your tail section fairing would work as well if only about half that long, and be lighter, cheaper, and more manageable.

On my BMW I may delete the stalk mirrors entirely, and mount mirrors to the windscreen inside the upper edge, sorta like fighter plane mirrors mounted inside the canopy bow, for less stuff hanging out in the breeze.

And, like my BMW R1100RSL, your bike has a big concave gap between headlight and front fender, which acts like a very efficient speed brake. I don't know what BMW was thinking, as the heat to be dissipated is on the boxer cylinder heads, not up in that big hole. Your bike may need the big hole to cool the engine, though. I used a semi-circular section of a plastic bucket, flattened it somewhat into an airfoil shape, and attached it to the front fork struts. This turned that huge speedbrake hole into at least a crude airfoil shape, reducing drag and buffeting significantly. I get about 51 mpg cruising at 80, ~10-15% better than other similar BMW bikes at 70.

Would you have pics of your bike ?
Not that I can't imagine how you had it done, but a pic is always nice to look at.

Was planning on going to smaller mirrors mounted on the back of the windscreen near to my helmet. Alan Smith uses small mechanics inspection mirrors. Pretty easy to fab-up a mount and attache the mirror end.

http://c.shld.net/rpx/i/s/i/spin/ima...sm=0.9,0.5,0,0

I roll with a tank bag all the time. :)

Luggage will go in the tail section behind the 1st bulkhead. It should hold 4 grocery bags worth.

I like the idea of mirrors inside the cockpit. Like this, no?

https://lh4.googleusercontent.com/_V...CP9k/fc016.jpg

The canopy bow mirrors you show above are precisely what I have in mind. They're out of the breeze, so reduce drag.

And, thanks for noting the mechanic's mirrors, which also could be useful: Their telescoping stalks could be modified as windscreen stays or struts, so you can adjust the angle of the windscreen by using the telescoping mirror handles with some sort of clamps that lock them at a desired length. (I'd thought about using worn out gass-filled hood or trunk shocks, with one on each side of the upper windscreen, and adding a locking mechanism. Twist-lock telescoping mop handles area also considered.) But, now that you've mentioned telescoping mechanic's mirrors, maybe they could serve both as adjustable mirrors and as windcreen struts.

Some motorcycles such as BMW R1200RT have electric windscreen adjustment, which no longer seems a luxury after using for, say, 2 minutes behind a big truck. My R1100RSL bike has a manual twist knob adjustment, but it does not work well. I have no idea how your bike and windscreen works at highway speed, but this will be a major factor to consider if you travel much. Getting dope-slapped by buffeting is no fun, tiring, and noisy. So, any thoughts on improving windscreen adjustment are much welcome.

Here's a pic of a bike basically like mine, except for the lower fairing. Note the huge hole between the front fender and the headlight fairing. That thing is effectively a drag chute. I used a semi-cylindrical section of a plastic bucket and attached it to the front fork struts, making a D section there to smooth the airflow in that area.
http://www.google.com/imgres?hl=en&b...2&tx=105&ty=70

Otto, how about these: Riderscan Mirrors.

I imagine it would work well in conjunction with a small bar end mirror for legality purposes.

http://www.huntercreate.com/Images/p....08Russell.jpg

I originally saw them on the Roadcraftnottingham YouTube channel:

[youtube]i9ULxS8Iss0[/youtube]

Found some great little bar-end mirrors that are made for bicycles. by taking off the bar-end fitting they fit perfectly and are completely adjustable. They are slightly wide-angle and even though they are very small, they provide a pretty good view because they are close to me.

I should have the tail mounted (after much thinking and revising the mountings hard-points and structure) in a week or two and hopefully on the road next month (crossing fingers and hopefully the snow will not be on the roads :( )

https://lh4.googleusercontent.com/-F...2207.jpg?gl=US

https://lh4.googleusercontent.com/-T...2213.jpg?gl=US

https://lh5.googleusercontent.com/-x...2211.jpg?gl=US

Cheers, Jeff

More work done. I think I have the mounting system for the tail figured out. Some bits-and-pieces to figure out but the whole of it is there.

the front of the frame will tie into the main bulkhead and I will probably run a couple of braces from the back of the tail to the frame of the bike.
https://lh3.googleusercontent.com/-4...2229.JPG?gl=US

https://lh3.googleusercontent.com/-M...2223.JPG?gl=US

Is the tail a little lower than your shoulder ?
Seems very tall to me.

Top of the bulkhead is right at the top of my shoulder. I am 5' 10". I will be placing a "headreast" above that to hold my license plate and turn signals.

Jeff

No seat height to be gained on foam thickness ?

For now it is fine how it is. I'll probably do a few things different in version 1.1. Looking at the profile view I think I will change how far the bottom of the middle bulkhead goes down below the lower stringer.

Are you going to fair in the rear wheel completely as well ?

If not, how about reducing the width of the lower part of the tail ?
It need not be any wider than the rear wheel (or swing arm) in that case.
You could also bring it closer to the far of the rear wheel.