The New And Improved Unofficial R65 Forum V2

Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: scottyintex on November 29, 2010, 10:43:27 PM

Title: best RPM's for a R65
Post by: scottyintex on November 29, 2010, 10:43:27 PM
I was talking with a R65 owner...and he said the most idea RPM was over 5000..about 5600 for running down the highway. That a R65 needs high RPM’s  because of it short stoke. I always thought the “sweet spot” was between 4000 to 5000. In truth I never use the tach much but go mostly by ear. When the engine reaches high revs ....I shift. But he has me wondering if I am not shifting too soon. He said he was surprised I used 5th gear much ....running with my sidecar. I never run in 4th on the highway unless I am climbing a steep hill. I run between 60mph and 70 all the time in 5th with a little bit of throttle left.. My sidecar is a light weight one..165 pounds empty. Ok, as I see it this guy is just full of it. But I would like to hear from some of the more experienced riders out there.
Title: Re: best RPM's for a R65
Post by: unibober on November 29, 2010, 11:19:33 PM
I agree with you. I keep my highway tach around 4300-4800. My ears play the biggest role in gear selection. Lots of "experts" floating around.
Title: Re: best RPM's for a R65
Post by: Barry on November 30, 2010, 07:27:52 AM
Quote
I always thought the “sweet spot” was between 4000 to 5000.

I agree as anything over 5000 gets me into a bit of vibration.

Peak torque revs are higher still though which is where your friend may be coming from.
Title: Re: best RPM's for a R65
Post by: nhmaf on November 30, 2010, 08:26:21 AM
If I'm on an interstate and conditions permit, I've found that ~ 5200 RPM in top gear is pretty sweet, though it is just a bit above the usual speed limit.. but usually I also like running in the 4K - 5K zone, though there is a spot of annoying vibration around 4700-5000 that I try to avoid for long periods.
Title: Re: best RPM's for a R65
Post by: darrylri on November 30, 2010, 08:55:58 AM
Depends on what you're doing with the bike.  Cruising down the slab?  Sure, get it into a higher gear and save gas.  Sporting around on the back roads?  Rev it higher and use the throttle to control your corner entry speed.  You can surprise a lot of people on bigger bikes.
Title: Re: best RPM's for a R65
Post by: Lucky_Lou on November 30, 2010, 10:52:45 AM
I cruise at 4500 to 5000 rpm 65/75 the engine is sweet at that i avoid 4000 as thats were my vibration zone is +/- 100 i did do the science test on the final drive and got 15mph per 1000revs with no vibration anywhere else all the way up to the stratosphere.
Lou
Title: Re: best RPM's for a R65
Post by: Ed Miller on November 30, 2010, 11:19:23 AM
Mine is steady, smooth, and quiet at around 4,000 rpms, or anthing 5,000 on up to red line.  On an interstate, with no cops around, I cruise at 6 grand.  The bike seems really happy there.

Title: Re: best RPM's for a R65
Post by: suecanada on December 01, 2010, 12:07:46 PM
I can cruise on the interstates over 5000 but normally on secondary roads do what nhmaf does and keep it away from the mid-4500-4800 range where the small vibration is. I am always quite amazed how happy the engine sounds and performs over 5000! The torque range max. is a really good point....hits a sweet spot over 5000's for these engines. I just don't feel that comfortable going over 5000-5500! I will ask LRB his feelings on the matter!
Title: Re: best RPM's for a R65
Post by: Semper Gumby on December 02, 2010, 08:20:15 AM
About 5200 rpms for my 1980 works just fine.  I've *heard* that when you spend extended amounts of time near 6000 rpm the bike starts having reliability problems.

Depending on what I'm doing I will shift anywhere from 3000 to 6000 rpm.

First thing in the morning coming out of the driveway warming up its 3K.  If I'm passing a bunch of cars its 6K.   8-)
Title: Re: best RPM's for a R65
Post by: Motu on December 03, 2010, 12:46:26 AM
The mono makes max torque at 3,500rpm,and has a higher final drive than the old R65.Anywhere between 4,000 and 5,000rpm is a happy place for me.The only time I can ride at over 5,000rpm in NZ is on main highways,and it's too easy to loose your license doing that.
Title: Re: best RPM's for a R65
Post by: trolle on December 03, 2010, 03:17:10 AM
Quote
On an interstate, with no cops around, I cruise at 6 grand
6000 rpm correspond to the highest allowed speed on the Danish motorways and I find that the interval between 6 and 6.5 K is very smooth and leaves you enough power to speed away from a potential dangerous situation. The fact that consumption rises with at least 20% when the speed increases from 75 to 85 mph is something you have to live with :-)

greetings from a cold and white north, winter came very early this year!
(https://bmwr65.org/smf/proxy.php?request=http%3A%2F%2Flh5.ggpht.com%2F_IG1zYdpfI5U%2FTPi1aU3zJcI%2FAAAAAAAAP4I%2FpQrDbwXEn-4%2F03122010.jpg&hash=61ee7b698a490b43c74c59915c0bb277c66d2e1d)
Title: Re: best RPM's for a R65
Post by: Tv on December 07, 2010, 04:32:38 AM
The general open road speed limit here is 100kph and depending on the gradient of the road the bike runs around 5000 revs to 100/110k. I generally sit somewhere between 4k & 5k and my vibrator starts around 4.5k to 4.8k not that I'm fussed.  I must try sitting on 6k for a while and see how it goes.  I'm always apprehensive to rev the crap out of it in case it falls to bits.