[CaTacL1sm]

That's more suited to an SOHC 750. Given the era and body style of the 80s 750s, it's going to be an uphill battle to achieve that look. The easiest way (and comparable in cost) would be to pick up a running SOHC 750... then you'll have tons of period stuff that bolts right up

 

[TrialsRider]

T.... I've seen the aluminum billet intake manifolds for the CB750. are they worth it or should I stick to rubber?

One of the reasons for using rubber to mount a carburetor is isolation from vibration, too much vibration in the float bowls causes problems, no idea if that would become a problem on your bike, just sayin.

 

[TrialsRider]

couple of chicken scratch ideas. First Conceptual look;
View attachment 96167

front brake looks a little weak


... full fairings usually have to let some engine casing parts stick out the sides on a Honda 4
too wide in the hips.

 

[CaTacL1sm]

Hmmm... what about an 80s style dustbin

 

[Teazer]

Dustbin fairings were banned from racing is the mid fifties - not the eighties.

I realize the sketch is just to get an overall idea as to how it might look and that looks right for a 72 CB500 and looks out of place on a DOHC which is much larger and ungainly. I love all sorts of bikes from different eras, and to my eyes, the only way that a DOHC looks good is as a Freddie Replica type. It can have late model forks and wheels but looks best with the "look" from that era of AMA Superbike racing.

 

[jcw]

View attachment 96167

Anyone actually see one of these or a replica in person? Not me...
I agree, I've seen plenty of 500's cruising around Cali with this type of fairing. Very tidy looking.


From http://www.mcnews.com.au/barber-vintage-motorsports-museum-pt3-phil-aynsley/

The Barber Vintage Motorsports Museum - Main Racing Hall

Four factory Honda CR750s were raced at the 1970 Daytona 200 with Dick Mann winning the race on one. American Honda later made an extensive 200 piece “Race Kit” available through a few selected dealers to convert a CB750 into a CR. This is one of those “Kit Bikes” painted as Mann’s bike.


https://www.motorcyclistonline.com/blogs/dick-manns-1970-daytona-200-victory-mann-machine#page-13

 

[XB33BSA]

I DARE YOU
to not be a simpering copycat,by copying all the horribly done shit you have seen
like pods
why are you and everybody else so queer for pods ?
you know why ? because you are a copycat,yeah ,i know,right ?
you do know that only the large really large expensive pods will allow you to not loose hp everywhere in the rpm range
short stubby small surface area pods are such a stupid thing to use for any carburetor
see an engine is not sucking in air
it is creating a lower pressure than atmospheric pressure(ABOUT 15PSI)
the outside air ,the atmoshpere is simply doing what comes natural and equalize pressure
that is what creates weather on earth that is the wind part
so you have air trying to rush in with not much energy
anything that restricts the flow to not be easy,costs some air
with an airbox there is a nice straight stream of air flowing in the port
the rubber boot at the back of the carb is an extension of the length of the intake port
the air coming in when channeled nicely has energy of its own simply because it is a moving column
when the intake valve closes this energy is halted with a bang and a reverse SOUND energy wave goes backwards up the port untill it hits the atmospheric pressure
then asnother bang and another bang
all while the port is closed at the speed of sound waves of sound energy are bouncing off the closed valve and reflecting back up the port
the length of this total port including the rubber velocity stack to the airbox
that length and the intake cam duration determines the top end hit of power
higher rpm shorter length
pods shorten tuned length as well as fucking with sonic waves

 

[jcw]

that X on the headlight btw, it's retarded...

 

[jcw]

This is cool. Like a harley dirt tracker.

 

[TrialsRider]

while where at it.and the number plates are gay

Not if that's his actual competition number,

mine is #51 numbers are suppose to be minimum 1 inch wide strokes and a minimum 4 inches high

 

[TrialsRider]

Hmmm... what about an 80s style dustbin

I predict that is going to be the next big cafe racer fad:|

 

[TrialsRider]

View attachment 96167

View attachment 96173

Anyone actually see one of these or a replica in person? Not me...
I agree, I've seen plenty of 500's cruising around Cali with this type of fairing. Very tidy looking.


From Barber Vintage Motorsports Museum Pt3. | Phil Aynsley | MCNews.com.au

The Barber Vintage Motorsports Museum - Main Racing Hall

Four factory Honda CR750s were raced at the 1970 Daytona 200 with Dick Mann winning the race on one. American Honda later made an extensive 200 piece “Race Kit” available through a few selected dealers to convert a CB750 into a CR. This is one of those “Kit Bikes” painted as Mann’s bike.


https://www.motorcyclistonline.com/blogs/dick-manns-1970-daytona-200-victory-mann-machine#page-13

That sh*t right there is exactly what we all really wanted to be riding in my day.

 

[TrialsRider]

that X on the headlight btw, it's retarded...

lol but aren't you worried about it suddenly exploding on impact.

 

[TrialsRider]

i know you dont ride your street bike with numbers/ plates on it, i dont know of anybody who road races that have numbers on a roadbike, big fox paw

True that.


I rode my MV wearing my spandex trials suit once, lol people were shouting 'pop a wheelie!' when I rode by, it totally sucked.

 

[CaTacL1sm]

Dustbin fairings were banned from racing is the mid fifties - not the eighties.

I know, but imagine how wild an 80s dustbin would look

 

[XB33BSA]

interesting histireical tidbit
the dick mann 750cr factory daytona special used honda xl250 type sliders
4 studs 4 nuts at each axle carrier clamp
i see the kit bike there has got the 2 stud type
yeah and that fairing is a beautiful and ill bet pretty slipery design

but i actually favor this
was that a rob north lashup ?

 

[CaTacL1sm]

you know, you could totally run a mailbox type fairing on the street if you get an LED light bar that would fit perfectly in the mail slot... then you could even tint it black (provided the light is bright enough) so that it would look full race spec

 

[tjurek51]

that's it. that's what i'd like to do, for the most part. i'm not much on the history of the sport, mind you. still learning, so you all sharing this is great! my pic is just a mash up of ideas from various posts. Mostly from a variation of the MotoGuzzi style bike of the same era. YES, a stretch from that to a 80's CB750 F, but wanted to start with some ideas. Here, btw, are some ideas on changes and reinforcements. your thoughts are appreciated.



for those who may recognize these ideas, I want to make sure I reference the project and give credit to the guys who did this. i'm not going to go to the extents they did, but I figure these mods are proven (by now)

https://www.bikeme.tv/index.php/dons-cup-gold-ultimate-honda-cb900f/

several questions still abound, like wider wheels, better forks or just mod what I have, etc.

 

[TrialsRider]

...

https://www.bikeme.tv/index.php/dons-cup-gold-ultimate-honda-cb900f/ ...

Note the caption under the photo of that front frame brace "These used to break when you hit a tree at 180km/h."
That's about right; imho unless people are fracturing the stock frames somewhere they are just guessing those brace points are beneficial.

Wider tires on their own are of little value compared to an upgrade to radial tires from bias tires, radials are available in fewer sizes and they are typically wider then the older tire tech.

 

[jcw]

Wow. What a build.

He basically re-engineered the entire bike. Can't even imagine how much he spent. If the machine work cost anything close to what I paid, that bike probably cost as much as 2 V4S Ducati.

Guess that's what an unlimited budget buys you. All for 118hp...

View attachment 96191



IMO, bracing is good. This is based on what was braced on frames from the period (from the factory's subsequent models and race teams), my own FEA work on my frame, and some small wire models I constructed. The welding looks like quality work. You would do well to copy that.
One area that didn't make sense to me was this.

View attachment 96189

Not sure why he wouldn't just extend a single diagonal piece to the upper right corner instead of part way.

There is still a segment unbraced in the center of the frame from where the top center backbone connects to the side rails to where the subframe starts. Forces through the frame will seek out the weakest point, and to me that's it. Put it in a computer and run a FEA and it will flex here.

Extending the X brace behind the frame as forward as you can helps tremendously. But you run into airbox clearance problems right away.


Here is what I did...