Lionel Brancquart's CBX

CBXs, new bikes, old bikes, cars, trucks, general chat, off topic, this is the place to post it.
Rick Pope
ICOA Rally Director
ICOA Rally Director
Posts: 2270
Joined: Wed Sep 03, 2003 3:16 pm
Location: Lawrencburg, IN
Location: Lawrenceburg, Indiana

Re: Lionel Brancquart's CBX

Post by Rick Pope »

.<<but questions why I would bother when I could buy a newer used sport bike for less and will still perform better...>>

I came to that same conclusion. Never regretted buying the CBR-XX.
Rick Pope
Either garage is too small or we have too many bikes. Or Momma's car needs to go outside.

Larry Zimmer
ICOA Web Post/Pix/Video Archive Mgt
ICOA Web Post/Pix/Video Archive Mgt
Posts: 2196
Joined: Mon Dec 15, 2003 2:32 pm
Location: Brighton, MI
Location: Brighton, Mich
Contact:

Re: Lionel Brancquart's CBX

Post by Larry Zimmer »

Best reason I can think of for doing it is -------- just 'cause!!! :D Guys just wanna have fun!
Larry Zimmer
cbxlarry@sbcglobal.net

User avatar
Syscrush
ICOA Member
ICOA Member
Posts: 1714
Joined: Fri Sep 14, 2012 2:29 pm
Location: Toronto, ON
Location: Toronto, ON

Re: Lionel Brancquart's CBX

Post by Syscrush »

wyly wrote:but questions why I would bother when I could buy a newer used sport bike for less and will still perform better...
From that perspective, the CBX has never made sense - even before launch. Irimajiri himself said:
Shoichiro Irimajiri himself, designer of CBX and the GP racing sixes RC-165-6, admits that when, during CBX development, a four-cylinder 1000 was evolved from the company’s DOHC endurance racer, "It was extremely light and actually much faster than the CBX. Nevertheless, we felt there was something exhilarating and exciting about the 6-cylinder CBX that was lacking in the 4-cylinder CB1000F... something in the CBX that could not be measured in numbers like speed and weight, (something that) made it a very sexy machine."
I am on the list of people who think that modding these bikes for outright performance doesn't make sense - but some of the best things in life don't make sense. :lol: If motorcycle decisions were to be based on logic, we'd all be on one of these abominations:

Image

what astounds me most about the Brancquart cbx is the claimed dry weight, 174kg-382lbs :o where/what did they remove to lose 160lbs? http://survincity.com/2015/12/cest-bon-cbx/
I agree that that number stretches credulity. Suppose they cut 10 kilos from the engine with the light crank, rods, and other internals. And another 20 kilos with forged magnesium wheels and modern brakes, suspension is probably a wash, say another 10 kilos for the exhaust, frame is probably a wash with the bob cutting weight but surely some bracing added. Maybe 10 kilos for removing all lights, alternator, lead-acid battery, and some wiring. Suppose 5 kilos by replacing all fasteners with Ti or other lightweight options. It's hard to see how you get to ~70-80 kilos cut.
Phil in Toronto
A cool guy deserves a cool bike, a dork needs a cool bike...
Pics of Perry, my '79.

EMS
ICOA Member
ICOA Member
Posts: 10151
Joined: Wed Mar 05, 2003 7:55 am
Location: North East OH, ICOA 3904

Re: Lionel Brancquart's CBX

Post by EMS »

Syscrush wrote: From that perspective, the CBX has never made sense - even before launch. Irimajiri himself said:
Shoichiro Irimajiri himself, designer of CBX and the GP racing sixes RC-165-6, admits that when, during CBX development, a four-cylinder 1000 was evolved from the company’s DOHC endurance racer, "It was extremely light and actually much faster than the CBX. Nevertheless, we felt there was something exhilarating and exciting about the 6-cylinder CBX that was lacking in the 4-cylinder CB1000F... something in the CBX that could not be measured in numbers like speed and weight, (something that) made it a very sexy machine."

As someone who has followed Honda's racing and development history closely, I have always been curious about this "so-called quote".

The CBX was unveiled in 1977. Supposedly, the development took a tad less than 2 years. That means, they were working on the CBX in 1975 (???)
Honda's DOHC endurance racer did not hit the tracks until the early 80s
The story that Honda looked both at a 4-cyl 1000cc and a 6-cyl CBX during the development stage is totally made up, IMO.
Honda was very determined to develop an inline six because they knew of Kawasaki's effort to bring out an in-line six and needed to beat the competition badly. Of course, they would never officially admit to this. Industrial espionage is not something to admit to.
The CB1100F was a watered-down street version of the CB1100R endurance racer (which itself was based on the CB900F) and did not come to market until late 1982 as a 1983 model. It was never really "developed" by itself as a 4-cyl 1000cc and could not have been a "considered alternative" to the CBX.

User avatar
Syscrush
ICOA Member
ICOA Member
Posts: 1714
Joined: Fri Sep 14, 2012 2:29 pm
Location: Toronto, ON
Location: Toronto, ON

Re: Lionel Brancquart's CBX

Post by Syscrush »

EMS wrote:The CBX was unveiled in 1977. Supposedly, the development took a tad less than 2 years. That means, they were working on the CBX in 1975 (???)
Honda's DOHC endurance racer did not hit the tracks until the early 80s
The story that Honda looked both at a 4-cyl 1000cc and a 6-cyl CBX during the development stage is totally made up, IMO.
Honda was very determined to develop an inline six because they knew of Kawasaki's effort to bring out an in-line six and needed to beat the competition badly. Of course, they would never officially admit to this. Industrial espionage is not something to admit to.
The CB1100F was a watered-down street version of the CB1100R endurance racer (which itself was based on the CB900F) and did not come to market until late 1982 as a 1983 model. It was never really "developed" by itself as a 4-cyl 1000cc and could not have been a "considered alternative" to the CBX.
As someone who spends a bit too much time posting Snopes debunking links on my family's FB posts, I thank you from the bottom of my heart for this.

With your analysis, I agree the claims that this was a quote from Irimajiri don't really hold up. Also, George Carlin didn't say that stuff about tall buildings and short attention, nor did the Pope say that stuff about it being OK to be an atheist. :lol:
Phil in Toronto
A cool guy deserves a cool bike, a dork needs a cool bike...
Pics of Perry, my '79.

EMS
ICOA Member
ICOA Member
Posts: 10151
Joined: Wed Mar 05, 2003 7:55 am
Location: North East OH, ICOA 3904

Re: Lionel Brancquart's CBX

Post by EMS »

There is a book in the making by a renowned motor-journalist which deals with the fast progress and excess of motorcycle technology in the Superbike era. It incorporates a lot of document research and interviews with contemporary industry members. It will debunk quite a few myths about why and how the leading motorcycle manufacturers did things in the post 1969 era.
He picked 1969 as a starting point because of the dawn of the "Superbike" with the Honda CB750 SOHC, BMW /5 and Kawasaki 2-stroke Triple.
I felt honored to be able to provide some of my own record collections accumulated over 50 years of being a motorcycle enthusiast.

User avatar
wyly
ICOA Member
ICOA Member
Posts: 1727
Joined: Tue Oct 30, 2007 4:20 pm
Location: calgary alberta canada
Location: Calgary Canada

Re: Lionel Brancquart's CBX

Post by wyly »

Syscrush wrote:
I am on the list of people who think that modding these bikes for outright performance doesn't make sense - but some of the best things in life don't make sense. :lol:
true enough, I do things that aren't logical performance or financially wise...it's just fun...
If motorcycle decisions were to be based on logic, we'd all be on one of these abominations:

Image
mrs wyly would actually love that for a commuter...then she'd have to stop complaining about those "three bikes in the garage"
I agree that that number stretches credulity. Suppose they cut 10 kilos from the engine with the light crank, rods, and other internals. And another 20 kilos with forged magnesium wheels and modern brakes, suspension is probably a wash, say another 10 kilos for the exhaust, frame is probably a wash with the bob cutting weight but surely some bracing added. Maybe 10 kilos for removing all lights, alternator, lead-acid battery, and some wiring. Suppose 5 kilos by replacing all fasteners with Ti or other lightweight options. It's hard to see how you get to ~70-80 kilos cut.
maybe the weight of 382lbs given in the article was a misprint, I'd still be impressed if it was 482lbs...but until someone else comes up with another verified number I'll accept the 382 lbs as stated...
CBX a work in progress, still improving...GS1150EFE completed and awaiting modifications.....RD350, remnants in boxes scattered throughout the garage

guyem
New Member & Happy To Be Here
New Member & Happy To Be Here
Posts: 3
Joined: Wed Apr 18, 2018 1:04 am
Location: France
Location: France

Re: Lionel Brancquart's CBX

Post by guyem »

Hi everybody ,
I made the ignition of Brancquart CBX and other ones , below the link of Guy Lauverjat CBX sound at a maximum of 11000 t/mn

https://www.youtube.com/watch?v=zUbSOKdJtno&t=56s

Engine is stock except : ignition , exhaust , suzuki bandit carbs , oil pressure , oil cooler , compression ratio , AAC
more informations and pics below

http://allumage-electronique.blogspot.f ... yl-gl.html

For the Brancquart CBX , an essentiel part you don't see on my blog is the very lightweight crankshaft

User avatar
Syscrush
ICOA Member
ICOA Member
Posts: 1714
Joined: Fri Sep 14, 2012 2:29 pm
Location: Toronto, ON
Location: Toronto, ON

Re: Lionel Brancquart's CBX

Post by Syscrush »

guyem wrote:Hi everybody ,
I made the ignition of Brancquart CBX and other ones , below the link of Guy Lauverjat CBX sound at a maximum of 11000 t/mn

Engine is stock except : ignition , exhaust , suzuki bandit carbs , oil pressure , oil cooler , compression ratio , AAC
more informations and pics below
Thank you VERY much for checking in. The info about the Brancquart machine is much appreciated, and that Lauverjat bike sounds wonderful too.

I have never heard of Bandit carbs on a CBX - can you share some info about what was done and how?
  1. Were they OEM Suzuki Bandit carbs (which I think are Mikuni CV carbs), or were they flatslide or roundslide aftermarket carburetors made for the Bandit and adapted to use in the CBX?
  2. Were they arranged in a straight line or V shape similar to stock?
  3. Did you keep the stock intake manifolds from the carbs to the head, or something custom?
Je peut essayer d'ecrire en Francais si c'est meilleur pour vous, mais je pense que votre Anglais est meilleur que mon Francais. :lol:

Thanks again!
Phil in Toronto
A cool guy deserves a cool bike, a dork needs a cool bike...
Pics of Perry, my '79.

Dynamohum
Forum Regular
Forum Regular
Posts: 120
Joined: Sat Oct 28, 2017 3:24 am
Location: California
Location: California

Re: Lionel Brancquart's CBX

Post by Dynamohum »

guyem wrote:Hi everybody ,
I made the ignition of Brancquart CBX and other ones , below the link of Guy Lauverjat CBX sound at a maximum of 11000 t/mn

https://www.youtube.com/watch?v=zUbSOKdJtno&t=56s

Engine is stock except : ignition , exhaust , suzuki bandit carbs , oil pressure , oil cooler , compression ratio , AAC
more informations and pics below

http://allumage-electronique.blogspot.f ... yl-gl.html

For the Brancquart CBX , an essentiel part you don't see on my blog is the very lightweight crankshaft
How was the compression ratio modified if the motor is still stock?

EMS
ICOA Member
ICOA Member
Posts: 10151
Joined: Wed Mar 05, 2003 7:55 am
Location: North East OH, ICOA 3904

Re: Lionel Brancquart's CBX

Post by EMS »

Dynamohum wrote:
How was the compression ratio modified if the motor is still stock?
Excellent question 8) 8) I know a lot of people who have no idea what compression ratio is and how it is determined. You see it all the time, when someone sells a "big bore" kit with stock dome appearance pistons and they claim "stock compression" :roll: :roll:

User avatar
CBXTRA6
ICOA Member
ICOA Member
Posts: 523
Joined: Sat Mar 22, 2003 1:25 am
Location: Kernersville , NC
Location: Kernersville, Nth CAROLINA

Re: Lionel Brancquart's CBX

Post by CBXTRA6 »

Merci Emmanuel (Guyem) pour ta contribution !

Excellent links and information on your ignition and tuning !
Besides Guy on track footage, this U Tube link is an absolute "caviar" for the ears :

https://www.youtube.com/watch?v=92pZD5t ... e=youtu.be

As far as Dynamohum pertinent question, correct me if I'm wrong, but I don't think you meant to write that the engine
was stock because obviously it is not after changing :
<< ignition , exhaust , suzuki bandit carbs , oil pressure , oil cooler , compression ratio , AAC (THESE MEANS CAMSHAFTS) >>

Did you mean to say that the stock displacement was left at the same bore ( CC ) but with higher compression pistons ?

The increase in power and RPM band is not surprising in view of what was done to this 1045 cc engine !

- I agree with many of your remarks in your web page, when you mention how sensitive ignition tuning is on the CBX, I know because I have experienced it too with my mechanic friend, and had to re-set completely after installation of a Dyna S module, and the timing was way off before.
- However, I don't know why keeping the stock coils which are NOT good and most often cracked with age... there are better options on the market now.
- You are also correct in pointing out how sensitive the 6 is with oil temp. ! It affects greatly the performance of the engine.
- As for the rest, it is a "no brainer" when you swap for better & bigger carbs tuned with the right exhaust...

As for the Brancquart bike, I had a chance to discuss it with Lionel Brancquart himself and his friends at the SRC a few weeks ago, and while it sounds farfetched to see a CBX engine reving between 18 & 20,000 rpm, I got to say that this engine only has the look and engine cases of a standard CBX... there are so many mods that it defies imagination ! Lionel and his Dad built this bike more as a challenge to push the envelope as far as possible... and they did ! I saw the bike up close and it is a master piece !

Great work ! :text-goodpost:
JP

EMS
ICOA Member
ICOA Member
Posts: 10151
Joined: Wed Mar 05, 2003 7:55 am
Location: North East OH, ICOA 3904

Re: Lionel Brancquart's CBX

Post by EMS »

CBXTRA6 wrote:Merci Emmanuel (Guyem) pour ta contribution !

Alors, Jean-Paul: Help me out with my rather poor French here. When would you say "merci pour ton contribution" ???

EMS
ICOA Member
ICOA Member
Posts: 10151
Joined: Wed Mar 05, 2003 7:55 am
Location: North East OH, ICOA 3904

Re: Lionel Brancquart's CBX

Post by EMS »

Never mind, JP! After going through a couple of issues of my "Asterix et Obelix" collection, it all came back. It is the gender of the noun not of the person, that determines the form of the possessive pronoun. 8) I think I deserved my bad grades in French. :oops:

User avatar
CBXTRA6
ICOA Member
ICOA Member
Posts: 523
Joined: Sat Mar 22, 2003 1:25 am
Location: Kernersville , NC
Location: Kernersville, Nth CAROLINA

Re: Lionel Brancquart's CBX

Post by CBXTRA6 »

EMS wrote: I think I deserved my bad grades in French. :oops:
:laughing-lettersrofl:
JP

Post Reply

Return to “Daily Discussion: By, For & About CBXers”