It took me a while to figure it out
Pete,
I know the aggravation of having to do a commute at a specific time over a specific route regardless of traffic congestion. Fortunately, I’m retired, and have the luxury of riding when I want and where I want.
I’ve learned a few things about the Bandit. It’s the heaviest bike with the largest motor of any bike I’ve owned. Its fuel consumption characteristics are similar to an automobile in some respects. After all, the motor is rather similar in design to many small four-cylinder cars.
In the mountains, or on roads with curves, I don’t usually throttle it on coming out of a curve (although it is a lot of fun) just to hit the brakes going into the next curve. I just select a suitable gear and maintain a rather steady throttle setting and I seem to move along as fast as the rest of my riding buddies except under full-race conditions.
Running a steady speed at even 70 - 80 mph delivers good fuel economy. This surprised me, because other bikes I’ve had get thirsty at higher speeds. Repeatedly getting up to speed from a stop in traffic and then having to slow down eats up fuel as I expected. It’s unavoidable at times, but I’ve found it can be mitigated to some extent.
I’ve found that a light application of the throttle delivers better fuel economy than taller gearing when operating in the lower half of the engine’s rpm range.
I used to ride in as high a gear as possible, thinking a higher gear delivers more miles per gallon. This turns out not to necessarily be the case. On level ground or downhill when I can run a taller gear and still keep a minimal throttle opening, I do get better fuel economy. But when I have to apply significantly more throttle to pull a higher gear, my fuel economy drops.
I’ve had three eye-opening experiences over the years that have stuck in my mind.
In 1969 I went from Los Angeles to New York on a Harley Davidson Sportster. I had exchanged the stock 20-tooth front sprocket for a 23-tooth thinking it would improve my fuel economy. That’s 15% higher gearing, which should give me an additional 15% in mpg. Right? Well, it didn’t work out to be the case.
In Arkansas I ran into a stretch of country road with a 45 mph speed limit. I decided to run third gear (the bike was a 4-speed) to avoid lugging the motor. I ran third gear for about 50 miles. I was surprised when I didn’t go on reserve until after having traveled at least as far as I usually did. The third gear running hadn’t decreased my mpg. The lighter throttle application required by the lower gear evidently evened things out.
Around 1980 in a 6-cylinder Chevrolet with a 3-speed manual transmission I was taking the family up a 10,000 foot mountain. I had installed a driving computer that told me my mpg in real time. At about 30 mph around 8,000 feet above sea level the car could pull the grade in top gear. I shifted down into second gear to see what would happen. To my surprise my mpg increased by about 2 mpg.
The third instance was this past summer. On a Suzuki GS 450 I took a remote road that ended up having a section of 20 miles of rough washboard dirt. I ran second and third gear for that 20 miles to avoid vibrating out my headlight, etc. When I filled up at the next town some 50 miles away, I had achieved 74 mpg! This is a bike that usually gets around 60 mpg.
This confirmed in my mind that running the lower gears is offset by the light throttle (except in the most extreme of situations).
So when going up any but the most gradual of grades on the Bandit I shift down a gear or even two, depending on my speed, which increases the rpm, but allows less throttle. Sixth gear is actually an overdrive and works best on level ground and downhill. Witness Dale Walker’s Bandit speed run. He never gets into top gear. He tops out at about 9,000 rpm in 5th gear. Shifting into 6th at top speed would just slow him down and use more fuel.
In city traffic I seem to get better fuel economy using lighter throttle and letting the motor run up to a little higher rpm as I get up to speed instead of shifting up to the next gear early and “torqueing it on.”
Under steady running I generally keep the motor around 2,500 to 4,000 rpm.
These are the things that work for me. If they help someone else, that’s what this forum is all about.