Suzuki GS500 Fuel Economy

[low&slow]

Red Yaris, Thanks for the tips, I think I'll strip off the cover panels on the Vision and look at some attachment points for side pods and a taller & longer tail. i'm also thinking about making a new seatpad for a lower sitting position.
We are lucky to enjoy pretty mild weather here in the SF BAy area.
L&S

[redyaris]

I have ordered an O2 sensor kit and it should be here in a week or so. I am looking forward to what I will find out... although with all the aero mods I am doing I may not have time to instal it for a while.

[redyaris]

I have been making slow progress with the aeromods on the GS500, the things that remain to do are finish off the saddle cargo boxes and the behind the rider tapered fairing then relocate the rear turn signals stop light and licence plate then do some wireing. I will post some pictures in the em garage later.

[beatr911]

This is interesting. Installing an 8 gallon action packer storage container behind me (longways, not across the bike) gave a noticeable reduction of wind drag to my body. The wind drag (suction) is now transferred from me to the box. Having a long taper like you are doing should eliminate a source of drag and have some measurable benefits on FE, and provide lots of storage.

Keep going, post some pics if possible! We're really curious to see.

[redyaris]

Just did a test drive of the latest incarnation which is behind the riders back tapered cargo box, tapered behind the legs peaces and 17:33 sprocket setup, with the 7% bigger Rear Wheel. What I noticed is that with the low final drive gearing, and the lower rpm [4000rpm] at 110 km/hr [68mph] I have to shift down 2 gears from 6th to 4th to do any useful acceleration. The new gearing makes first gear strange in that I keep thinking I must be in second gear. I am hopeing to do a longer test ride to get some idea of the fuel consumption before going to Lacy for the FE rally. The weather we are haveing this spring is not conducive to motorcycle rideing, one day sunny and warm, next day snowing and the day after that thunder storms.

[redyaris]

Well the 2011 Lacey mpg challenge is over for this year, what did I learn?

1 I use 1 gallon to drive 82.7 miles through the countryside at an average speed around 40mph, 82.7mpg.

2 Driving mostly on the Interstate at 70mph +, on a 1594 mile trip I use 23.3 gallons of fuel, 68.4mpg.

3 The gearing is a little to low for the speed range I use most and I will be replacing the 33T rear spocket with a 35T rear sprocket so that the rpm are 240rpm higher. The bike engine does not respond well when the rpm drop below 3000rpm under load which is in the 50 - 70 mph useful speed range in 6th gear.

4 The top of the tapered cargo box is too shallow and has been changed to the 1:6 taper that is closer to the ideal. I may also make the front 2" narrower for better aero.

5 I will inclose a section below the tapered cargo box and move the tail lights to the rear of the bike. this should help reduce drag.

6 I will redo the side boxes for better aero.

7 Without making a few mistakes not much progress is made.

[redyaris]

My Solar oven is cooking supper and I am working on the latest incarnation of Gray, my 2007 Suzuki GS500F, I have put 3 new pics in the em garage and will try to upload the same pics to this post. I will be going on a 3000km [1875 mile] round trip next week and hope to get into the 80 mpg Zone at posted speeds between 100 - 120 km/hr [ 62 - 75mph], If I make the grade I will be ready for the Vetter Challenge.

[alvaro84]

Please post your experience when you're back! This new one you made is big... and may be effective. I'd also like to know how it handles in crosswind.

[redyaris]

I have ridden the bike 2500 km to Lacey Wa and back over the Rockey mountains with the upper section behind the riders back in all kinds of coditions and have had no problems in cross winds. In all my reading on the subject what I have come to believe is that the mass of the bike is an important consideration. The lower the mass the more sensetive the bike is to cross wind [F = MA]. If you look at a side view of a new Gold Wing you will see that its side area is LARGE, yet they are very stable in cross winds!

[low&slow]

Redyaris, Thanks for posting the pictures and very nice work !!. I got my front wheel fully faired in and made a taller windshield. Next I'll work on the tailsection, probably similar to what you have done. So far I'm not seeing huge improvements in mpg but the weather has been colld and rainy and I don't have any long rides lately. I do feel crosswinds a lot more. At first it bugged me a lot but now that I'm more used to it, its not too bad, kind of like riding on rain grooves.
I'll post some pix when I get a chance.