Topic: The 1970 Daytona CR750s.

[Sam Green Racing]

Thanks for that but sadley, Woody is no longer with us, he died back in 91.

Sam.

[coyotecowboy]

..and the fantastic 6 cylinder 250.

Always wanted to see one of these engines with the head off, wonder if he has such a picture? In any event, look forward to his and other's presence here.

Hey Bob, I think I have some pics of one of the RC 166's engines torn mostly apart, can't remember where I stumbled onto them though   Give me a holler if you want them, I'm not bright enough to post pics

[Bob Wessner]

Supplied by, and posted on behalf of Coyotecowboy. The rod/piston assembly almost looks as though it came from a realistic model.

[bwaller]

You're right Bob, pretty tiny. Imagine the 125-five cylinder. I supppose it's one of the directions Honda followed to able to compete with the two strokes, just by adding more little pistons, intricate stuff indeed!

Thanks for this Coyotecowboy, do you know what the other two engines are?

[coyotecowboy]

I think one of the engines is from an RC 172 GP Honda

The RC 166 250cc redlined at about 17,000 rpm.  But the little RC 149 125 5 cylinder could hit an insane 20,000 rpm!!!  In 1966!!!

[bwaller]

I witnessed a 250/6 at Mosport and can only describe its exhaust note as like "organ music" with those six open megas. It could be heard the entire way around the track and this was for a few parade laps not full nuts racing!

 I grew up diggin race track action, didn't protect my hearing, and that's what I blame for my bad tinnitus (damn expansion chamber stingers). I wonder how the guys that rode or worked on these small four stroke machines fare in that department? They are LOUD too.

[okie]

What?  Speak up, boy.  I can't hear what you are saying.

[Bob Wessner]

This loud enough?

http://www.zippyvideos.com/4136186674481836/rc166/400k

[bwaller]

Pretty cool Bob, took about an hour on dial-up though!

[malcolmgb]

 I grew up diggin race track action, didn't protect my hearing, and that's what I blame for my bad tinnitus (damn expansion chamber stingers). I wonder how the guys that rode or worked on these small four stroke machines fare in that department? They are LOUD too.

my problem too, I spent most weekends through the 70's helping a friend who raced first a Yamaha 125 then 250's, a collecting area of about 30 screaming unsilenced 2 strokes was not healthy, aaah the innocence of youth. 

[HondaMan]

Wonderful pics!
I always wondered just how small the sixes were inside. I worked on some of the 250/4 engines, they were tiny (and also reached 18,500 RPM). But that one is really cool!

[Jinxracing]

This one's cool too...

[Sam Green Racing]

I think one of the engines is from an RC 172 GP Honda

The RC 166 250cc redlined at about 17,000 rpm.  But the little RC 149 125 5 cylinder could hit an insane 20,000 rpm!!!  In 1966!!!

Here's ya 125/5 cowboy, enjoy.

Sam.

[bwaller]

Unreal stuff guys. Nice to see this exotica is not placed on a shelf somewhere.

[ekim98]

I watched about 4 or 5 of those video's, man those bikes really get some rpm's going. Even on a smaller bike like that it's got to be quite a rush. I wonder how much they buzzed thru the grips, pegs and seat?

[coyotecowboy]

Thanks Sam!!!   Thats pretty cool stuff

[736cc]

http://www.m3racing.com/pressmedia/CWjune2000/cycleworld.html

[Mark M]

Interesting thread - not logged on for a loooong time so this took me by surprise.

Sam - One of the questions I have been trying to answer is - the top fairing on Manns bike has
a white stripe running under the screen in some pictures but not in others (pictures described as being taken during the race) Anyone know which he used during the actual race - or was it swaped over at some point?

What I haven't seen mentioned is the bike that turned up in a dealers in Paris which has since been
accredited by Hansen as being 'The Bike' - that has different fork bottoms, but I don't remember them being part of the race kit.

I've heard stories on various titanium parts being used on engine internals - except on Manns bike (which most certainly was the least powerful) this surely has a lot to do with why his engine held out to the end. Along with Manns Daytona experience and understanding of the need to follow the .....to finnish first...first you have to finnish....principle.

Neither Hansen or Mann had a continued relationship with Honda......I don't think we will ever know the full story on that.......I'm sure there is a 'cultural' element to it.

       

[Sam Green Racing]

Hi Mark, nice to see you again.  There are quite a few pictures about showing the number 2 bike with 3 different fairings.
there is one showing the white line along the top and a black circle round the side number 2.  Another shows the black circle but not the white line. The fairing he used in the race had neither the white line or the black circle as can be seen in the picture where he is leading the pack from the start of the race.

Regarding the forks Mark, there were special forks offered in the race kit. They can be seen in the picture of the race kit on the front cover of Cycle magazine elsewhere in this thread.

Regarding why he finished and the others didn't wasn't so much that he had a milder tuned motor,  the fact is, his motor was rebuilt the night before and the others wern't. Even his motor was spent after the race, it was running on three cylinders and the cam chain tensioner was toast.

Sam.

[mitchell184]

Hi Everyone

I'm also coming to this thread late in the game (just signed up), but can shed a little light here....

Of the four factory CB750s (not CRs....the CR moniker reflected kitted bikes with kit parts, not whole motorcycles) built back in early '70 for Daytona, only one has been proven to still exist. It's in France, and one of the two bikes shipped there after Daytona for endurance-race use by Honda France.

I have hi-rez images of one (a right-side-shift machine) right after it was uncrated at American Honda in Gardena. The detail of the images is stunning.

Two years ago, Motorcyclist sent Patrick Bodden, Bob Hansen and Bob Jamison to Paris to check on a bike owned by a collector who claimed to have one of the originals...

Although they couldn't confirm it was THE Mann or Bryans bike (or one of the others), they did confirm that various engine and chassis parts of the bike did indeed come from one of the four factory machines. Which is significant considering how elusive this portion of Honda's mechanical history really is.

We've got pix and an amazing bundle of notes on the Paris bike, the trip and the machine in question, and will publish them at some point in Motorcyclist Classic - our new classic/vintage magazine - when we get things organized and the story written in full.

Anyway, I'm in touch with Hansen and various Japanese Honda R&D engineers (who worked on the CB project in the late '60s) on some of the more important details of the story, and we're hoping to lay to rest some of the wild CR/Mann/Replica BS that's been floating around these last decade or so.

Thanks for your time....

Mitch Boehm
Editor
Motorcyclist Classic
Mitch.Boehm@sourceinterlink.com
323.782.2587

[Jerry Rxman Griffin aka MuthaF'er]

Mitch,

Good to have you on board. We'll be looking forward to seeing what you come up with. I didn't see a link to your magazine?!

Jerry

[cafe750]

It's good to have you here Mr. Boehm, and It's great that Motorcyclist is going to be publishing a magazine for us vintage riders. I'll be looking forward to reading it!

[Sam Green Racing]

Hi Everyone

I'm also coming to this thread late in the game (just signed up), but can shed a little light here....

Of the four factory CB750s (not CRs....the CR moniker reflected kitted bikes with kit parts, not whole motorcycles) built back in early '70 for Daytona, only one has been proven to still exist. It's in France, and one of the two bikes shipped there after Daytona for endurance-race use by Honda France.

I have hi-rez images of one (a right-side-shift machine) right after it was uncrated at American Honda in Gardena. The detail of the images is stunning.

Two years ago, Motorcyclist sent Patrick Bodden, Bob Hansen and Bob Jamison to Paris to check on a bike owned by a collector who claimed to have one of the originals...

Although they couldn't confirm it was THE Mann or Bryans bike (or one of the others), they did confirm that various engine and chassis parts of the bike did indeed come from one of the four factory machines. Which is significant considering how elusive this portion of Honda's mechanical history really is.

We've got pix and an amazing bundle of notes on the Paris bike, the trip and the machine in question, and will publish them at some point in Motorcyclist Classic - our new classic/vintage magazine - when we get things organized and the story written in full.

Anyway, I'm in touch with Hansen and various Japanese Honda R&D engineers (who worked on the CB project in the late '60s) on some of the more important details of the story, and we're hoping to lay to rest some of the wild CR/Mann/Replica BS that's been floating around these last decade or so.

Thanks for your time....

Mitch Boehm
Editor
Motorcyclist Classic
Mitch.Boehm@sourceinterlink.com
323.782.2587

Hi Mitch, thanks for joining in on this debate and welcome to the forum.

We were hoping to get some of the team to come on line and try to dispel some of the myths flying about regarding these machines.

Like you said regarding the code name (CB750/CR750), being a factory built machine, it may have been more apt if the factory had badged them RC like they did with all their other facory racers. They might have refered to them as CRs in order to sell the race kit.

In respect of the Paris bike, it's going to be very intresting to see what your findings are, as I know of a person with first hand knowledge  of the four bikes that has seen the said bike and does not think it is genuine.
Does this create another myth

I am looking forward to your article on the Paris CR CB RC 750 in the hope that it does clear up some of the BS that is flying about duck!

Good luck with the magazine Mitch, I hope it is a HUGE success and hope that one of my fellow forum members will procure me a copy.

Regards Sam.

[bwaller]

It's good to hear from you Mitch, and indeed we look forward to the article and the new magazine.

Our man Sam here started this 1970 Daytona discussion and actually has contact with some of the original characters in the UK. He went to considerable work trying to get some of these people to tell their stories here, but it looked like we were "dead in the water" so for his sake (as well as the rest of us) I'm happy you've breathed new life on the subject!

You also have experience wrestling the big CB four around a race track and I enjoyed reading about your exploits a few years back. Whatever happened to that project?

Brent

[Ricky_Racer]

Mitch, I assume bwaller is referring to "Big Benley." Yes, is she still alive and kicking?

Question for this elite group...  I've repeatedly heard mention of strengthening modifications to the early racing CB750 frames.  Were these done and, if so, does anyone know of any document or resource detailing those mods?  Thanks.  RR