Author Topic: 1975 Supersport, performance cafe  (Read 119973 times)

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Offline gnarlycharlie4u

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Re: 1975 Supersport, performance cafe (RS34 dyno work)
« Reply #375 on: July 15, 2012, 10:16:57 AM »

Both curves are nice and smooth, which I attribute a lot of to Mike's head-work, the CR replica pipes, a well matched cam, and getting the intake length properly tuned. What I've also learned is that the bike likes to run about 12.5:1 AFR to really make power.

isn't that the optimum A:F for most efficient combustion of gasoline?

That's some great work you've laid out so far. Thank you.

Offline Doctor_D

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Re: 1975 Supersport, performance cafe (RS34 dyno work)
« Reply #376 on: August 23, 2012, 11:50:47 AM »
The Nighthawk 650 oil cooler was never going to work, because the pipes tuck in too close to the motor to use a sandwich adapter under the oil filter.  But, the oil was hitting 240-250 after a typical dyno session, and not having one seemed like a bad idea.  So, I took a lesson from the CR750 oil cooler setup (and the Bol d'Or bikes) and decided to run the lines up top.

I bought a little Russell oil cooler.  It's small, but fairly deep.  Looks to be a pretty efficient design.



A few hours with the bandsaw and drill press and some hardware store 2" aluminum L-channel was turned into some acceptable-looking bracketry.



Some 45 deg -8AN fittings made for a good fit.  Lines run cleanly through the frame without tight radii or other interference.





I'll have pics of the oil-tank side routing some time this week.
Take care,
David
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1975 CB 750F - Project page: http://forums.sohc4.net/index.php?topic=66026.msg725479#msg725479
1978 CX500
1971 Norton Commando

Offline MCRider

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Re: 1975 Supersport, performance cafe
« Reply #377 on: August 23, 2012, 12:02:41 PM »
Very nice!   ;D
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Offline HondaMan

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Re: 1975 Supersport, performance cafe
« Reply #378 on: August 23, 2012, 12:27:13 PM »
Nice installation!
Does it clear the back of the front fender OK, in full-fork compression? I've sometimes had troubles with dented fenders from these oil coolers. :(
See SOHC4shop@gmail.com for info about the gadgets I make for these bikes.

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Offline Doctor_D

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Re: 1975 Supersport, performance cafe
« Reply #379 on: August 23, 2012, 01:21:20 PM »
Nice installation!
Does it clear the back of the front fender OK, in full-fork compression?

Thanks.

I'm not running a fender (have a fork brace), but it should work fine.  There's a good six-inches between the wheel and the cooler (and only 4" of suspension travel).
Take care,
David
___________________________________________
1975 CB 750F - Project page: http://forums.sohc4.net/index.php?topic=66026.msg725479#msg725479
1978 CX500
1971 Norton Commando

Offline brandEn

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Re: 1975 Supersport, performance cafe
« Reply #380 on: August 23, 2012, 02:02:29 PM »
You gonna make the Isle of Vashon on that beauty this year? Couple weeks away!

Offline Doctor_D

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Re: 1975 Supersport, performance cafe
« Reply #381 on: August 23, 2012, 02:27:58 PM »
Unfortunately, I'm out of town.

In any case, you really want me to kick that thing over on a ferry?

Sent from my ADR6400L using Tapatalk 2
Take care,
David
___________________________________________
1975 CB 750F - Project page: http://forums.sohc4.net/index.php?topic=66026.msg725479#msg725479
1978 CX500
1971 Norton Commando

Offline MRieck

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Re: 1975 Supersport, performance cafe
« Reply #382 on: August 23, 2012, 04:37:12 PM »
I like that woven line David. The stainless line can be a PITA as it is like a hacksaw if it touches anything.
Owner of the "Million Dollar CB"

Offline Doctor_D

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Re: 1975 Supersport, performance cafe
« Reply #383 on: August 26, 2012, 09:58:41 AM »
So here's the other half of the package, buttoned up and oil-tight.

Routing lines through the frame.  Lots of room for a clean run.



Lines where they come into the oil tank.  The 45 deg fitting goes to the engine and the 90 deg is coming from the oil cooler.



Big improvement in clearance and ease of installation is due to the fact that I cut the stock fittings off the tank and replaced they with brazed-on 3/8 NPT bungs.  I was really only able to do this because I had to have the whole bike repainted this summer. (Don't ask... I mentioned it a few pages back.)



Finally, engine side.  Not much has changed here.  Line on the right goes to the cooler, while the one on the left goes to the tank.



Picking up the rest of my repainted parts today, and may even take this thing out for a ride.
Take care,
David
___________________________________________
1975 CB 750F - Project page: http://forums.sohc4.net/index.php?topic=66026.msg725479#msg725479
1978 CX500
1971 Norton Commando

Offline Retro Rocket

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Re: 1975 Supersport, performance cafe
« Reply #384 on: August 26, 2012, 08:31:40 PM »
Nice work as usual Dave... ;)
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Offline Doctor_D

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Re: 1975 Supersport, performance cafe
« Reply #385 on: August 30, 2012, 10:52:58 PM »
Repaint of tank is done.  Hand lettered.  We used Dupont and SEM paints this time and came closer to the stock 1975 color.



The "Supersport" is a little too low, but I wasn't going to have him re-do it.

Here it is on the bike.

Take care,
David
___________________________________________
1975 CB 750F - Project page: http://forums.sohc4.net/index.php?topic=66026.msg725479#msg725479
1978 CX500
1971 Norton Commando

Offline johno

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Re: 1975 Supersport, performance cafe
« Reply #386 on: August 31, 2012, 02:46:29 AM »
Looking really really nice "D"
   Your obviously a perfectionist D but I prefer the lettering where it is ,  makes the honda badge stand out more.  Hope you have a nice day when you take it for a blast.
ciao Johno
GRASSHOPPER SOHC HONDAS ARE THE MEANING OF LIFE.

Offline Doctor_D

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Re: 1975 Supersport, performance cafe
« Reply #387 on: August 31, 2012, 09:57:18 PM »
Everything takes longer than it should.  Completely reassembled the bike today.



Started second kick, then it started spewing oil from the alternator cover gasket.

I took the cover off while the parts were out at paint to install a CB750A field coil for a little better charging, and the gasket looked fine when everything was reinstalled - though obviously not.

Next up, the speedo magnet, which never contacted the forks before, was rubbing.  Nothing about the front end changed, so that's got me scratching my head.

Finally, my fuel filter cracked!  Why and how is beyond me.  Simple repair, but annoying.

Take care,
David
___________________________________________
1975 CB 750F - Project page: http://forums.sohc4.net/index.php?topic=66026.msg725479#msg725479
1978 CX500
1971 Norton Commando

Offline FunJimmy

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Re: 1975 Supersport, performance cafe
« Reply #388 on: August 31, 2012, 11:03:55 PM »
Lookin Cherry.David.
You never see a motorcycle parked outside of a psychiatrist's office!

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Offline 754

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Re: 1975 Supersport, performance cafe
« Reply #389 on: September 01, 2012, 08:53:14 AM »
 Very clean bike there... looks great..
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Offline bwaller

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Re: 1975 Supersport, performance cafe
« Reply #390 on: September 01, 2012, 10:10:37 AM »
Looks great Dave.

Offline raymond10078

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Re: 1975 Supersport, performance cafe
« Reply #391 on: September 07, 2012, 05:59:44 PM »
So glad you upgrade your oil cooler.  The CB650 oil cooler wasn't designed for full flow - at least according to the CB650 Service Manual.  Your engine will be happier with this one.
1978 CB750A (upgrading very, very slowly)

Past bikes - Honda: SL350, CX650C, CB900C, CB1000C, CM450A; Kawasaki: several 1972 750 H2's; Suzuki: TC90J.

Bikes I want: CX650ED, a mid-sized japanese V-twin with ABS.

Offline CBcafeJunkie

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Re: 1975 Supersport, performance cafe
« Reply #392 on: June 15, 2013, 11:42:05 PM »
She's a beaut man good job :)

Offline Greg H

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Re: 1975 Supersport, performance cafe
« Reply #393 on: June 16, 2013, 01:43:52 AM »
I've just spent some time reading all of this thread , and I have to say the end result looks fantastic  8). It's such an inspirational bike ,that I'm off into my garage to do some work on my bike  :D

Offline Doctor_D

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Re: 1975 Supersport, performance cafe
« Reply #394 on: June 16, 2013, 07:38:20 AM »
Thanks folks.  I've gotten it out a few times this spring, and it is a hoot to ride.  Very under-braked for how fast it is though, so I'm making a few changes right now and will post an update soon.

I'm prepping a 1975 GL1000 front end for installation.  I have EBC Pro-Lite rotors for it, rebuilt the calipers with phenolic pistons, semi-sintered pads, and am actuating the whole thing with a nice 14mm radial master cylinder - so it should stop a little better.  As with the the original forks, the GL forks are getting the full RaceTech treatment.  Waiting on a top-triple tree from Dime City and new minus-2" fork tubes from Frank's and they'll go right together.

The small things: new clip-ons, new headlight ears, etc. will come next month - and then we're done for a while. ( I really want to upgrade the swingarm and use a lighter-weight rear wheel and brake - like the Moto one Cycle-X has - but I'm trying to make that a 2014 project.)
Take care,
David
___________________________________________
1975 CB 750F - Project page: http://forums.sohc4.net/index.php?topic=66026.msg725479#msg725479
1978 CX500
1971 Norton Commando

Offline MRieck

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Re: 1975 Supersport, performance cafe
« Reply #395 on: June 17, 2013, 04:56:25 AM »
Yes....you need more brake Dave. ;)
Owner of the "Million Dollar CB"

Offline Doctor_D

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Re: 1975 Supersport, performance cafe
« Reply #396 on: June 17, 2013, 12:13:59 PM »
Yes....you need more brake Dave. ;)

Tell me about it.  Coming down from high double and triple digits is hairy enough when you know you need to brake.

Bike in its current state:
Take care,
David
___________________________________________
1975 CB 750F - Project page: http://forums.sohc4.net/index.php?topic=66026.msg725479#msg725479
1978 CX500
1971 Norton Commando

Offline SOHC4 Cafe Racer Fan

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Re: 1975 Supersport, performance cafe
« Reply #397 on: June 17, 2013, 06:18:18 PM »
Yes....you need more brake Dave. ;)

Tell me about it.  Coming down from high double and triple digits is hairy enough when you know you need to brake.

Bike in its current state:


Freakin' gorgeous, Dave!
1975 CB550K1 "Blue" Stockish Restomod (http://forums.sohc4.net/index.php?topic=135005.0)
1975 CB550F1 frame/CB650 engine hybrid "The Hot Mess" (http://forums.sohc4.net/index.php/topic,150220.0.html)
2008 Triumph Thruxton (http://forums.sohc4.net/index.php/topic,190956.0.html)
2014 MV Agusta Brutale Dragster 800
2015 Yamaha FZ-09 (http://forums.sohc4.net/index.php/topic,186861.0.html)

"There are some things nobody needs in this world, and a bright-red, hunch-back, warp-speed 900cc cafe racer is one of them — but I want one anyway, and on some days I actually believe I need one.... Being shot out of a cannon will always be better than being squeezed out of a tube. That is why God made fast motorcycles, Bubba." Hunter S. Thompson, Song of the Sausage Creature, Cycle World, March 1995.  (http://www.latexnet.org/~csmith/sausage.html and https://magazine.cycleworld.com/article/1995/3/1/song-of-the-sausage-creature)

Sold/Emeritus
1973 CB750K2 "Bionic Mongrel" (http://forums.sohc4.net/index.php?topic=132734.0) - Sold
1977 CB750K7 "Nine Lives" Restomod (http://forums.sohc4.net/index.php?topic=50490.0) - Sold
2005 RVT1000RR RC51-SP2 "El Diablo" - Sold
2016+ Triumph Thruxton 1200 R (http://forums.sohc4.net/index.php/topic,170198.0.html) - Sold

Offline ivanhoew

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Re: 1975 Supersport, performance cafe
« Reply #398 on: June 17, 2013, 11:15:54 PM »
lovely photo.
just do it .

Offline SOHC4 Cafe Racer Fan

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Re: 1975 Supersport, performance cafe
« Reply #399 on: June 18, 2013, 09:07:22 PM »
Thanks folks.  I've gotten it out a few times this spring, and it is a hoot to ride.  Very under-braked for how fast it is though, so I'm making a few changes right now and will post an update soon.

I'm prepping a 1975 GL1000 front end for installation.  I have EBC Pro-Lite rotors for it, rebuilt the calipers with phenolic pistons, semi-sintered pads, and am actuating the whole thing with a nice 14mm radial master cylinder - so it should stop a little better.  As with the the original forks, the GL forks are getting the full RaceTech treatment.  Waiting on a top-triple tree from Dime City and new minus-2" fork tubes from Frank's and they'll go right together.

The small things: new clip-ons, new headlight ears, etc. will come next month - and then we're done for a while. ( I really want to upgrade the swingarm and use a lighter-weight rear wheel and brake - like the Moto one Cycle-X has - but I'm trying to make that a 2014 project.)

Doc,
I'm doing a GL1000 fork swap too.  Can you share where you got the phenolic pistons and EBC discs and details on the parts?
1975 CB550K1 "Blue" Stockish Restomod (http://forums.sohc4.net/index.php?topic=135005.0)
1975 CB550F1 frame/CB650 engine hybrid "The Hot Mess" (http://forums.sohc4.net/index.php/topic,150220.0.html)
2008 Triumph Thruxton (http://forums.sohc4.net/index.php/topic,190956.0.html)
2014 MV Agusta Brutale Dragster 800
2015 Yamaha FZ-09 (http://forums.sohc4.net/index.php/topic,186861.0.html)

"There are some things nobody needs in this world, and a bright-red, hunch-back, warp-speed 900cc cafe racer is one of them — but I want one anyway, and on some days I actually believe I need one.... Being shot out of a cannon will always be better than being squeezed out of a tube. That is why God made fast motorcycles, Bubba." Hunter S. Thompson, Song of the Sausage Creature, Cycle World, March 1995.  (http://www.latexnet.org/~csmith/sausage.html and https://magazine.cycleworld.com/article/1995/3/1/song-of-the-sausage-creature)

Sold/Emeritus
1973 CB750K2 "Bionic Mongrel" (http://forums.sohc4.net/index.php?topic=132734.0) - Sold
1977 CB750K7 "Nine Lives" Restomod (http://forums.sohc4.net/index.php?topic=50490.0) - Sold
2005 RVT1000RR RC51-SP2 "El Diablo" - Sold
2016+ Triumph Thruxton 1200 R (http://forums.sohc4.net/index.php/topic,170198.0.html) - Sold