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TECHNICAL MOTOBRICK WRENCHING In Remembrance of Inge K. => The Motobrick Workshop => Topic started by: beemrdon on January 31, 2017, 12:54:58 AM

Title: Is a sustained 7,000 RPM too much? How about 8,ooo?
Post by: beemrdon on January 31, 2017, 12:54:58 AM
I now live in Southern Ethiopia. Some of the interstates out of town are pretty empty.
That being said, the other day I was cruising on a beautiful sunny day on a smooth interstate hwy and before I knew it I was going 10 mph. Not a big deal as the bike was steady and felt well planted. Well, just for the hell of it I then pushed it up to 11. OK that's good. I eventually got it up to 25 and held steady.
My question is...Will the engine run at this RPM without blowing a seal or something? I'm sure folks over in the Fatherland have wrung these bikes out on the Autobahn routinely.
Thanks
Title: Re: Is a sustained 7,000 RPM too much?
Post by: Motorhobo on January 31, 2017, 07:07:35 AM
I got it to sustained 115 only once and it was cranking pretty good...I had the feeling the bike was getting used to it and could go all day at that. Me, not so much...backed off after about 10 minutes when the Californian in the Lexus I was following across West Texas got busted.
Title: Re: Is a sustained 7,000 RPM too much?
Post by: F14CRAZY on January 31, 2017, 08:36:36 AM
I read somewhere that motobricks were benchmarked to do 300 hours at full throttle, full load at redline, if that helps.
Title: Re: Is a sustained 7,000 RPM too much?
Post by: Chaos on January 31, 2017, 08:44:51 AM
wish I was in an area where I could hold a century or more.  you may be shortening your engines lifespan from 300,000 to 290,000 miles but it's worth it. 
Title: Re: Is a sustained 7,000 RPM too much?
Post by: The Mighty Gryphon on January 31, 2017, 09:47:52 AM
I read somewhere that factory quality assurance tested random production motors at redline for 24 hours.  That is about the equivalent of running from San Diego to Jacksonville in 24 hours.  And that is on an engine that hasn't been broken in!

Personal experience was to run my K75RT one up with a full touring load at 100mph for about an hour in west Kansas.  I know that I can run at 75-85mph non-stop for 24 hours and she will love it.  80k on that bike now and mechanically it is still like new. 

Brick is a good name for these engines.
Title: Re: Is a sustained 7,000 RPM too much?
Post by: Snowman on February 03, 2017, 03:30:44 PM
6000-7000rpm is a sweet spot for my LT, really smooth, so I cruise at that. SD & ND gets some nice empty highways.
Title: Re: Is a sustained 7,000 RPM too much?
Post by: beemrdon on February 03, 2017, 08:05:38 PM
OK, so what about 8,000 rpm?









Title: Re: Is a sustained 7,000 RPM too much? How about 8,ooo?
Post by: johnny on February 03, 2017, 08:18:02 PM
greetings...

to unleash the monster within the motobrick... shift at the red line... 1st to 2nd to 3rd to 4th... then look at the speedometer...

3k 4k 5k 6k on the tach... f that... 7k and higher... just prior to the rev limiter... riding on the redline... thats where the fun is... why wait for 5th...

j o
Title: Re: Is a sustained 7,000 RPM too much? How about 8,ooo?
Post by: mystic red on February 03, 2017, 08:29:30 PM
Things happen pretty quick when you twist up a 1100 up to redline in 2nd.
Title: Re: Is a sustained 7,000 RPM too much? How about 8,ooo?
Post by: johnny on February 03, 2017, 08:31:41 PM
greetings...

thats right red... it aint no lifestyle droner or soulless kawacker versys... dont ride it like one...

i seldom ride in 5th cause i wants instantaneous power... thats 7k and above...

the rev limiter aints gonna let you grenade it in 5th...

j o
Title: Re: Is a sustained 7,000 RPM too much? How about 8,ooo?
Post by: The Mighty Gryphon on February 04, 2017, 12:09:40 AM
RPM's is something you just get used to.  I know when I got my first brick it spent a lot of time lugging around at 3 grand in 5th.  Spending some time on the interstate at 85+ eventually immunized me to high engine speeds, and now I find myself getting on the expressway on my commute and doing 75mph in 4th without realizing it.

These are definitely European engines that are built to rev.  Definitely not like the big v-twins that fire 6 or 7 times a mile.  The fact that they have a pretty wide power band and pull well from just off idle is just a nice bonus.
Title: Re: Is a sustained 7,000 RPM too much? How about 8,ooo?
Post by: Chaos on February 04, 2017, 01:38:29 AM
RPM's is something you just get used to.  Definitely not like the big v-twins that fire 6 or 7 times a mile.  .

hahaha.  Not like a Ninja 250 with it's sweet spot around 12,000 rpm either!  Surprisingly fun but felt like a big hornet's nest between my legs,
Title: Re: Is a sustained 7,000 RPM too much? How about 8,ooo?
Post by: Motorhobo on February 04, 2017, 09:22:49 AM
Where I live there aren't any twisties to speak of so running at 60mph in third is like flushing fuel down the toilet. So yeah... I use fifth, if there was a sixth I'd use that too.
Title: Re: Is a sustained 7,000 RPM too much? How about 8,ooo?
Post by: johnny on February 04, 2017, 09:42:55 AM
greetings...

im thinking a 24 hour posting ban is in order for a poster who suggests riding in 5th gear below 7k on the tach is anything more than motobrick curious...

j o
Title: Re: Is a sustained 7,000 RPM too much? How about 8,ooo?
Post by: drut on February 04, 2017, 02:40:20 PM
6K + is where the action is!Bike seems fine and certainly given me no problems with sustained high revs.I think they were built to cope with high speed long autobahn trips.As an aside I think the K10016v & especially K1100's were undergeared so the factory must not have feared them being revved to the limiter.
Title: Re: Is a sustained 7,000 RPM too much? How about 8,ooo?
Post by: Motorhobo on February 04, 2017, 03:13:34 PM
greetings...

im thinking a 24 hour posting ban is in order for a poster who suggests riding in 5th gear below 7k on the tach is anything more than motobrick curious...

j o

OK, so 7K brings it in 5th to what, 100mph? In my neck of the woods, 10 minutes of that and you've already passed through three states and not seen a curve yet. Dude -- I'm not gonna go 75 in 4th just because I can...I'd be stopping for fuel every 80 miles. Is that what Johnny does? How does that work... he drinks beer,  pisses no-corn ethyl, runs at 70 in 3rd, and has his catheter routed straight into the fuel tank?
Title: Re: Is a sustained 7,000 RPM too much? How about 8,ooo?
Post by: Elipten on February 04, 2017, 07:00:20 PM
LOL


Sent from my iPad using Tapatalk
Title: Re: Is a sustained 7,000 RPM too much? How about 8,ooo?
Post by: Chaos on February 04, 2017, 07:14:44 PM
LOL


Sent from my iPad using Tapatalk

+1   Rev envy!
Title: Re: Is a SUSTAINED 7,000 RPM too much? How about 8,ooo?
Post by: beemrdon on February 08, 2017, 12:34:16 AM
Guys.....My question is not 'how much can I rev it between shifts'. My question, again, is, How many revs per minute can this engine (and transmission?) SUSTAIN without blowing a whatever???


Title: Re: Is a sustained 7,000 RPM too much?
Post by: Motorhobo on February 08, 2017, 06:02:32 AM
I read somewhere that factory quality assurance tested random production motors at redline for 24 hours.  That is about the equivalent of running from San Diego to Jacksonville in 24 hours.  And that is on an engine that hasn't been broken in!


I think that was answered in the response above...although I'm not sure that could be documented beyond the vague 'I read somewhere' reference. For hard facts you'd probably have to be asking at BMW Motorrad not here.  I can't speak for your K1100 but I'd have no problem running my engine at sustained +7500rpm for as long as I needed to. But it's kind of a moot point because most people don't have a straightaway where they an do that in the real world without getting busted. If you know of one, keep it a secret because if you tell us where it is, you may have to wait in line.
Title: Re: Is a SUSTAINED 7,000 RPM too much? How about 8,ooo?
Post by: Chaos on February 08, 2017, 08:42:21 AM

So, can I sustain 8,000 RPMs traveling down the road, (the redline is 8,500) ?


yes
Title: Re: Is a sustained 7,000 RPM too much? How about 8,ooo?
Post by: The Mighty Gryphon on February 08, 2017, 08:51:41 AM
Motorhobo, the source for my statement about the 24 hour test was an old magazine article posted on the interweb that I ran across last summer about how they built the bricks.   The article had several photos from inside the factory and sounded a bit like those articles that are pretty much written by companies that buy a lot of advertising as an unpaid editorial/infomercial(I've written a few of them in my day). 

That's not to say that it's a steaming pile of B.S., but the durability of these engines and the desire of Motorad to continue their reputation for reliability kind of reinforces the validity in my mind.

Beemerdon, you gotta tell us where we can run at 140+mph for more than a couple miles at a time without winding up in the slammer going through Craig's List looking for a new bike, or does your transmission only work in 1st and 2nd gear?
Title: Re: Is a sustained 7,000 RPM too much? How about 8,ooo?
Post by: Motorhobo on February 08, 2017, 09:19:55 AM
Gryph -- if you say it, it's good as gold to me.

But you said it, and it seemed like Beemerdon either didn't see what you said or was looking for some kind of documentation. That's why I referred him to BMW Motorrad.


Title: Re: Is a sustained 7,000 RPM too much? How about 8,ooo?
Post by: The Mighty Gryphon on February 08, 2017, 09:36:34 AM
I just want to know of a 200+ mile stretch of road where I can run a constant 150mph without the risk of getting a couple nights lodging from the local law enforcement.

I can understand Beemerdon's reluctance to make the information public, but if he tips me off via PM I promise I will keep it to myself.

Title: Re: Is a sustained 7,000 RPM too much? How about 8,ooo?
Post by: The Mighty Gryphon on February 08, 2017, 09:58:51 AM
A little more background on the testing of engines.  I have sold equipment to GM back in the 80's and 90's which was used to test their engines, specifically the 3.8l V6 which, at the time, was considered by the engineers to be the best engine GM ever built. 

GM tests individual components such as cams and crankshaft assemblies for service life under various operating conditions(load, speed, temperature).  They also test complete engines to destruction to find weak points and to determine manufacturing tolerances.  Parts like cams and crankshafts have service lives of over 1,000,000 miles when operated with the specified oil change intervals at engine temperatures between 180 and 220F.  The internal parts of a production engine should be good for 350,000+ miles which in most cases is longer than the rest of the vehicle.

Based on what I have been told by the engineers I have worked with, I am not surprised that a K bike engine is capable of running at red line and full load for 24 hours.  I would be surprised if it wasn't.
Title: Re: Is a sustained 7,000 RPM too much? How about 8,ooo?
Post by: The Dude on February 08, 2017, 12:43:17 PM
You can add another 76 hours to those 24.From what I was told by BMW back in the '90s.They were then stripped down for inspection.
A modern engine regularly does 300 hours at full wack in QA testing.(Hyundai diesel).
Title: Re: Is a sustained 7,000 RPM too much? How about 8,ooo?
Post by: mg1 on February 10, 2017, 04:41:32 AM
Sounds like an "italian tune up".  A certain mechanic I know of was said to indulge in such a tune up, where a K had its fluids changed and then run out to a deserted stretch of country road and run at full throttle for 30 minutes or so then handed back to its owner.  It supposedly had the effect of decarbonising the motor (many K owners being very conservative in their riding style, leading to carbon build up and consequent rough running) and the unwitting owners thought it was great.  Not sure how much store to put by that story, but I do know that my wife bought a non-runner ex-Police K75RT at the auctions once upon a time.  It had been used for escort duty by the WA constabulary until its HES failed.  Once it was back on the road again, it didn't run happily for some months, until we took it on a long interstate trip at an - err- "brisk" pace and it eventually cleared its throat over 1000km or so.  Ran fine after that.  As other inmates have said on this forum, K bikes love to rev. Keep up the maintenance and let it rip.


Martin the other
in the bloody hot Riverina, Australia
Title: Re: Is a sustained 7,000 RPM too much? How about 8,ooo?
Post by: Motorhobo on February 10, 2017, 06:55:21 AM
Well, now that you've all put the fear in me I ran my bike at 80 in third for a half hour just to keep it happy. That's about the only way to get it to 7k rpm around here.

Title: Re: Is a sustained 7,000 RPM too much? How about 8,ooo?
Post by: Vespa no more on February 12, 2017, 05:30:55 AM
In Australia, the Northern Territory was (in)famous for an attempt at a cannonball run. A few fellas with all the gear ... came unstuck. Don't know what the speed limits are these days and it is a long ride there.


Finally got an opportunity to open up my K100 (has been off the road for some years) after getting around a convoy of sunday harley riders. It found another lung above 7000rpm and I backed off at 7500. Just made me want to see if 8000 + was on. But being grown up and mature haven't found the moment.


Am playing around with an ex-police K1100. Looking into the fuel injector holes and into the top of the throttle bodies there is plenty of grot - which adds credence to the comments earlier. Will need a good clean and sustained run... whenever that happens.



Title: Re: Is a sustained 7,000 RPM too much? How about 8,ooo?
Post by: beemrdon on February 12, 2017, 11:27:05 PM
The more I think about it, the more I feel that the only folks that really know are the engineers that designed this motor (and all of the other K...brick motors. They are probably retired by now (or worse).
I am not just concerned with the motor but all of the driveline parts.
As to where you can run at 8,000 RPM for more that a few miles, I'm going to tell you. North on 95 out of Las Vegas, about 20-25 miles up the road after you pass the prison. I went 125 there and could have gone faster but backed off because I was revving @7,000rpm and wasn't sure about the sustainability of this course of action on the drivetrain....after having run 100-110 for miles. The road is ultra smooth and straight only undulating somewhat and I felt entirely comfortable at 110+ and very little traffic.
Also, interstate 80 in Wyoming has a posted limit of 80 mph in places but many are going at least 10-15 mph over that and some are moving MUCH faster. :yow

 
Title: Re: Is a sustained 7,000 RPM too much? How about 8,ooo?
Post by: The Mighty Gryphon on February 13, 2017, 12:49:28 AM
I have done I-80 in Wyoming several times with my K75 and running at 95 for an hour or so is no problem.  There aren't any places where I have been where I can ride over 100mph for any extended length of time like for a complete tank of fuel.

As I mentioned earlier, they will run at 80-85mph for at least 24 hours.  Can't see where 100mph for that length of time would be a problem.
Title: Re: Is a sustained 7,000 RPM too much? How about 8,ooo?
Post by: beemrdon on February 14, 2017, 03:06:41 AM
Gryph, do you have a 4 valve K of the 3 that you own? I have never ridden an 8 valve (K100/75) so I don't know what kind of power they make.
My K1100 4 valve will cruise at 110 effortlessly, as I have found out. I have upgraded suspension front and rear and also Michelin PR 3 & 4 tires. It feels rock solid at triple digit speeds.
Anyway, once past the prison on 95 N, you can go maybe 20 to 30  miles +/- before it turns into a 2 lane highway. Then you really need to slow down but can stil run at 85 to 90. Cruising at that speed last Sunday, I was passed by an old honda civic going at least another 20mph faster. (That didn't feel right.)
I'm pretty sure that there are other Nevada roads where you can turn it loose but I am still exploring the area and haven't been very many places yet.
As far as using up a tank of gas at triple digit speeds, you'll probably have to slow down occasionally no matter where you are but I think I-80 is a good road for that simply because everyone is driving so fast and it is so long, plus the fact that you can see for miles and miles down the road.
There are probably other roads in places like Texas and Arizona to name a couple where you can "turn it loose"
Title: Re: Is a sustained 7,000 RPM too much? How about 8,ooo?
Post by: The Mighty Gryphon on February 14, 2017, 08:28:43 AM
My K100 is a 4V.  Since it is getting a bit long in the tooth I have been keeping it under 150 miles from home until I feel a bit more confident in it.  It has a lot of power and I have yet to wring it out for fear of the police.  Fastest I've had it is 110 for short bursts. 

My road bike is the K75RT.  Three times now, I've had it out west where I can open up for long runs.  Last summer in central Wyoming I did about 140 miles at a steady 90 with higher bursts.  I could have easily gone faster, but it was evening and there were a lot of antelope coming out along the road. 

To be doing that kind of speed on a 23 year old bike with 80k in the middle of nowhere, solo, 1500 miles from home should tell you what kind of confidence these machines inspire.
Title: Re: Is a sustained 7,000 RPM too much? How about 8,ooo?
Post by: Motorhobo on March 08, 2017, 07:41:26 AM
Well, now that you've all put the fear in me I ran my bike at 80 in third for a half hour just to keep it happy. That's about the only way to get it to 7k rpm around here.

Well, don't do what I did -- since that day second gear has been skipping and now I have big s**t to deal with. Was there a correlation between hi-revs in third and the skipping/slipping in second? I can't prove it but one day it didn't skip and then I rode at 7000k in third and the next day it did. So...don't do it.

I'll start a new thread about this skipping in 2nd thing soon when I have some time. Basically I have one transmission that works fine except for the bad input shaft and one transmission that skips in second but has a good input shaft. I want to put the good input shaft into the good gear transmission and take apart the remaining transmission as a science project...more later.

But bottom line -- my bike has been perfectly happy averaging 5k rpms with an occasional whatever 85-90mph on the freeway gets me -- I don't know why I listened to you redline-fetishists!
Title: Re: Is a sustained 7,000 RPM too much? How about 8,ooo?
Post by: Ultima on March 30, 2017, 11:00:34 AM
When the K1 was launched a journalist had one for a loan by BMW. He picked up the bike at BMW Factory and went down to Sevilla and back at full throttle on the highway. About 2000 km at more than 220 km/h.
Then the motorcycle newspaper gave the bike to every journalist encouraging them to make some bike distance at full throttle, all this for 50.000 km.
Then took the bike back to BMW factory where the engine was dismantled. Result? Barely no sign of use!!!!!!! [size=78%]http://isatis.mecanique.free.fr/K1/50_Mm/p1.html (http://isatis.mecanique.free.fr/K1/50_Mm/p1.html)[/size]
So you can go with your bike.
Read this link in French with google translation. There is a link if you press "site" at one point in the beginning of the text.
By the way, the website of this guy isatis.mecanique .fr is just the Bible for all K fixings and repair...
Title: Re: Is a sustained 7,000 RPM too much? How about 8,ooo?
Post by: beemrdon on March 30, 2017, 01:41:57 PM
I used to have a sooty exhaust pipe end while living & riding around Massachusetts. Now my exhaust end (muffler) is clean. I guess I have been giving the old gal an "Italian tune up" lately.
BTW, It looks like 8,000 rpm in 4th is approaching 120...too much happening all at once to watch the speedometer closely though (pasing a Porche that didn't want to be passed).
Ultima, good to know about the motors..
  :yow
Title: Re: Is a sustained 7,000 RPM too much? How about 8,ooo?
Post by: bizzaro on September 27, 2017, 09:42:37 PM

Beemerdon, you gotta tell us where we can run at 140+mph for more than a couple miles at a time without winding up in the slammer going through Craig's List looking for a new bike, or does your transmission only work in 1st and 2nd gear?
Maybe I should find a different thread........But................Route 9 in Maine between Bangor and Calais.  Almost 100 miles of kick ass highway. Pick a gear, and pin the throttle. I recommend 4..... 5 if you got the balls and more importantly the skills.! Half of it just paved, the rest is in great shape.  Some blind hill tops, corners are perfectly engineered for constant radius, and line of sight is great.  So ya get the angle, hold, and run.................Watch for moose n deer.   Three small towns, traffic nil.............................just did it this weekend.  Fantastic high speed cornering.  :2thumbup: :2thumbup: RPM.............ah, just keep it short of the 89K cut out point. It is all gravy till then!
Title: Re: Is a sustained 7,000 RPM too much? How about 8,ooo?
Post by: mavam on November 22, 2019, 09:40:31 AM
I'm still learning a lot about my new K75 and I specifically searched for RPM because this bike is a bit deceiving (in a good way). It was obvious that it liked to sit higher in the rev range than some other bikes I've had. I wasn't really used to cruising above 4.5k on my previous bike, a Multistrada 1,000 (2v Ducati oil cooled 1000cc), unless I was riding hard in the twisties -- 6-7k would really put smile on my face on that, but not for sustained periods. And below 3k, it did nothing.

The brick seems comfortable anywhere above 3k rpm and goes like a turbine. I'm thrilled to know that shifting at the redline and winding it up to 6k or more at highway speed suits it well. I did just that on my commute this morning. Got to work a bit faster, too  :yawl:
Title: Re: Is a sustained 7,000 RPM too much? How about 8,ooo?
Post by: The Mighty Gryphon on November 22, 2019, 12:28:13 PM
I have heard that the K bike engine is designed to run nonstop at redline for 24 hours. 

I've done continuous 100+mph runs on my K75RT out west for over 50 miles at a time.  I think nothing of doing 85+ for 12-14 hours on the interstate to get through Iowa and Nebraska.  Last year I averaged over 85mph on I-70 crossing Kansas from Denver to Topeka.   These bikes love it.
Title: Re: Is a sustained 7,000 RPM too much? How about 8,ooo?
Post by: Martin on November 22, 2019, 01:47:50 PM
Ayr Highway 1675 Km's of straight road across the Nullarbor Plain. You do however have to share it with Roo's, Emu's, Wombats, Camels and Road trains. A good cooling system is also required.https://www.australiantraveller.com/sa/outback-sa/nullarbor/driving-the-nullarbor-an-unlikely-summer-holiday/
Regards Martin.
Title: Re: Is a sustained 7,000 RPM too much? How about 8,ooo?
Post by: Scott on November 23, 2019, 09:12:26 AM
 [ Invalid Attachment ]
Title: Re: Is a sustained 7,000 RPM too much? How about 8,ooo?
Post by: cycleman on November 28, 2019, 12:28:00 PM
I realize this is an old post, but thought I'd add what is shown in the K100/K100LT owners manual. The K100 manual says max continuous engine speed is 8500 rpm. There is a slight difference between the K75 posted above and the K00. Not sure if the K75 had balance shafts, but if so that is likely the reason for the difference.

The max permissible engine speed on the K100 is 8600 rpm, which would be red line.

Not sure if the brick is like most bikes but it is hard to ever hit 8500 with stock gearing in 5th, as the resistance to wind etc with a fairing is high.
Title: Re: Is a sustained 7,000 RPM too much? How about 8,ooo?
Post by: johnny on November 28, 2019, 12:48:40 PM
greetings...

its easy to hit 8600 rpm in 1st 2nd and 3rd gears... its not how fast you go... it how fast you getts there...

i hitts the rev governour on a regular basis... do you know what happens when you hitts the rev governour...

j o
Title: Re: Is a sustained 7,000 RPM too much? How about 8,ooo?
Post by: Past-my-Prime on November 28, 2019, 07:35:15 PM
greetings...

its easy to hit 8600 rpm in 1st 2nd and 3rd gears... its not how fast you go... it how fast you getts there...

i hitts the rev governour on a regular basis... do you know what happens when you hitts the rev governour...

j o

Johnnie I've never hit the rev governor!  I'm going to have to go now and try it!  Oh, wait air full of cold and driveway full of ice and drive shaft full of not splines. . .
Title: Re: Is a sustained 7,000 RPM too much? How about 8,ooo?
Post by: alabrew on November 29, 2019, 04:05:16 PM
"Not sure if the brick is like most bikes but it is hard to ever hit 8500 with stock gearing in 5th, as the resistance to wind etc with a fairing is high."

That guy on youtube who recorded himself on the autobahn on a k100rs comes purdy close.
Title: Re: Is a sustained 7,000 RPM too much? How about 8,ooo?
Post by: Laitch on November 29, 2019, 04:39:48 PM
https://www.youtube.com/watch?v=cwgWOyVn3fA (https://www.youtube.com/watch?v=cwgWOyVn3fA)
Title: Re: Is a sustained 7,000 RPM too much? How about 8,ooo?
Post by: Past-my-Prime on November 29, 2019, 06:03:08 PM
Wow 250 km/hr.  The road gets very narrow at that speed.

I'm impressed at his restraint, not passing on the right.

I've had my K75 at 220-225 on the Autobahn over 20 years ago (you're not supposed to go that fast if you have a fairing) but it felt rock steady, just faster than my comfort allowed for very long.
Title: Re: Is a sustained 7,000 RPM too much? How about 8,ooo?
Post by: johnny on November 29, 2019, 06:14:21 PM
greetings...

when i rode the audiobahn the rental guy told me not to pass on the right for any reason... the folks i was going to visit told me the same thing...

oughtta be that way here in the usa...

i have had my motometer all the way to 160mph... 2 up of course... needs a smooth dry surface a little or no wind... cause it can getts away from you real fast as it wraps around past the fuel and abs lights on the way back to zero...

j o
Title: Re: Is a sustained 7,000 RPM too much? How about 8,ooo?
Post by: Nine80seven on November 29, 2019, 07:10:11 PM
Illegal to pass on the right on autobahn, IIRC.  240 kph is somewhere around 149 mph.  Speedometer must be rich.  Or, that's not a K100RS.  Maybe a four valve?  Taller rear gear?  Do a hunnerd around here for a few miles, get ticketed, reckless riding.  On two laners county Mounties are watching.  Sad.  Cages are weaving all over the same road playing with their thingees.  I watch that vid whenever I think of it. 
Title: Re: Is a sustained 7,000 RPM too much? How about 8,ooo?
Post by: Laitch on November 29, 2019, 07:29:08 PM
Speedometer must be rich.  Or, that's not a K100RS.  Maybe a four valve?   
Not maybe. In the description under the video at YouTube, the contributor indicates that it's a 1990 4V.
Title: Re: Is a sustained 7,000 RPM too much? How about 8,ooo?
Post by: The Mighty Gryphon on November 29, 2019, 09:47:30 PM
Not maybe. In the description under the video at YouTube, the contributor indicates that it's a 1990 4V.

The bike in the video has a four valve instrument cluster.  See the lines visible on the face of the speedo.  Very possible the actual speed was about 5% lower than shown. 

Still, the ease at accelerating is pretty impressive.   I know from my K100 4V that these bikes have an eagerness to go faster without being alarming which is the result of a wide powerband and lots of torque.

As far as opening up, I have to be careful around here when going 100+.  Law enforcement has been known to seize vehicles.
Title: Re: Is a sustained 7,000 RPM too much? How about 8,ooo?
Post by: billday on November 30, 2019, 07:21:50 AM
I also noticed the ppl moving over for him to overtake. That was my favorite thing about driving in Germany. Felt so much safer than here, even though the speeds were so much higher.

My dad was over there right after WW2. He said you'd get two trucks running side by side for miles in a slo-mo drag race while traffic piled up behind them.
Title: Re: Is a sustained 7,000 RPM too much? How about 8,ooo?
Post by: The Mighty Gryphon on November 30, 2019, 08:09:07 AM
The trucks still do that here with their damn speed governors.  It can take an entire morning for a truck with a governor set at 65.0000001mph to pass another one with the governor set to 65mph.  Of course the asshole driving the slower truck will never back off for 10 seconds to let the "faster" truck pass him.
Title: Re: Is a sustained 7,000 RPM too much? How about 8,ooo?
Post by: Nine80seven on November 30, 2019, 10:02:47 AM
What's the rear gear on that bike?  2.75?  If an old KRS with 2.81 tops out at 137 give or take, that four valve must have one less notch.  30/11? 
Title: Re: Is a sustained 7,000 RPM too much? How about 8,ooo?
Post by: Laitch on November 30, 2019, 10:15:53 AM
If an old KRS with 2.81 tops out at 137 give or take, that four valve must have one less notch.  30/11?
According to the K1/K100RS 4V rider's handbook, the K100RS is 31:11.
Title: Re: Is a sustained 7,000 RPM too much? How about 8,ooo?
Post by: Nine80seven on November 30, 2019, 11:16:16 AM
If it had a 31/11, 2.81, then it'd have to turn a lot more than 8500rpm to get to 150mph. 
Title: Re: Is a sustained 7,000 RPM too much? How about 8,ooo?
Post by: Laitch on November 30, 2019, 12:09:46 PM
If it had a 31/11, 2.81, then it'd have to turn a lot more than 8500rpm to get to 150mph.
I'm just the messenger.

What does a lot mean? What would the difference in mph amount to at 5000rpm?
Title: Re: Is a sustained 7,000 RPM too much? How about 8,ooo?
Post by: Nine80seven on November 30, 2019, 02:49:09 PM
I guess the vid shows a little over 9K rpm which would be about 7-8 hunnerd more rpm, which would be enough for about 12 mph, which would be 150 thereabouts, with a 2.81 rear gear.  All things being equal, tire circumference etc., 2.81 will yield about 16.1 mph per thousand rpm.  Unless I'm losing my mind.  Four valve having ten more ponies. 

It's snowing, sleeting, raining, slop outside.  Fun.  No riding today.  Turkey hash for supper. 
Title: Re: Is a sustained 7,000 RPM too much? How about 8,ooo?
Post by: Laitch on November 30, 2019, 04:57:15 PM
Unless I'm losing my mind.
It could just be the effect of turkey- and potato-generated endorphin affecting perception. :-) That should pass away along with the leftovers.
Title: Re: Is a sustained 7,000 RPM too much? How about 8,ooo?
Post by: cycleman on December 02, 2019, 10:35:38 AM
BMW speedo's are notoriously inaccurate. Not uncommon to have them indicate 6mph/10 km over the indicated speed at 62mph/100kph so hard to say how far out it is at the upper range. Need somebody with a radar gun or timed run to be more accurate.  GPS units are also more accurate than a vehicles speedo.

The video shown, the bike has the newer gauge cluster, so likely not a 2V. With respect to rear ends the 2V had either a 32/11 or 33/11. Not sure if that ever changed through the various brick models.
Title: Re: Is a sustained 7,000 RPM too much? How about 8,ooo?
Post by: Filmcamera on December 02, 2019, 11:04:04 AM
I have had my bike at 200 kph on GPS and the speedo was showing just under 140 mph so yeah the speedo is pretty inaccurate on my bike at least.  I know in theory it is possible to calibrate it but I nearly always have gps open so tend to use that to check my speed anyway.  The bike had more speed in it at 200 kph but I ran out of straight road to keep increasing - not many straight roads here in CR and 95% of the time that is a good thing!
Title: Re: Is a sustained 7,000 RPM too much? How about 8,ooo?
Post by: beemrdon on December 02, 2019, 12:12:44 PM
I had it past the red line once last year while racing a Hardly on 215. It just cut out and died. I'm glad it did or I might have blown the motor.

Also, I had it up to 145 indicated last month. That was just too fast for a 2 lane highway. I was going up a 4% grade and still gaining slowly when I backed off. Full fairing and bags. I think the topcase was on but can't remember exactly.
Title: Re: Is a sustained 7,000 RPM too much? How about 8,ooo?
Post by: daveson on December 02, 2019, 08:31:29 PM
To see if my 30+ year old brick could still do what is claimed when new,  I tried to get it to 200km/h (8,000rpm) It did it easy with throttle to spare,  and that's with three tragkorbs, a taller steeper than usual windscreen and a passenger heavier than me (I'm 90 kg) Sustaining that is something you want to think twice about.

The handling of these bricks gives me more confidence than I probably should have.

It's normal for a speedo reading 100km/h to be clocked at 95 or 96km/h with a speed checker.
Title: Re: Is a sustained 7,000 RPM too much? How about 8,ooo?
Post by: Laitch on December 02, 2019, 08:58:13 PM
It's like being back in high school. I even think my skin tone is improving!  :twothumbsupp
Title: Re: Is a sustained 7,000 RPM too much? How about 8,ooo?
Post by: Nine80seven on December 02, 2019, 09:20:33 PM
IIRC, all K100RS and K1100RS came with 31/11, 2.81.  Standard K100, K100RT, K100LT, and 1100 RT, LT, came with 32/11, 2.91.  Could be wrong but don't want to get up and look because of turkey hash.

Speedos are always off unless you sent it out to get serviced and calibrated.  The guy servicing the unit has to know yer gear.  Not unusual to have different FD with a different gear, like a 2.91 on an RS. 

Airheads are just as bad.  At least ten percent faster than reality.  Always thought I was going around eighty.  After calibration with  33/11, at 4K, more like 68.  R90S.  FWIW.
Title: Re: Is a sustained 7,000 RPM too much? How about 8,ooo?
Post by: billday on December 02, 2019, 09:47:00 PM
K bike  speedos are consistently 10% fast. I  checked that out while running a bicycle speedo which was spot-on (I checked it against those speed warning signs that flash your mph).

A free program called Karamba  works to calibrate your bread box.
Title: Re: Is a sustained 7,000 RPM too much? How about 8,ooo?
Post by: The Mighty Gryphon on December 02, 2019, 09:53:38 PM
I used Karamba to calibrate three of my speedometers.  What I found with mine was that I had to turn the adjustment pot all the way to the stop to get close to an accurate reading.  Even then, my K75RT speedo still reads a mile or two higher than my GPS when hauling a** across the Great Plains.
Title: Re: Is a sustained 7,000 RPM too much? How about 8,ooo?
Post by: Laitch on December 02, 2019, 10:22:07 PM
IIRC, all K100RS and K1100RS came with 31/11, 2.81.  Standard K100, K100RT, K100LT, and 1100 RT, LT, came with 32/11, 2.91.  Could be wrong but don't want to get up and look because of turkey hash.
Your RC seems to be RI. I can't find a K1100RT but the published RS specs differ from your recollection. Also, there were variations among the ordinary 2V. Continue with your flatulence. I'll fill the gap until you resume consciousness. :-)