1982 GS1100GL Aero mods

[RiderofBikes]

K, hey all! Droppin by to post up my 2nd project this month. First of all, I just jumped right into this one... after modding my 2011 Fiesta and just scrapping by a few more MPG's than this bike, i knew i needed to do something!! lol

SO... To work I went!!

Started off buying another 4'x8' sheet of coroplast, and all done within 3-4hrs on a blistery tuesday afternoon(my back still feels it!, sunburn), had a rough idea in my head and just rolled with it.

First off, i drive this thing as long as its running! in almost every weather condition possible.

On to the bike...
A Standard 1982 Suzuki GS1100GL (8valve DOHC, D series motor) 5speed "shafty" Air cooled..

Main focuses for the fairing:
1.Decrease drag
2.Increase stability at high speed (I am not a squid)
3.Keep me dry as much as possible (rain suit either way)
4.Keep me warm (over achieving here)
5.Keep 2-up riding capability (yup)
6. ...Forgot this one
7. ...and this one too


When i bought it last summer

Rebuilt carbs over winter, adjusted accordingly, a little lean on mixture screws

Rebuilt forks. Changed to Superbike handlebar -6" heigt. Painted Lower fork tubes, wheel and disk rotors. Also rebuilt Break Calipers.

Cut 2"x1/2" woodstock and zip-tied to points on frame for Coro anchor points.(3 points used)
Cut out 22" high x 4' wide section of Coro wrapped around exhaust and engine.
Once anchored with the desired bend radius, I then trimmed the opening in the front for cooling. Also trimmed away the sides for my riding position. Legs tuck just behind the panel completely getting rid of any drag from my legs, my feet stick out from underneath the panel still causing drag.(better pics below)

Mounting bracket for the front for an earlier "Vetter" styled fairing. Secured with zip-ties around the forks.

Cut Coro panel to be made for the "Vetter" fairing. Once anchored was then trimmed for desired shape? Used woodstock for upper anchor points again zip-tied. Yeah i could of done better


Got Boattail?!
Ok, so heres where the fun began!
No idea in the world of shape, distance or width/angles to do for this, considering it isn't(me thinks) a consistant flow from the forward fairings. Considering I wanted to continue to be able to 2-up ride.

Started off by reducing weight and removed the center stand(cant get it on it anyways, not doing me any good. 145lbs vs. 660lbs=not gonna happen)
Cut out a small belly piece to go in front of the rear tire to close that space off.

Worked on the sides, little trimming needed around the shock bolt and turn signal and left over hanging under the exhaust line.

Did the best i could to continue the boattail's ending point and distance beyond the rear tire.


ALL FOR NOW, will finish this post once i get home from work tonight!!!!

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
EDIT: O-K... Home from work, nice and soaked! Saw it comin
So i believe ive failed at "Keeping dry", need to redo the front anyways for better flow/rain/water protection, as well as do a new front fender. Gettin a rooster tail from it straight up and into the helmet...

So back to pics just a couple left...

Here is a side view. A good overall look with the Mid-fairing and the length added by the tail. I'd have to say, the mid-fairing works a bit too well in dry conditions. It gets a bit warm, and my shins tell me... So I know I may need to add a couple outlets for passing air OR cut away from the front opening for better cooling. I do plan to add an Oil-cooler to it soon. Pick-n-Pull will become my friend with that project!


And here's where the difficult part came in...
I hate having it like it is, but i had to keep the tail-light the way it was and came up with a solution for my license plate to stay under the "lighted" area...
Once this was done i was able to kinda work with what was left so i just added strips to the side of the light, creating a "channel" for air to flow through the 2 sections... would like to do a full height tail but will have to wait for now...

I certainly don't know if this was/is a good idea. Seemed it was better than nothing. Don't quite know about the upper section, if its even needed so ill leave it for now.


ALL of this work is held on by zip-ties, and can be takin off in less than 1 min... So easy on/off, just gotta keep zip-ties on me(which is a necessity for me anyways!)



Anyways.... after 5 days and a few tanks later(w/2-up riding=15%), I've figured i've reached a 30% MPG Gain!!!!

(Control) Stock ~40mpg @ 70mph = 5th @ 4100 rpm (with tuck)
Faired ~53mpg @ 70mph(+/-5mph) = 5th @ ~3800 rpm (with tuck)

***I DO NOT have a WORKING Speedo!! So I cannot accurately track my miles, and I calculate Drive gear + RPM's = mph(+/-5mph with fairing)***

I have been using Google Ear*h for my distance calculations(from home to work/back + an afternoon ride with the Gf) 80% highway...

I know for sure there is potential for greater numbers!

[Frank Lee]

You have done origami before?

[RiderofBikes]

Originally Posted by Frank Lee

You have done origami before?

Arts and crafts my friend

[RiderofBikes]

Sorry still a bit new to the whole Cd, rolling resistance, etc math and equations stuff... So one day i might actually get that info up, but its all still a work in progress.
But I did a few test rides today with a friend, learned my analog Tachometer is a little off by a 200-300 RPM's.(Reads lower)
Also did some 20mi trips all Hiwy and matched speeds with him. Indicated 70mph @ 4100rpm w/fairing instead of what was mentioned above(guestimated)

So from this new more Correct Info, my best "guess" is that w/o the fairing my previous 70mph speed was more around 4500-4600rpm...

Also ran into more "normal" head/cross winds today than i have the entire previous week... At the end of the runs, I calculated ~47mpg. This leaves me to figure i must have had a cross/tailwind giving me a boost in my previous calculation.

Aw well, a gain is a gain now to drop those RPMs down a notch...


Anyone have some Guru knowledge about making a better asymmetric front fairing? more like an LSR fairing, from airtech-streamlining or others. BUT with extremely basic tools and materials? I've thought about Expanding foam, and carving away whats not needed, seems best to me for a positive fiberglass mold.. any other ideas would be nice?
Thanks

[Frank Lee]

Also did some 20mi trips all Hiwy and matched speeds with him. Indicated 70mph @ 4100rpm w/fairing instead of what was mentioned above(guestimated)

So from this new more Correct Info, my best "guess" is that w/o the fairing my previous 70mph speed was more around 4500-4600rpm...

Fairing/no fairing/pulling a drag chute doesn't matter, your rpms are going to be the same at x speed.

[Christ]

Originally Posted by Frank Lee

Fairing/no fairing/pulling a drag chute doesn't matter, your rpms are going to be the same at x speed.

Given a 1:1 static relationship from engine to driveline. Most automatics without lockup don't allow for this, and as load increases, RPM increases without a speed increase (to the extent that fluid shear allows).

[Frank Lee]

The bike has an a/t?

[Christ]

OP - Just a comment about the center stand thing - They're leveraged so that very little lift and a slight rearward attitude is all that's required to put a bike on a center stand. If you practice it a few times, you'll get it. However, they're less than necessary, especially if you have stands at your disposal (or wood blocks, in your case), so good onya for getting that extra 10-15 lbs off there (provided you cut the brackets off, too.)

If you didn't cut the brackets, you can often just "jack" the rear of the bike up and slide a pin/punch through the holes that retain the center stand to use it without keeping it installed.

[Christ]

Originally Posted by Frank Lee

The bike has an a/t?

Not that one, but some do, most notably several Honda bikes, new and old.

I'm guilty here of reading the comment without context, however.

[bschloop]

expanding foam works great for a plug if you want to make it out of fiberglass, and you will want more of a fixed fairing design like the windjammer fairings were. come to think of it, you might be able to find an old windjammer, and mod it using coroplast with pretty good results. they were made specifically to fit your bike which is a big plus.