Topic: anybody have firsthand 1/4 mile specs on these bikes??

[dr. destructo]

Just wondering how fast/slow these bikes are (or could be) , whether stock or modified.  Just looking for some head knowledge,, I know their not the fastest bikes in the world but just curious.   any and all combos/ models welcomed. 
thanks

[scondon]

   Check the "I saw it really..." post in the open forum. There is a link to an article that lists 1/4 mile times for different engine set-ups (p.2-3, I think). 10.39(race engine,pro rider) to 15(Joe Schmo, stocker).

[ProTeal55]

When talking about drag racing motorcycles, I would say the rider is 60%, and the bike is the other 40..
I have seen one guy take a stock GSXR 750 and run a bottom 10 sec pass, where on the same bike, some novice cant break into the
11's.

I would be curious to see what these bikes actually run, but to guess, I would say somewhere in the high 14's for a stock 750...

[Sam Green Racing]

Sorry teal man, CB750 13.4, stock. With a top notch rider, same bike 12.9. (first hand)....well it would be if Chris would let me play on it long enough 

Sam.

P.S. Nice truck by the way.

[HondaMan]

Here's the numbers I have for stock 750s:
CB750K0 : 12.60/102 MPH (1969, in Peoria, IL).
CB750K1 (my own) : 13.21/99 MPH (1970, Peoria)
CB750K2 (several) : 13.45, 13.66, 13.70, 96-98 MPH (Peoria)
CB750K2 with 17-tooth countersprocket: 12.99/101 MPH (Peoria)
CB750K2 with 18-tooth countersprocket (stock again) : 13.66/91 MPH (Denver, CO, 6800 ft altitude). NHRA says drop .5 sec for 6800'.
CB750K4 : 13.55/96 MPH best in Macomb, IL. (1974)

The gearing changed a lot on the CB750: K0 was 16T/45T sprockets, K1 was 17T/48T, K2 and later "K" were all 18T/48T sprockets stock. The tranny never changed, not did the primary drive ratio or tire sizes. The changes were due to wear problems with the drive chains.

[putnaja1]

Here's the numbers I have for stock 750s:
CB750K0 : 12.60/102 MPH (1969, in Peoria, IL).
CB750K1 (my own) : 13.21/99 MPH (1970, Peoria)
CB750K2 (several) : 13.45, 13.66, 13.70, 96-98 MPH (Peoria)
CB750K2 with 17-tooth countersprocket: 12.99/101 MPH (Peoria)
CB750K2 with 18-tooth countersprocket (stock again) : 13.66/91 MPH (Denver, CO, 6800 ft altitude). NHRA says drop .5 sec for 6800'.
CB750K4 : 13.55/96 MPH best in Macomb, IL. (1974)

Whew!  Right-On!!!  12's!  Man, that would sure put a smile on my face to see someone run one of these old war horses to a 12 second quarter mile!

Any first hand ideas on what a 550 will run one in? 

[scunny]

the only certificate I could find for my 1972 500 (amongst the speeding tickets) was 14.47 seconds, I think that going by the date it would have been stock apart from a 4into1

[chung]

Low 5s in the 1/8. @ sea level. Pro bike, Pro rider. (7 inch slick?)

[toycollector10]

Thanks for that HondaMan...was the K0 fastest because it had a different profile on the cam and a different baffle setup in the unstamped pipes?

Why was it faster?, in other words.....

[BMan1113VR]

Here's the numbers I have for stock 750s:
CB750K0 : 12.60/102 MPH (1969, in Peoria, IL).
CB750K1 (my own) : 13.21/99 MPH (1970, Peoria)
CB750K2 (several) : 13.45, 13.66, 13.70, 96-98 MPH (Peoria)
CB750K2 with 17-tooth countersprocket: 12.99/101 MPH (Peoria)
CB750K2 with 18-tooth countersprocket (stock again) : 13.66/91 MPH (Denver, CO, 6800 ft altitude). NHRA says drop .5 sec for 6800'.
CB750K4 : 13.55/96 MPH best in Macomb, IL. (1974)

Whew!  Right-On!!!  12's!  Man, that would sure put a smile on my face to see someone run one of these old war horses to a 12 second quarter mile!

Any first hand ideas on what a 550 will run one in? 

high 13's with a pro rider. . . more realistically mid to low 14's

http://www.dragtimes.com/Honda--CB-Drag-Racing.html

[HondaMan]

Thanks for that HondaMan...was the K0 fastest because it had a different profile on the cam and a different baffle setup in the unstamped pipes?

Why was it faster?, in other words.....

The K0 had several advantages in the 1/4. One was lower gearing (16T front, 45T rear), glass-packed mufflers that were straight-thru design, tuned for performance, faster spring advance in the spark advancer, and, in the first 3 or 4 month's production, a cam with a little more lift and duration. You can tell right away which bikes the "hot" ones were by looking at the tach: the redline was 9200 RPM until the 3rd month of production, when it dropped to 8500 RPM. By the K1 model (10th month of production) the tach had an 8000 RPM redline. The cam change accompanied the 8500 RPM change: it's been the same cam since then, until the "F" series came along. All the pipes were "stamped", but the earlier ones had a little handwork on them to clean them up. This disappeared with the "sandcast" engine cases, mid-K0 production or so.

Honda suffered high warranty claims, because they had not anticipated how much Americans would abuse this bike. (I can tell you some horrific, almost unbelievable, first-hand stories I saw...)The result was the long, silent detuning history, down to the K4 model. Honda was more concerned about reliability than performance while Sochiro was in charge.

[Bob Wessner]

(I can tell you some horrific, almost unbelievable, first-hand stories I saw...)

If you mean about how bikes were treated, I would be interested in hearing a couple. If it includes what happened to the owners/riders as a result, I guess I can pass. 

[scunny]

this is when Kawasaki came into the picture.. fast bike, no brakes and a hinge in the frame...IMO

[puppytrax]

Just wondering how fast/slow these bikes are (or could be) , whether stock or modified.

I posted a couple of Cycle World CB500/550 test results from back "in the day"  in another thread...have a look...

http://www.wzrd.com/~rbrennan/misc/cb500.jpg

http://www.wzrd.com/~rbrennan/misc/cb550.jpg

[GroovieGhoulie]

Thanks for that HondaMan...was the K0 fastest because it had a different profile on the cam and a different baffle setup in the unstamped pipes?

Why was it faster?, in other words.....

The K0 had several advantages in the 1/4. One was lower gearing (16T front, 45T rear), glass-packed mufflers that were straight-thru design, tuned for performance, faster spring advance in the spark advancer, and, in the first 3 or 4 month's production, a cam with a little more lift and duration. You can tell right away which bikes the "hot" ones were by looking at the tach: the redline was 9200 RPM until the 3rd month of production, when it dropped to 8500 RPM. By the K1 model (10th month of production) the tach had an 8000 RPM redline. The cam change accompanied the 8500 RPM change: it's been the same cam since then, until the "F" series came along. All the pipes were "stamped", but the earlier ones had a little handwork on them to clean them up. This disappeared with the "sandcast" engine cases, mid-K0 production or so.

Honda suffered high warranty claims, because they had not anticipated how much Americans would abuse this bike. (I can tell you some horrific, almost unbelievable, first-hand stories I saw...)The result was the long, silent detuning history, down to the K4 model. Honda was more concerned about reliability than performance while Sochiro was in charge.

Does anyone have a pic of the supe-early tach?  i've always seen the ones with the redline that starts at 8500 and ends at 9200.  Never seen one that started at 9200.

[eldar]

Too bad no one has the times for the k8. It had a 15/45 sprocket setup. While I am certainly no expert, it certainly seems to accelerate well. I still need to do a sync yet and finish tuning my mix screws though. I must say however that I get very little clutch noise at idle.

[chung]

I don't have the parts or specs handy but the 77-78 bikes had different a primary drive ratio. In doing a #530 chain swap I discovered that somewhere in the neighborhood of a 16/48 restored it back to near the original ratio of the #650's 15/45.

With the first set I used a 18/48 set and it was way too much gear aomething like 90mph @ 4krpm. A 17 tooth front helped but still too tall.

[joeson]

my original 78k in 1986 was undressed by a Kawasak Intruder" 900cc ninga"
top speed for me 180 klms , kawi blew by at twice that ... corners and stopped better too ....?
best to massage the old girl than drag her but for sure ride it hard