[aftermath4788]

I have been thinking here lately about how does the engine size affect RPMS at 60mph. I want people to post up what their bikes rev at when doing 60 and explain the bike. Year, Engine CC, Make, Model. ETC If your bike is stock, please state it and if its not stock, state the upgrades that make the bike rev higher or lower than normal. I just want to tickle my fansy about engine revs and different bikes. Ill start off with mine.

2006 Ninja 2006 STOCK 60mph=7300 rpm.

1991 Ninja ZX11C Upgraded engine, jet kit, big bore kit. stock sprockets. 60mph=3700rpm

 

[Plato]

Hmmm, assuming you just mean the indicated speed (rather than adjusted for common error) my new to me Ninja 250 seems to be around 7k rpm when doing about 60mph -takes another 2k to hold around 70mph.

For another reference from the big Vulcans -my Nomad is lugging in top gear if I just do an indicated 60mph the stats show its at around 2.5k rpm at that slow pace. Most 1600 Vulcan riders learn quickly not to even go to 5th gear until the speedo climbs past 70mph... :wink:

 

[Emc-Icon]

03 636 muzzy pipe, K&N, stock gearing (as far as i know) 60mph = 5k rpm's in top gear..

 

[love2ride]

2006 Ninja 250
Gearing changed from stock 14/45 to 15/42
Kenda K671 tires front is 100/90-16.

60 mph : 6500 RPM's, the speedo seems to be pretty accurate according to the Radar trailers on the side of the road(I love making them blink, and then the blue and red lights on the trailer flash):evil:

This is pretty cool for Ninja 250's Ninja 250 Speed Calculator

 

[aftermath4788]

wow, that link it cool. it is amazing how unaccurate the speedos are. i wonder why that is. is it that the factory isnt calibrating them perfectly or just the simple fact that its a mechanical thing that makes it off a bit. are digital speedos accurate? lol i do 65mph indicated on my 250 to work everyday and was wondering why it would take me longer on that bike to get to work versus my car or other bike doing the same speed. weird.

 

[love2ride]

Ive heard it had something to do with letting you think you are going faster than you really are. Not sure if digital speedos are more accurate. Every bike I've owned had analogs.

 

[adamp961]

doesn't rpm's depend more on the engine stroke??

 

[aftermath4788]

rpm depends on revolution. which simply means everytime the piston goes from top dead center to bottom dead center and back to top it is on revolution IE 2 strokes. so no it doesnt depend on strokes.

 

[adamp961]

I understand what rpm's are, but what i am saying is just because the engine size is bigger or smaller doesn't always mean it will have a higher or lower rpm. Example most a v-twin engines with a longer stroke will not run the same rpm's as a in line 4 at the same highway speed

 

[Squidly]

bone stock '07 Z1k

60mph= 4100rpm

 

[ervins]

80+ mph around 5k+ on a 10R. Depends on the gear for me...That is on 5th...I will need to check later.

 

[Emc-Icon]

I understand what rpm's are, but what i am saying is just because the engine size is bigger or smaller doesn't always mean it will have a higher or lower rpm. Example most a v-twin engines with a longer stroke will not run the same rpm's as a in line 4 at the same highway speed

its ALL about gearing..
my guess is that the manufacturers know that most racers will change sprockets for each track, so they picked an "all around" gearing ratio to work everywhere..

That applies to Supersports mind you.. the cruisers will rev much lower at freeway speeds.

 

[JimmyD]

its ALL about gearing..
my guess is that the manufacturers know that most racers will change sprockets for each track, so they picked an "all around" gearing ratio to work everywhere..

That applies to Supersports mind you.. the cruisers will rev much lower at freeway speeds.

And the reason cruisers rev lower is because v-twins have longer strokes. Japanese-designed vtwins are built differently and rev higher than american-designed v-twins.

I mean, there's a ton of other variables like valvetrain, gearing, crankpins, etc. But this is the reason that an american v-8 redlines at 6k whereas an Italian V8 can redline at 12k. They generally have shorter stroke and the valvetrain can spin faster because of it. If I'm recalling correctly.

As for your question, my EX runs at 140 kph (88mph) at 7k with stock gearing (16/41). In 6th each 1000rpm = 20 kph.

My friend's CBR600f4 ran at 140/7000rpm as well. But he has way more revs than the EX.