Topic: How high do you get on the tach?

[andy750]

Reading Rachets excellent ride report of his evening ride:

http://forums.sohc4.net/index.php?topic=59135.0

made me realise I am probably not using the full potential of my engine. Dont get me wrong I do ride fast but I likely baby my engine never going beyond 7K on the tach and thats only once in a while.

So question is - what is the usual tach rpm range you operate in and in what gear? (this applies to CB750s but if have another bike please specify).

I am guessing that running at higher rpms will shorten the life of the engine? Thoughts on this as well are welcome....

thanks
Andy
 

[BVCB650]

5500 rpm but I'm old and less stones than I used to have. On my 650 of course.

[Laminar]

The SOHC does't seem to have the massive upper RPM leap in power like the newer DOHC 4 cylinder bikes so I rarely bother going over 8 or 9k. Most of the time when I'm tearing around I shift by 6 or 7k.

[fasturd]

Well I am 45+ and any motorcycle I have gets all of its rev range used on almost every ride. The only exception is my ZX12 because red line in any gear on that thing is a ticcket and or jail time.
And maybe its the pipes or the state of tune but my 750s pull hard all the way up to and PAST red line if I am not carefull. But everyone has their zone. My S/O has a nice little 400F that would never see above 4K on the tach if I didn't take it out once and a while to keep her loose...

[BobbyR]

I like Andy tend to baby the motor a bit. I kave a 78 750K. Around town I try to keep it in the 4K range since that is where the power band kicks in and if I need to pass someone quickly or avoid something, she hops well. I also I use a lot of engine braking.

Getting on the highway I will kick it up to 7K in 3rd to merge into traffic and not get run over. I can then just shift directly into 5th. I run the highway at 70 mph so my tach shows around 5K +/- . 

Mine likes to run at 5K rpm, after an hour, she idles much better. I am not sure why exactly, but it does. 

[sparty]

I ride in the 6K to 7K range because of my 125-75 cam.  Andy, it really took me a long time to accept that riding in this range wouldn't hurt the engine, because I was use to my modern sport bikes or the twins I owned.  My bike sees 9K in 2nd and 3rd daily.

Art

[rachet]

Thank you Andy for starting the thread I was going to!

When I first started riding, I would shift way to early.  It wasn't a problem, and I thought I was doing it right.  It "sounded" right.  When I had a mechanic look it over, he was telling me about doing 80 in third gear and I about freaked!  However, he explained that the power range for my bike (again, a 750f2) really didn't kick in until the higher RPM's.  I started experimenting and dang it if he wasn't right.  The motor is just tooling along in the 5K range, and accelerates hard as I increase the Revs.  It really is around 9-1/2K when i stop accelerating, but then I shift... and BAM!  The Tach usually drops to 4 or 5k, and I start accelerating again.

What I would like to know is, Why does it run better at higher Revs, unlike other bikes I've ridden?  The Cam perhaps?

Rach-

[Gordon]

Depends on what type of riding I'm currently doing.  If I'm in town or just going to work I usually keep the 750 below 5K.  Not for any particular reason, but there's just not much use for a higher rpm when I'm not going over 40mph.  On the interstate or out for a ride in the mountains it's almost always above 5K and up to redline because that's where the power and fun is. 

I agree with people who say that classic motorcycles should be ridden instead of just looked at because that's what they were made to do.  I also think that they should be ridden the way that they were made to be ridden, and where sohc4's are concerned that's in the upper RPM range.  There's a whole lotta tach left between the 5K mark and Redline.  I say use it!

[754]

I used to run my 836 with a cam to 11K or 11,500, if I remember right. Probably hit at least 10 K daily, most of the time.. Then, for a long time I ran without a tach and shifted by feel.

 Right now I am riding my buddies stocker with 4 pipes.. dont know if its the p pipes vs headers, but I never took it over 7K yet.. it just doesnt feel like its pulling that hard,  maybe because it is after having ridden a cammed motor.

 Before I had a hotrodded one, I usually shifted at 8k or a bit higher, and ran up to 9k  a few times.. stock motor, header, pods, coils..

[mlinder]

8 to 11.5k......

[Frankenkit]

I baby my engine a little, and like to keep it quiet(er) around town, so 4-5k in 'town' real close to people and I'll open 'er up to 6-7 on bigger, longer stretches and usually shift around 7.5k or 8.  70 or so in third has happened um... heh.... a few times...

[kvallelunga]

I run it to 9000+ several times on each ride. She likes to be ridden that way. I figure if the engineers ok'd a 9500 redline, that's where they wanted it to run.

[Johnny5]

Have no idea, honestly. My tach needle will sometimes get buried, but I wonder how accurate it is. I swear the bike begs for more...

[tlbranth]

I shift at 4k. So most of the time I'm running 3K - 4K. Sorry, I'd like it to last.

[Johnny5]

I shift at 4k. So most of the time I'm running 3K - 4K. Sorry, I'd like it to last.

You're on a Honda 750, not a Mazda Miata.     

[Gordon]

I shift at 4k. So most of the time I'm running 3K - 4K. Sorry, I'd like it to last.

No reason to apologize.  It's your bike, ride it how you want to, but using the engine the way it was designed to be used isn't going to hurt it.  

Oh, and 3-4K on a 750 is lugging it, and lugging an engine can hurt it. 

[BVCB650]

I usually run around town at 4K. Seems like a medium rpm for 25 mph speeds and stop signs and all. My 650 doesn't sound like it is struggling.

[BobbyR]

I shift at 4k. So most of the time I'm running 3K - 4K. Sorry, I'd like it to last.

No reason to apologize.  It's your bike, ride it how you want to, but using the engine the way it was designed to be used isn't going to hurt it.  

Oh, and 3-4K on a 750 is lugging it, and lugging an engine can hurt it. 

I read what other people do and that is fine with me. I like a combination, I have probably gone 9K on one of my miss shifts. I know i have done 8K a few times this year.

I am not sure it is good for the overall health of the motor to either run it slowly or run it balls out all of the time. Probably a combination of the two is best.

One thing to consider is that most of us are not the original owner. While new and well maintained these motors could go balls out.

If you are the 3rd owner or more, how would you know the if the bike had good maintenance over the last 30 years. Looking at the threads you see some real horrors. So, i run around town shifting at 4K and keep it there. When my need for speed breaks out, I have no qulams about 7K shifts.

[myhondas]

1ST to 2ND I shift at about 6500-8500
2ND to 3RD I shift at about the same rpm
3RD to 4TH     ditto the above
then settle in at about 4-6K in fifth


But that is only when I want to ride like the wind......like most of the time...

PS:  took it to 9K in fourth to 107mph on the 750K4

[andy750]

All great replies - thanks everyone!

Myhondas - good detailed reply!

I need to go practice now  .

Keep in mind I have been riding for 19 yrs  - 18 of those on CB750s. Ive had the bike to flat out speeds on the Autobahn with the tach around 7-8K, WOT for a couple of hours or so. But usually shift it in the 6-7k range. Now Ill try something new  . Never too old to try something different. I know my bike inside out having rebuilt it a couple of times now. It has less than 8,000 miles on the rebuilt top end. But good point Bobby!

cheers
Andy

[BVCB650]

I shift at 4k. So most of the time I'm running 3K - 4K. Sorry, I'd like it to last.

No reason to apologize.  It's your bike, ride it how you want to, but using the engine the way it was designed to be used isn't going to hurt it.  

Oh, and 3-4K on a 750 is lugging it, and lugging an engine can hurt it. 

I read what other people do and that is fine with me. I like a combination, I have probably gone 9K on one of my miss shifts. I know i have done 8K a few times this year.

I am not sure it is good for the overall health of the motor to either run it slowly or run it balls out all of the time. Probably a combination of the two is best.

One thing to consider is that most of us are not the original owner. While new and well maintained these motors could go balls out.

If you are the 3rd owner or more, how would you know the if the bike had good maintenance over the last 30 years. Looking at the threads you see some real horrors. So, i run around town shifting at 4K and keep it there. When my need for speed breaks out, I have no qulams about 7K shifts.

You could an overall check up on your bike to determine it's "health"
 by doing compresion checks etc. Barring metal fatige, It probably doesn't have any feelings that might get hurt.

[paulages]

on quick acceleration, i often hit the rev limiter (10,500) on the 718, but once up to speed it usually stays in the sweet spot, which the dyno tells me is 8-10K. i don't have a tach currently, but i'd like a digital unit at some point. i can definitely feel the engine lug and even ping if i don't keep it spun up where it wants to be.

[TwoTired]

Anything below the Red mark on the tach is fair game.  The tach is like a fun meter; the higher it goes, the more fun.

Anyway, the 550 doesn't have the low end torque of bigger displacement engines.  So, to make it scoot you need at least 4000 RPM to get much in the way of throttle twist reaction.  So, in traffic, I'm never below that RPM except when approaching a stop.  If you want to really scoot, drop down two gears.  But, shifting can take away precious avoidance time, which is why I keep the R's up to have some throttle twist action.
This is also related to why I like a quiet exhaust system.  Screaming engines are noisy, which the rider notices less than those near by, particularly infirmed shut ins who usually have enough misery to deal with.

I don't really have that much 750 seat time.  But, I expect the same "anything below the Red line" should still apply.

[rachet]

I've been waiting for your insight Paul!  while those annoying little things like "life" and Financial "obligations" have postponed my 550/650 big bore motor, I will build it.  And I like running at the Higher RPMs, so I'm glad that's where your bike sits.

Woot!

Rach-

[BobbyR]

I shift at 4k. So most of the time I'm running 3K - 4K. Sorry, I'd like it to last.

No reason to apologize.  It's your bike, ride it how you want to, but using the engine the way it was designed to be used isn't going to hurt it.  

Oh, and 3-4K on a 750 is lugging it, and lugging an engine can hurt it. 

I read what other people do and that is fine with me. I like a combination, I have probably gone 9K on one of my miss shifts. I know i have done 8K a few times this year.

I am not sure it is good for the overall health of the motor to either run it slowly or run it balls out all of the time. Probably a combination of the two is best.

One thing to consider is that most of us are not the original owner. While new and well maintained these motors could go balls out.

If you are the 3rd owner or more, how would you know the if the bike had good maintenance over the last 30 years. Looking at the threads you see some real horrors. So, i run around town shifting at 4K and keep it there. When my need for speed breaks out, I have no qulams about 7K shifts.

You could an overall check up on your bike to determine it's "health"
 by doing compresion checks etc. Barring metal fatige, It probably doesn't have any feelings that might get hurt.

I grant you that you can get some idea of your engines health from the checks you do. There is a whole lot of high stress parts down below that can get fatigued and worn. Running a bike low on oil is gonna get the bearings first.
I am an all things in moderation kinda guy at this point in my life.