High RPM 70 MPH cruising speed

33688 Views 26 Replies 14 Participants Last post by PugslyCat, 9 mo ago

chbart

Discussion Starter · Oct 1, 2015

I noticed my Street 750 rides just a little high on RPM's once I level off at a 70 MPH cruising speed. Since this is the typical speed limit on interstate highways around me, I kinda wish it was a little lower in RPM's like it feels around 55-60 MPH. I figured with that 6th gear and all, this would not be an issue, but it is. I have a TBR slip on muffler, love the sound, esp at the 55-60 MPH speed, (deeper throatier) vs. 70. Wondering if any customization can be done to a smaller 6th gear to accommodate a lower RPM cruising speed without losing anything (power, etc). Not sure if anyone knows, Or also feels what I'm talking about.

1 - 20 of 27 Posts

jsa3107

· #2 · Oct 1, 2015

My wife got her new 2016 750 today
i rode it home
I went on Rte 95 and ran it at 65 and then 70
I didn’t notice the RPMs being to high (no tach but felt fine)
The wind in the chest was tough (needs a windshield)
But the bike rode fine at 65-70

Happy riding...

Crusty Primate

· #3 · Oct 1, 2015

Honestly, I don't think the RPM's are really winding up until you're past 80. It seems to want to peter out past 90 and slowly makes its way up to 105.

I don't make this a regular practice, but on the occasions I've had a long, empty stretch of road and curiosity, I've given it a shot.

Maybe try getting to 70 in 5th gear and then shifting up to 6th and see if there's a noticeable difference. I've noticed that depending on my shifting pattern (short shifting vs winding the gears out) that the RPMs will be lower at speed in 6th if I actually work my way up to top end starting from 2nd gear onwards.

Reactions: 1

oandy

· #4 · Oct 1, 2015

Well if you wind out the gears you will hit 80 in third gear before having to go to 4th, I really havent attempted to peg out the speedo yet but I have gotten it to 100 really quickly

Reactions: 1

oandy

· #5 · Oct 1, 2015

If I get a phone holder I will see what rpms are at 70mph

Reactions: 1

Rock270

· #6 · Oct 2, 2015

these water cooled engines do rev higher than most old school stock v twins

if I remember right, it red lines at 8500 rpm.
that's pretty high for a v twin.

these motors don't like to be lugged like a large v twin air cooled motor. the power band is fairly consistent across the rpm range on these.

maybe it'll take a while to get used to the difference.

Reactions: 1

Crusty Primate

· #7 · Oct 2, 2015

Doesn't the rev limiter kick in somewhere around 8-8100 though? Might depend on mods and fuel mapping. I'm still running stock and would get a nasty surprise when trying to take off from a toll booth and wringing the throttle. About the only time I'd ever wished for a tach.

You're right, you can do 80 in 4th.

Rock270

· #8 · Oct 2, 2015

Crusty Primate said:
Doesn't the rev limiter kick in somewhere around 8-8100 though? Might depend on mods and fuel mapping. I'm still running stock and would get a nasty surprise when trying to take off from a toll booth and wringing the throttle. About the only time I'd ever wished for a tach.

You're right, you can do 80 in 4th.

yeah, I don't know at what rpm's the limiter kicks in, but I'm sure some one here knows.....I have hit the limiter on mine a few times momentarily.

one thing I do know is that from a red light taking off pretty hard and high revving the engine through the gears it doesn't take long to hit 100 mph >

Reactions: 1

chbart

Discussion Starter · #9 · Oct 2, 2015

Yeah, I have no problem getting to 80+ speeds and all, it just seemed to be a little "high pitched" when I wanted to "level off" & "cruise" at a steady 70 mph, where I wish it was a little lower in rpm. In credibility to what everyone is saying here, your absolutely right - once at that leveled off 70 mph, when i get on it from there, whether 5th or 6th, it takes off no problem even getting up to 100. It could be the perfect receipt "pitch" (70 mph speed, rpm, with helmet covering my ears, with my TBR slip-on) - it could just be my slip-on, the way its producing sound, maybe a higher pitched sound on 70 mph leveling off the throttle.... as the more I think about it, once I get on it again from 70, the sound drops a little deeper. Oh - and I can tell you I found rev limiter at 90 mph in 5th..

Rock270

· #10 · Oct 3, 2015

the loose cannon I have on mine also has a higher pitch to the sound at higher speed freeway riding.

.... it may just be the nature of a water cooled engine vs a large air cooled v twin.

Rock270

· #11 · Oct 3, 2015

chbart said:
Yeah, I have no problem getting to 80+ speeds and all, it just seemed to be a little "high pitched" when I wanted to "level off" & "cruise" at a steady 70 mph, where I wish it was a little lower in rpm. In credibility to what everyone is saying here, your absolutely right - once at that leveled off 70 mph, when i get on it from there, whether 5th or 6th, it takes off no problem even getting up to 100. It could be the perfect receipt "pitch" (70 mph speed, rpm, with helmet covering my ears, with my TBR slip-on) - it could just be my slip-on, the way its producing sound, maybe a higher pitched sound on 70 mph leveling off the throttle.... as the more I think about it, once I get on it again from 70, the sound drops a little deeper. Oh - and I can tell you I found rev limiter at 90 mph in 5th..

if you could change out the drive belt sprockets that would change the gearing ratio to drop the rpms at freeway speeds but it may also ruin the low end quickness too.

I've seen on project bikes where they changed over to a chain drive setup, not that I'd like that.

AYEDEE

· #12 · Oct 3, 2015

Rock270 said:
the loose cannon I have on mine also has a higher pitch to the sound at higher speed freeway riding.

.... it may just be the nature of a water cooled engine vs a large air cooled v twin.

The engine note will be deeper when there is load on it. When you are closer to your cruising speed or when your engine reaches higher RPM, the engine is mostly relieved of the load and momentum plays a big part in keeping the bike moving with ease. Therefore, the engine note is higher pitched. I'm sure you will get used to it and begin liking it.

Reactions: 2

KiwiHOG

· #13 · Oct 4, 2015

If I can remember, i'll start the log on my PowerVision , can record up to about 6 items, i.e. Speed, RPM, Temp, Barometric Pressure, Gear....all in an Excel spread sheet

You guys should really consider one if these iff you are looking for this kind of info....I am an INFO JUNKIE....so it's awesome!!!

I have complete records of the timing, knock , speed, rpm, VE, AFR....everything!!!

R

Reactions: 3

Tucsonmax1

· #14 · Oct 4, 2015

That's a bit out of my price range at the moment. Still trying to save up for Essentials. Saddle bags and Luggage rack. Then exhaust. And the fuel controller to go with.

Reactions: 2

KiwiHOG

· #15 · Oct 5, 2015

Tucsonmax1 said:
That's a bit out of my price range at the moment. Still trying to save up for Essentials. Saddle bags and Luggage rack. Then exhaust. And the fuel controller to go with.

I'm riding it to work tomorrow, i'll do a log run and drop the CSV here.....don't expect 70mph - freeway speed is 60mph.....

I'll run SPEED, RPM, TEMP and GEAR

Ray

chbart

Discussion Starter · #16 · Oct 6, 2015

KiwiHOG said:
I'm riding it to work tomorrow, i'll do a log run and drop the CSV here.....don't expect 70mph - freeway speed is 60mph.....

I'll run SPEED, RPM, TEMP and GEAR

Ray

I would love to hear what the RPMs are!!..the other stuff would be a bonus...btw KiwiHOG, sent you a message on the PV..curious of your thoughts

Reactions: 1

mike28w

· #17 · Oct 16, 2015

My 2 cents.... I installed a fairly cheap digital tach yesterday. Bought it from Ebay or Amazon for ~ $50 bucks. Double stick tape and a wire that wraps around the spark plug wire. Looks like it's made for off road bikes.

The installation manual stated that the RPMs might read half of the real RPMs and if that happens , I can make an adjustment. So I went riding today and got these numbers:

Cold idle ~ 825 rpm
Warm idle ~ 600 rpm
65 mph in 6th gear ~ 2100 rpm

Hmmmm.....now I'm at a loss to know if this is the correct RPM or if in reality , it's double these numbers.....Any ideas, opinions or suggestions ??

Thanks, mike (Street 750)

Tucsonmax1

· #18 · Oct 17, 2015 (Edited)

The Idle Speed is around 1200 RPM. Your Tach is reading 1/2.

mike28w

· #19 · Oct 17, 2015

Thanks a bunch !! mike

KiwiHOG

· #20 · Oct 17, 2015

Warm up idle is 1400-1500rpm

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