when do you shift gears?

[Chordeiles]

My 95 NH 750 owners manual has this to say...

Shifting up-
1st>2nd: 12 mph
2nd>3rd: 19 mph
3rd>4th: 25 mph
4th>5th: 31 mph

Shifting down-
5th>4th: 22 mph
4th>3rd: 16 mph

[n5tbu]

My 95 NH 750 owners manual has this to say...

Shifting up-
1st>2nd: 12 mph
2nd>3rd: 19 mph
3rd>4th: 25 mph
4th>5th: 31 mph

Shifting down-
5th>4th: 22 mph
4th>3rd: 16 mph

Using this site:
http://www.gearingcommander.com/

I came up with this:
Shifting up-
1st>2nd: 12 mph,2550rpm would be 13.9mph
2nd>3rd: 19 mph,2550rpm would be 20.2
3rd>4th: 25 mph,2550rpm would be 26.9
4th>5th: 31 mph,2550rpm would be 35.5
Man,I thought I was short shifting! Think I'll try it next trip to see if I can improve my mpg's even more.
I could NOT drive like that on a typical short ride,I'd get bored fast!
mod

[talespin]

That works out to shifting at 20, 30, 40, and 50 kph (just in case anybody was interested, or wondered where those odd shift points came from).

[k45]

My tach doesn't work either but according to those figures above, I probably shift at between 2500 and 3000 rpm.  

I just CANNOT bring myself to rev up an engine to high rpms, it's not in my blood.   I'm sure I could go higher than I do, but.....

As for "how far on a tank of gas", I just went 208 miles without hitting reserve and took just a little under 4 gallons.  I guess I was hitting it pretty hard that day and my mileage suffered :)

Ken

[hppants]

IMO occasionally, the bike needs to be reved up to get the combustion chamber temperatures up and attempt to burn off any carbon-based deposits.  Heat treated carbon is harder than just about any metal, and over time, this can cause pre-mature wear on the rings, pistons, valvetrain, etc.  I think this is more relevant with a carbeurated engine, as fuel injectors do a better job of cutting of the fuel in response to throttle changes, etc.

Plus, every once in a while, it's REALLY fun. 

[LOKi]

My tach doesn't work either but according to those figures above, I probably shift at between 2500 and 3000 rpm.  

I just CANNOT bring myself to rev up an engine to high rpms, it's not in my blood.   I'm sure I could go higher than I do, but.....

So you never go over 50mph?   Pants is right. These engines are made to run at higher RPM's. If they are not ran into those higher RPM ranges then carbon build up will start to rob you of power and wear out the engine even faster. That's like getting a Ferrari and driving it like an economy car. Or running a F-1 car below 80mph. Anything below 80 for any extended period of time will over heat the car. The nighthawk can do 60mph in second. And it was designed to do so. Do you think they would gear it like that if they did not intend on using that higher RPM power? Small engines get their high horse power from the fact that they can turn at higher and higher RPM's. The NH actually turns pretty slow for a motorcycle. The red line on a 650 GSXR is 15,000 and they put out and 108ph at 13,000rpm. That is a smaller engine putting out much more HP than our 750's because they can turn so much faster. Hell the NH doesn't even produce enough power to charge the battery until 2,000 RPM.  

As for "how far on a tank of gas", I just went 208 miles without hitting reserve and took just a little under 4 gallons.  I guess I was hitting it pretty hard that day and my mileage suffered :)

Sorry you where not "hitting it pretty hard" there buddy.   I don't get 52mph on my best worst days. Hitting it pretty hard can drop my mpg down into the low 30's and being good I'll be in the high 30's. When I was riding dirt a lot in lower RPM's I did get in the upper 40's once but I was not running the RPM's up much at all.

[k45]

Yes, I do get it all the way up to 65 in top gear sometimes. I might have even hit 70 the other day.  I'm  just not accustomed to revving it in lower gears.   After all, Honda says to upshift to 5th at 31 mph ;-)

Okay, I'll try some faster revs but I know it will be hard.   This isn't one of those fast revving hot rod sport bikes ;-)

Ken

[LOKi]

After all, Honda says to up-shift to 5th at 31 mph

Those are minimums. Anything lower than that and your lugging the engine. Being on the edge one way or another is not good. That's like saying well the red line is 8,500 so I shift there. Try shifting into 5th at 29mph and open up the throttle and see what happens. It should sound awful. Lots of knocking and absolutely no power. If you never twist the throttle then you won't hear it but then whats to point?

This isn't one of those fast revving hot rod sport bikes ;-)

She is faster than you think.

[Laminar]

Sorry you where not "hitting it pretty hard" there buddy. 

You didn't sense the sarcasm?

[LOKi]

Sorry you where not "hitting it pretty hard" there buddy. 

You didn't sense the sarcasm?

yea but he didn't hit the sarcasm button.

[martian]

k45 - I bet I get worse mileage on my 450 than you do on your 750.  Of course I try to ride my 450 like I ride my V65...

[In other news the new Vmax has a programmable shift light]

[k45]

k45 - I bet I get worse mileage on my 450 than you do on your 750.

Typically I get 54-56 mpg.   It never sees an Interstate highway, the nearest one is an hour and a half away so most of my riding is 40-60 mph. 

The local roads around here do not have any traffic enforcement (other than what's natural).   It's hard to go faster than the speed limit on most of the roads here.   We did see one pickup truck last spring that tried it:  he ended up down in the creek, ten feet below the road.

[LOKi]

k45 - I bet I get worse mileage on my 450 than you do on your 750.

Typically I get 54-56 mpg.   It never sees an Interstate highway, the nearest one is an hour and a half away so most of my riding is 40-60 mph. 

The local roads around here do not have any traffic enforcement (other than what's natural).   It's hard to go faster than the speed limit on most of the roads here.   We did see one pickup truck last spring that tried it:  he ended up down in the creek, ten feet below the road.

I'm confused.  Don't you live in Ohio? 

[k45]

I'm confused.  Don't you live in Ohio? 

I'm in rural southern Ohio, down along the river.   The nearest Interstate is down in Kentucky.

[Poligrafovich]

Here's my $.02 worth. Money cheerfully refunded if not satisfied.

Some things are simply bad for the engine. Too low an RPM with too much throttle ("lugging") results in improper combustion, typically heard as a knock, ping or rattle. This can cause various forms of damage. Too high an RPM results in loud noises and/or pieces of metal flying out of the engine. This is also bad.

Within the large remaining range, what shift points are optimal depends on what you're trying to do. For best acceleration, the answer is straightforward. Using a torque curve for your engine, graph the road force (engine torque X overall drive ratio) vs speed for each gear. Stay in the gear with the highest road force at whatever speed you're going. That's it. See http://www.tamon.org/wheel_calc/formula.html for a good example.

Maximizing engine efficiency is simple but not terribly useful. Maximizing fuel economy is related and more useful, but more complicated. The key to both is Brake Specific Fuel Consumption (BSFC), the relationship between engine speed, power output, and fuel use. BSFC has some general characteristics that hold across different size engines of similar type. http://www.autospeed.com/cms/A_110216/article.html has a good explanation of these.

Power for a given amount of fuel is greatest with wide open throttle (honest, officer, I was just being energy-efficient) at some particular RPM. At lower RPM heat dissipation lowers combustion chamber temperature and reduces efficiency; at higher RPM friction losses eat more power. Unlike the HP peak, an engine's efficiency "sweet spot" tends toward the lower end of the engine's useful range. So the most fuel/power efficient gear is one where you're running WOT and at constant and optimal RPM. Not often a useful optimization for a motorcycle since you don't get to pick the road speed.

At other than full throttle, fuel/power ratio gets worse rapidly, and the further you are off the optimal RPM, the worse the story gets. In particular, the fuel efficiency really starts to suck when you're running part throttle at high RPM. Look at the bottom graph in the "When You Close the Throttle" chart for this. While it is not possible to know the exact RPM of greatest efficiency without data for the particular engine, the basic relationships hold: there's a bigger penalty for running above optimal than below. The takeaway here is that winding it out to high RPM makes sense only when you're hard on the throttle. Otherwise, shift low in the RPM range for better mileage.

BSFC also explains why those 250s get such good mileage: they spend a lot more time with the throttle further open and hence closer to their point of optimal efficiency. All other things being equal, the most efficient engine is one that's exactly big enough for what you need it to do.

[LOKi]

^^^

so your saying I need a 1000cc bike.....check! 

[Dr. Psycho]

When do I shift hmmm well let's see, sometimes around 4-5000, most times around 7500  I love the way this bike pulls over 7000. When I want range I ride the Venture(1200) which also pulls hard but not like the 700.

I wish I lived where there was no traffic enforcement, I would ride it like I stole it .