[Mark S.]

Putt-Putt, on Jul 3 2008, 03:14 PM, said:

So if your at higher altitude there is also less drag on the spyder as well as anything else. So less drag less Hp needed this is your theory. So it kinda equals out according to what you say.

I theorize that because of its poor aerodynamics, Spyder owners will get better mileage by driving slower at lower altitudes, or if fortunate enough to live at a higher elevation will reap the benefit of lower parasitic drag. But I don't want anyone to take my word for it, I'm hoping we can get some data from the forum to support my theory.

Putt-Putt, on Jul 3 2008, 03:14 PM, said:

Did you know that a city bus has better arrow dynamics than a motorcycle? And by Quite a bit too.

I'm not sure what you're trying to say; it seems like you agree with me.

Putt-Putt, on Jul 3 2008, 03:14 PM, said:

Did you ever think about being a writer sure looks like you would like to be. Just my thought.

Putt-putt, are you poking fun at me because I take the time to check my spelling and punctuation? It won't work you know, I don't respond to beer pressure. I vow to continue chekcing my speeling -- and pukntuacion -- if yu dont lik it you can stop reeding!
Regards,

Mark

This post has been edited by Mark S.: 03 July 2008 - 09:29 PM

[Art]

Mark S., on Jul 3 2008, 08:25 AM, said:

I have a theory; it's all about speed and drag...

I wonder if folks might post their mileage along with the average altitude and speed they're driving -- if I'm right, those getting the best mileage drive slower and/or live at higher elevations. Here's why:

The Spyder is pretty wide across the front with a lot of things sticking out in the wind creating aerodynamic drag -- a force that acts in opposition to the engine trying to push you faster. This is called parasitic drag. The faster you drive, the more parasitic drag your engine must overcome. The amount of drag increase is not linear; it is proportional to the square of speed. All other things being equal, increasing your speed ten percent results in a twenty percent increase in drag. That means to overcome the parasitic drag your engine must produce ever increasing horsepower as your speed increases. The amount of horsepower required is different for each vehicle and is largely based on the overall level of parastic drag created.

Keep that in mind for a second while we talk about fuel/air mixture...

Internal combustion engines burn a mixture of fuel (gasoline) and oxygen. For your engine to run optimally, the ratio between the fuel and oxygen must be within certain parameters -- the engine control computer takes care of this for you automatically. How does this relate to altitude? Well, as the ambient air pressure drops with altitude, the number of oxygen molecules drops as well. The computer senses the reduction in available oxygen and cuts back on the amount of fuel going to the engine to keep the fuel/air mixture at the appropriate ratio. As you increase altitude, the computer is continually cutting back the amount of fuel to account for the reduced oxygen levels. That means the amount of horsepower your engine is producing at a given throttle setting drops with altitude. In other words, to make 50 horsepower requires more throttle at 6000' elevation than at sea level. Additionally, that means the maximum horsepower available also drops with altitude -- the throttle opens only so far...

"So what?" you say, "It takes X horsepower to go 80 mph, and it takes X amount of fuel to produce X horsepower. If I want to go 80 mph at 6000' elevation compared to sea level, I'll just have to open the throttle more to make the requisite horsepower; where's the fuel savings?"

Ahhhhh, not so fast Spyder breath! Let's go back to drag for a moment.

Our Spyders are not the most aerodynamic vehicles out there. Its designers didn't wrap everything up in nice, smoothly flowing sheet metal (like a car) to reduce drag -- where's the fun in that!??!! Auto manufacturers have come to realize over the years that because parasitic drag increases exponentially with speed, the best way to avoid the higher drag penalty of higher speed is to reduce the level of parasitic drag created to begin with. That's why the basic aerodynamic shape of many of today's cars is very similar; form follows function.

As I noted earlier, our Spyders don't start "clean," so to speak. They have wide front ends, with lots of drag-producing stuff hanging out in the wind. Spyders must push a LOT of air out of their way, and provide NO means of allowing the disturbed air to flow smoothly back together behind them. So what does this have to do with altitude?

There's a little-known fact airplane designers have been taking advantage of for years. The same thinner air at altitude which robs us of horsepower also creates LESS drag, and for the same reason: Because there are fewer air molecules. Fewer to burn, and fewer to push out of the way! In fact, drag reduction at altitude is one of the primary factors allowing airliners, which climb into the REALLY thin air, to achieve ground speeds in excess of 500 mph.

For us ground-bound unfortunates, parasitic drag reductions at higher altitudes means our Spyders need to produce LESS horsepower to go the same speed.

Now, keeping all that in mind, here's my theory.

Because our Spyders are so aerodynamically "dirty," I'm betting any reduction in parasitic drag -- by either slowing down or going to a higher elevation -- will have a much more significant effect on mileage than it would for, say, the average Honda Accord.

I'll start:

We average around 31 mpg. Altitude around here averages around 400' to 700' above sea level. We usually drive around 65 - 75 mph on the highway.

Regards,

Mark

I hope I'm doing this right - Otherwise, it'll be a big mess! i just got back from a trip back east from my home here in Colorado Springs (elevation 6035 feet). Below is the fuel stop location, elevation, and fuel economy. I started with about 700 miles on the clock, and rode about 2950 miles (+-).
Gas Stop Elevation MPG
Cheyenne Wells, Co 4300 31.69
Dresden, Ks 2908 31.93
Mankato, Ks 1617 31.55
Marysville, Ks 1283 30.17
St Joseph, MO 995 31.20
Williamsburg, Mo 773 30.96
Higginsville, Mo (Didn't automatically shut off - spilled a gallon or so on the ground!)
740 21.23
Hazlewood, Mo 604 33.63
Lincoln, Il 597 27.61
Dixon, Il 902 35.37
Woodstock, Il 923 29.54
LaSalle, Il 653 30.42
Atwood, Il 656 29.48 . . .
And then back home. Do you see any correlation?

Art

[Mark S.]

Art, on Jul 3 2008, 09:02 PM, said:

I hope I'm doing this right - Otherwise, it'll be a big mess! Art

Art,

No worries, thanks for sharing -- that's a great data point.

It looks like the majority of your trip was down here among us flatlanders, but Dude, 3,000 miles... that's quite a ride! You should have mentioned on the forum you were going to take the trip. I work in Hazelwood, MO right off I270 -- I coulda met ya for lunch!

Can you tell us what kind of speeds your were averaging? I'm assuming it was mostly highway.

I'd also like to know the speeds and mileage you average at home (at the higher elevations).

Aside from that, how did you enjoy the Spyder for a touring machine? How many days was the trip? Can you sit down right now, I mean without a pillow or anything?

Regards,

Mark

[Putt-Putt]

Looks like he got worse mileage in lower elevation (Ill.)

[Mark S.]

Putt-Putt, on Jul 3 2008, 09:49 PM, said:

Looks like he got worse mileage in lower elevation (Ill.)

Yeah, there's a difference, but I don't know if it's enough to be meaningful. I think we'll need more complete data to make a factual conclusion. If Art can provide us with speeds and an estimate of the winds, in addition to economy data for rides near his home at the higher elevations we might be able to do something.

Additionally, data from MORE forum members would add to the stats and give any conclusions much more weight.

Here's the breakdown of what we got from Art:



NOTES:

• I assumed the data from Higginsville, MO to be tainted and discarded it
  
• The two highlighted entries represent the greatest deviation from the average
  
• There is nearly eight MPG difference between the two entries with the greatest deviation
  
• The two entries with the greatest deviation occurred at similar altitudes
  
• The two entries with the greatest deviation were concurrent
  
• Economy at the highest elevation is not significantly different from the overall average

Because of these incongruities I must assume either:

• We don't have enough data to prove or disprove my hypothesis.
  
• My hypothesis is wrong.

I'm going with number one for now, but we need more data.

Art, if you can give us an estimate of your average speed and wind data (i.e. light/moderate/heavy, head/tail/cross, etc.) for each of these data points it would help tremendously.

Regards,

Mark

[Art]

Mark S., on Jul 4 2008, 07:48 AM, said:

Yeah, there's a difference, but I don't know if it's enough to be meaningful. I think we'll need more complete data to make a factual conclusion. If Art can provide us with speeds and an estimate of the winds, in addition to economy data for rides near his home at the higher elevations we might be able to do something.

Additionally, data from MORE forum members would add to the stats and give any conclusions much more weight.

Here's the breakdown of what we got from Art:

attachment

NOTES:

• I assumed the data from Higginsville, MO to be tainted and discarded it
  
• The two highlighted entries represent the greatest deviation from the average
  
• There is nearly eight MPG difference between the two entries with the greatest deviation
  
• The two entries with the greatest deviation occurred at similar altitudes
  
• The two entries with the greatest deviation were concurrent
  
• Economy at the highest elevation is not significantly different from the overall average

Because of these incongruities I must assume either:

• We don't have enough data to prove or disprove my hypothesis.
  
• My hypothesis is wrong.

I'm going with number one for now, but we need more data.

Art, if you can give us an estimate of your average speed and wind data (i.e. light/moderate/heavy, head/tail/cross, etc.) for each of these data points it would help tremendously.

Regards,

Mark

Hi Mark,

You are far more adept at analyzing data than I. In addition, since I am not a pilot, wind direction and intensity are factors I experience, but don't recall very accurately (wind blows all of the time the bike is moving - if it doesn't blow me off the bike, how bad can it be?). That being said, here are my best guesses:
From Colorado Springs (elevation 6035 ft.) to: WIND
LOCATION MPG ALT AV SPEED DIRECTION INTENSITY

Cheyenne Wells, CO 31.69 4300 50 CROSS MODERATE
Dresden, KS 31.93 2908 50 CROSS MODERATE
Mankato, KS 31.55 1617 50 TAIL LIGHT
St Joseph, MO 31.2 995 60 HEAD LIGHT
Williamsburg, MO 30.96 773 60 CROSS HEAVY
Hazelwood, MO 30.96 773 60 CROSS HEAVY
Lincoln, IL 27.61 597 60 CROSS HEAVY
Dixon, IL 35.37 902 60 HEAD MODERATE
Woodstock, IL 29.54 923 50 HEAD LIGHT
La Salle, IL 30.42 653 60 CROSS MODERATE
Atwood, IL 29.48 656 50 TAIL LIGHT


Additional notes:

Sorry, I couldn't figure out how to paste an Excel spreadsheet to make it look nice like you did. Also, I rode through some pretty heavy rains, accompanied by gusty winds, between Kansas City, MO and St. Louis. I had intended to ride straignt across U.S. Route 36, but in Cameron, MO, I turned South to avoid what was reported as water across the road, just east of Chilicothe, MO. As it turned out, that was an exaggeration. Water was only up to the shoulder of the road.

Art

[VBsypder]

I find something a bit odd about the spyder and gas mileage.

According to my serviceman/dealer the spyder runs lean, and typically when a motor runs lean you get more gas mileage.
I discovered this when I was troubleshooting my Vegas's fuel managment system. One of the symptoms that indentified a lean mix was an increase in gas mileage, and added heat. After changing the setting the bike got reduced gas mileage (2-3 mi), ran cooler, and was smoother.

Wish we could do this on the spyder.

oh, another thing, I found that when I break wind I get better "gas" mileage.

[Putt-Putt]

Jet propulsion not counted.

[charliebrown]

TJ_Spyder, on Jul 3 2008, 05:27 PM, said:

I am in Central Florida so most of the time barely above sea level. Most of my driving is between 40 and 60 some stretches 60-75.

I've tried to vary the shift points and cruisng RPMs. I read somewhere that allowing this engine to rev higher it gets better MPG. Nothing seems to make a difference.

BTW Ethanol level will also affect the MPG...maybe our gas is high??

My Spyder so far was 34MPG. Short rides etc. Went on a cruise Saturday, winds at 30-50MPH mileage went to 25. This was expected...Note I just have the small issue windshield. Im sitting like a sail for resistance..Our gas is 10% ethenal. I believe that doesnt help. Overall I dont get excited about the mileage. I just enjoy the ride. So there ....!! I spoke my piece... : Charliebrown

[smokster]

VBsypder, on Jul 9 2008, 05:52 AM, said:

I find something a bit odd about the spyder and gas mileage.

According to my serviceman/dealer the spyder runs lean, and typically when a motor runs lean you get more gas mileage.
I discovered this when I was troubleshooting my Vegas's fuel managment system. One of the symptoms that indentified a lean mix was an increase in gas mileage, and added heat. After changing the setting the bike got reduced gas mileage (2-3 mi), ran cooler, and was smoother.

Wish we could do this on the spyder.

oh, another thing, I found that when I break wind I get better "gas" mileage.

When I break wind, I just call it gas.

[bareman]

Danimal, on Apr 14 2008, 11:09 AM, said:

But you *could* strap a moped on the front of the Spyder and then use that to go get gas when your Spyder runs out !

With a 7.1 gal. tank I can go 200 miles before a fill up and still have 1gal+ in the tank. That's city and highway driving. I still indicate 1 bar.

[Rachmunas]

I only have about 450 miles on my Spyder and have filled it up with 1-2 bars at least 5 times or more already. The bars seem to drop rapidly when I drive.

I live in Ft. Lauderdale, FL so it's a decent amount of stop and go driving, but I always cruise and am not a roudy rider.

What's up??? Thanks!

[Bullet24]

I think it depends on how you are on the throttle as well, when i see people demoing the spyder they are usually really on the throttle when trying to take off from a stop, i mean reving it up as they s l o w l y release the clutch to engage and start moving. one thing i noticed on the spyder is that you have to almost completely let go of the clutch in order for it to engage. I asked the guy at the dealer if there was a way to adjust the clutch and he said no just my 2 cents

[spyderrider]

Bullet24, on Jul 20 2008, 03:44 PM, said:

I think it depends on how you are on the throttle as well, when i see people demoing the spyder they are usually really on the throttle when trying to take off from a stop, i mean reving it up as they s l o w l y release the clutch to engage and start moving. one thing i noticed on the spyder is that you have to almost completely let go of the clutch in order for it to engage. I asked the guy at the dealer if there was a way to adjust the clutch and he said no just my 2 cents

On my Spyder there is a small adjustment wheel right at the clutch lever. I adjusted it and found it a lot easier to use the clutch. The picture is looking down at the clutch lever.

[TJ_Spyder]

1900 miles now, 300+ with Hindle, last fill up: 28.2 mpg

[Bullet24]

spyderrider, on Jul 21 2008, 04:31 PM, said:

attachment

On my Spyder there is a small adjustment wheel right at the clutch lever. I adjusted it and found it a lot easier to use the clutch. The picture is looking down at the clutch lever.

I saw that adjustment but i think thats for adjusting the clutch handle itself in the sense that it pulls it closer to you so u can reach it, i played with it a little but it seemed like you still had to almost let it all the way out in order to engage the clutch. may have been the demo i was riding had just been abused or something

[Danimal]

Just enjoy the ride folks... MPG doesn't matter much when you're riding the coolest bike on the planet.......

[Putt-Putt]

Bullet24 You are correct that is just an adsustment hand size. Reach with fingers to lever. And mine just engages the clutch also when it is at the very edge of being all the way out.

[Putt-Putt]

Danimal, on Jul 22 2008, 12:09 AM, said:

Just enjoy the ride folks... MPG doesn't matter much when you're riding the coolest bike on the planet.......

At todays gas prices everybody cares about gas mileage! Don't matter what you drive or ride. I'm alwasys asked what does it get for gas mileage; always number 1 or 2 question asked by people. Even motorcycle dealers say it is one of the first things people are now asking now days. When buying a bike.

[Ray R]

Putt-Putt, on Jul 22 2008, 06:32 AM, said:

At todays gas prices everybody cares about gas mileage! Don't matter what you drive or ride. I'm alwasys asked what does it get for gas mileage; always number 1 or 2 question asked by people. Even motorcycle dealers say it is one of the first things people are now asking now days. When buying a bike.

Agreed. I'm almost embarrassed to answer "I'm getting 28-30mpg" when my wife's Civic is getting 34. Sure, the Spyder is faster, but it's also less than a quarter the weight. Even my 1200cc BMWs are getting around 50mpg.