Topic: 76 CB 550 top speed question?

[Brandotheamazing]

Hey, just wondering what a 76 cb550f SS should top out at? i've been doing some highway riding, and it cruises easy at 70, and has more, just about 100... just wondering if it should have more? i know it's been beaten and neglected, tortured, crashed, and forgotten before i bought it, but i got it running pretty strong (much stronger than the 76 500 twin i had a few years back) just don't know what it should be capable of.
-B

[the technological J]

yeha around there isnt too bad if you have it tuned really great u might be able to get another couple (stock sprockets and wheels) minw barley hit 75 when i got it... i rebuilt the carbs and she hit around 105... give or take i dunno how close the speedo was... for real acuracy use ur gps

[Ichiban 4]

I've had my '77 550 K up to about 90 mph.  Don't know that I'd want to push it much over that..not because it wouldn't do it..but because the bike's so old (only 10k miles on speedo though).  I start suspecting that something could go wrong.  It doesn't track like a newer bike (old wheels..bearings..etc.)..either.

HOWEVER..I did ride both a new '73 450 twin..and '74 500-four..both of which could easily and safely go over 100  mph..at that time.  I've heard quite often..that when everything is right with the 550's that they could/can go to about 110 mph.  Think Lloyd/twotired..if he reads this..would know more about that.

Bottom line seems to be that if the 550's are in very good/knowable mechanical condition (as with a complete restoration)..they should be able to cruise along @ 100 mph..no problem.

Ichi

[TwoTired]

Here's a copy of an old magazine report.

[SteveD CB500F]

Call it 100.

Add speedo inaccuracy and you should see 110 on the clock.

Sounds about right.

[73hutch]

i hit 100mph on my 550f just to see if it would go there. it didn't really feel safe though. mine feels best at 70-75mph!

[traveler]

100 MPH sounds about the best that can be expected, personally.

Keep in mind, your brakes, stock tires, etc. are not good for this, and it is a dangerous practice, unless you have modern tires, etc.

100 MPH on this bike will feel like 150 MPH on a modern sportbike!
 
~Joe

[Pirate Gonzo]

My 76 550k Tops out around 125 (per speedometer) with me on it and 130-135 with my girlfriend on it. Not sure how accurate speedo is but I do know that the PO of the bike had a lot of work done to the engine I just don't know what. My girlfriend weighs 60 pounds less than me so I am sure that has a lot to do with it.

[the technological J]

sounds like alot of work! ur bike is certainly the exception to the rule

[ieism]

My first 550F SS had a stock motor, and did 177 km/h (110 MPH) on the speedo. I think the gearing was not stock though. There's no need to be scared of riding at these speeds, if you're bike is in good condition it will do this all day long. I did a 500 mile trip in Germany pretty much all of it over 100 mph, the bike seemed to run better than ever when I returned home.

Just be very carefull and keep lots of distance, braking takes forever at these speeds. And wear you best helmet and suit.

[Brandotheamazing]

Nice to hear tha bike is actually doing well! I won't be hitting 100 often, as the bike is old, and motor is original, and I need the thing to stick together for gettin to and from work till i get a new car. then i'll build a motor for the bike.

It cruises most comfortably at 70 with or without a passenger.

[Bluto]

Bought my 76 550K new when I was 17.  Back then 100+ was no problem.  I stored her well for about 29 years, got her out a few years ago and...I have no doubt she can still pull 100+.

The strange part is......I can't get my right wrist to bend that far anymore.  

Back then all I thought about was......man this is cool!!!!!

Now all I can think about is.......:

The wheel bearings could lock
The chain could break
A tire could let go
A rock or pothole could take me out
A ticket at this speed would cost $$$$$$$$$
If I lived through a crash...my wife would kill me

The bike will still do it

The guy with the throttle in his hand is no longer "Bullet Proof"

You youngsters be careful and...trust me...If you make it to 50 yrs (or so) your right wrist WILL NOT twist as far it used to.

[Accolay]

New paint adds at least 10mph.

[crazypj]

Just about every bike I've ever owned would do same top speed as road tested.
 Major reason bikes in good condition, properly serviced are slower (in my experience) is 'limp wrist' problem.
 If you can't turn throttle far enough to get it wide open,  (bad idea anyway, I've had carpal tunnel decompression) grab throttle further forward initially
 Many, many years ago 'we' sold a Kawasaki GPZ 900 to customer who expected to drop it in top gear at 30~40mph and reach max speed on local roads 
 I took him for a test ride and hit an easy (indicated) 145mph by redlining through the gears. ( I was younger and crazier then  )
 Never came back complaining again 

[Bluto]

gears. ( I was younger and crazier then  )
 Never came back complaining again  

Younger and crazier + 30 years = Older and wiser = Bike don't go as fast as it used to.

[Laminar]

My girlfriend weighs 60 pounds less than me so I am sure that has a lot to do with it.

Top speed is a function of horsepower, rolling resistance of the tires/bearings, and wind resistance. Weight has very little to do with it.

[crazypj]

Forgot to mention, 550 in my avatar is doing ~100mph in 4th gear, not too bad for 100,000 miles  

[Gordon]

My girlfriend weighs 60 pounds less than me so I am sure that has a lot to do with it.

Top speed is a function of horsepower, rolling resistance of the tires/bearings, and wind resistance. Weight has very little to do with it.

You're correct in that weight doesn't really factor into top speed, but if she's 60 pounds lighter I'm sure she's quite a bit smaller in size, too, and wind resistance makes a very big difference. 

[Laminar]

My girlfriend weighs 60 pounds less than me so I am sure that has a lot to do with it.

Top speed is a function of horsepower, rolling resistance of the tires/bearings, and wind resistance. Weight has very little to do with it.

You're correct in that weight doesn't really factor into top speed, but if she's 60 pounds lighter I'm sure she's quite a bit smaller in size, too, and wind resistance makes a very big difference. 

As I mentioned.

[Gordon]

My girlfriend weighs 60 pounds less than me so I am sure that has a lot to do with it.

Top speed is a function of horsepower, rolling resistance of the tires/bearings, and wind resistance. Weight has very little to do with it.

You're correct in that weight doesn't really factor into top speed, but if she's 60 pounds lighter I'm sure she's quite a bit smaller in size, too, and wind resistance makes a very big difference. 

As I mentioned.

Yes you did.  Must have skimmed over that.

[THE DUDE]

Ok tried to Ton up on mine today with the TOM TOM mounted on the Gauges my speedo was about 5-10mph off at times.  I hit 98 on the GPS and 105 on the speedo.  I have a 74 cb550 and the front end does not feel secure at those speeds so I didnt keep it up for long plus I was trying to think of a good excuse for the Police if I happened to be stopped.   

[Pirate Gonzo]

I had my Garmin on the bike today. The speedo is pretty much spot on up to 35-40 mph. Beyond that it seems to lose mph (or gain, however you want to say it), 60 speedo mph I was doing 55 gps mph. At 80 speedo mph I was doing about 73 gps mph. I am guessing it keeps going down from their but I'm not sure and I was in no position to go any faster than I was.

Just wondering is their a way to adjust that out and what causes it to start falling off as I go faster?

And Crazypj... how did you take the picture at that speed going around a curve?? I always wanted a pic like that.

[Gaither]

Pirate - IMO, if you like your GF you wouldn't haul her around anywhere near that fast. You just might get her killed and you wont feel right about it. It's optional to injure or kill one's self but take good care of that GF - she's someone's daughter. [No offense - Just the thoughts of an old man.]

I've driven cars up to130 many times, in days gone by. Had the 550 to 70 but mostly run 55 to 65. On public roads I've always fugured above 70 you're "mostly riding" and not really in complete control of events [although I run 75 to 85 on interstates where it seems OK]. Above 70, things that go wrong happen pretty quickly!

Still have a Crown Vic Interceptor and an HPP. 'Don't know how fast either will go - and wont be finding out. I do enjoy the good "bottom end" frequently. Reflexes are still good.

When I quit riding at 23 [got back on last summer] it was because I could ride a block and didn't have a care in the world nor a lick of sense. Finally realized I couldn't continue to ride crazy and live. We called it "young and insane". All that is gone out of me now and I just CAREFULLY enjoy the ride.

As I said, just the thoughts of an old man.

On speedo's, I hear that Honda was always a little ambitious on the high side of the mph.

[Laminar]

Pirate - IMO, if you like your GF you wouldn't haul her around anywhere near that fast. You just might get her killed and you wont feel right about it. It's optional to injure or kill one's self but take good care of that GF - she's someone's daughter. [No offense - Just the thoughts of an old man.]

Do you believe he's saying that the bike goes faster with two people on it?

[Gaither]

That ain't exactly what I said.

Example: We had a guy here - crotch rocket - with his GF on the back. He did a wheely at a too fast speed. She slid off the back and was in really BAD shape. Can you imagine how stupid he feels?

[I'm confident you know what I said and what I meant.]

[crazypj]

My 76 550k Tops out around 125 (per speedometer) with me on it and 130-135 with my girlfriend on it. Not sure how accurate speedo is but I do know that the PO of the bike had a lot of work done to the engine I just don't know what. My

 I have a 591 kit, ported, cam, exhaust and all the carb mods that go with it
Oversize tyres slowed speedo down a bit but it still went 'off the clock' (but really never went over 127mph)
 Its much cheaper to make a 'RTS' (race tuned speedometer'  )
 I think you have a 'special' speedometer as mine stops at 120 (see pic on left)

And Crazypj... how did you take the picture at that speed going around a curve?? I always wanted a pic like that.

 Easily  
 I just had camera around my neck on strap and pushed button. (only need one hand to hold throttle  )
 Cosina CSR, 50 or 80mm lens, pre-focus, forget film and exposure (probably Fuji film and 1/250th sec)
I used to be 'into' photography a bit  

PJ

[Pirate Gonzo]

Easily  
 I just had camera around my neck on strap and pushed button. (only need one hand to hold throttle  )
 Cosina CSR, 50 or 80mm lens, pre-focus, forget film and exposure (probably Fuji film and 1/250th sec)
I used to be 'into' photography a bit  

PJ

Yeah, now I know why they call you crazypj.

 

Pirate - IMO, if you like your GF you wouldn't haul her around anywhere near that fast. You just might get her killed and you wont feel right about it. It's optional to injure or kill one's self but take good care of that GF - she's someone's daughter. [No offense - Just the thoughts of an old man.]

No, I didn't have her on the back of the bike while doing this. She was on the bike by herself and we were on a closed track at a rally and they wouldn't let you on the track with out proper gear. Full face helmet, jacket, pants, boots, and gloves.

 I think you have a 'special' speedometer as mine stops at 120 (see pic on left)

Mine also tops out at 120 but has markings for 125 and 130. It just doesn't "say" 130. I can't really see your pic that closely, does yours not have the extra markings? I'm pretty sure the speedometer is stock up to 130 markings for the 550.

[Laminar]

That ain't exactly what I said.

Example: We had a guy here - crotch rocket - with his GF on the back. He did a wheely at a too fast speed. She slid off the back and was in really BAD shape. Can you imagine how stupid he feels?

[I'm confident you know what I said and what I meant.]

I know what you said and what you meant, and I know that you interpreted his post incorrectly.

It was pretty clear to me that she was on the bike by herself going that fast.

[Gaither]

OK - Now I see your point.

I assumed [incorrectly] they were riding double. After reading it again, I apologize to all involved. [This likely wont be my only mistake.]

Thanks for calling my attention to my error in reading the post.

[Pirate Gonzo]

No problem. I just don't want people thinking that we're ripping up the roads. We take safe riding very serious. We both have taken rider's safety and believe in the 5=Zero in Wisconsin campaign.

[MCRider]

The comments using the GPS were on the mark. That's the only way to really know, or timing traps like at the drag strip. Top speed conversations comparing 30+ year old speedos, regardless of their mileage (time and gravity still does their damage) are wasted breath. But fun bar talk.

Also, attention to the road tests tells the tale, per TT. Those guys are at sea level, are using timing traps, and usually know how to get the last bit out of a bike. Doubtful any of us can do better.