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never looked at 70mph. I know at 90mph I am about 7k rpm's.
 

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Jack of all trades
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I'm at about 5k also. But I just keep mine at about 5.5k and go with the flow
 

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Right around 5k is normal at 70mph.
 

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Concert connoisseur
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5k, I think our bikes love it!
 

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Discussion Starter #6
Anyone with extensive experience know what effect that has on gas mileage? When does it start to get dangerous for the engine?
 

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Linkmeister Supreme
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I worked out the actual speed from the gear ratios a while back.
In 5th gear the vn750 true speed is 14.5 mph/1k rpm
so 5k rpm = 72.5 mph
6k rpm = 87 mph.
7k rpm = 101.5 mph

Keep in mind the speedo with the stock 100/90-19 front tire reads about 10% higher.

Running at high rpm will suck back a lot more fuel, but it has been reported that this little v-twin really wakes up at 7k rpm. I can`t verify that as I never reach those engine speeds.
 

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Git-R-Done!
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I'm pretty sure that's about what my bike runs at around 70mph. As far as gas mileage, I don't really think it's a big concern at only 5K rpm. I say "only" because our bikes don't even redline til much higher (can't remember what it is right offhand, but I'm thinking around 9K or so...?)

Keep in mind that a v-twin motorcycle can run at much higher revs than a typical v8 for example. And IMHO, these engines need to be run - like REALLY run - once in awhile to keep them at their peak performance. I have found in my experience that bogging these engines down by only running them around 4K rpm all the time causes carbon deposits to form and the cylinders to "gunk up" and actually decreases performance. So I wouldn't worry about the 5000 rpm. If you consider the fact that the normal idle for these machines is 1100 rpm, and compare that to the 4 or 500 most v8's are, that will give you an idea of what I am talking about.

Happy - and safe - riding!

AZ Kev
 

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Keep in mind that a v-twin motorcycle can run at much higher revs than a typical v8 for example. And IMHO, these engines need to be run - like REALLY run - once in awhile to keep them at their peak performance.
I think it depends more on piston size and valve design. A 750cc V8 could concievably run a 13,000 redline. Inline fours usually make more power at higher revs.. V twins are noted for making alot of torque at lower rpms compared to other layouts.

The only reason the Vulcan 750 revs well is it uses a cam chain to run the valves...and it is only 750cc. Other V twins with push rods and larger displacement tend to have lower redlines and are usually tuned to make their power mid range or lower..


Not correcting here, just informing......

KM
 

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Redline is 8,500 RPM's I believe. Mine don't really start to run till I hit around 6K or better, but not for any really extended periods of time. I'll take mine out on occasion and wind her up to keep her cleaned out. And yes these styles of engines with the cam chains can run at a higher RPM then push rod type because the push rod type will float the valves at higher revs.
 

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Linkmeister Supreme
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The vn750 redlines at 8,500 rpm.
IF you can reach it, the bike should be travelling ~123 mph.
(Probably get half the range at twice normal speeds.) :)

My bike won`t develop those revs in 5th gear with a large windshield and #300 of rider.
 

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Anyone with extensive experience know what effect that has on gas mileage? When does it start to get dangerous for the engine?
I just ck'd my milage when I filled up. 33mpg! That sucks! My SE HD got about 40 when just puttin. Course duel carbs may have something to do with it?
 

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I just ck'd my milage when I filled up. 33mpg! That sucks! My SE HD got about 40 when just puttin. Course duel carbs may have something to do with it?
Yes, but think how much gas you can buy for your Vulcan with what you saved not buying another Harley.

And I do not think someone has a gun to your head making you twist the throttle that hard while you ride it.


KM
 

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Mine is just a tad over 70 at 5k. We both enjoy it a little higher than that. ;)
 

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I just ck'd my milage when I filled up. 33mpg! That sucks! My SE HD got about 40 when just puttin. Course duel carbs may have something to do with it?
My ride to and from work puts me on both streets and freeways. 70 is not a uncommon speed (for everyone) in Dallas traffic. I still get just over 40mpg. Usually fill up when it's at 110 miles, but have gone further when I've forgot to look. Usually takes just over 2.5 gallons.
 
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