Topic: CB550 SC Nighthawk 1st Build

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I've been watching Cafe Racer on HD Theater (DirecTV) and I got bit by the bug.

I looked for a CB XXX (anything), found a 1972 CB 400 on craigslist, asked questions, someone else already said they wanted it and I lost it.

Then a bit later I saw this bike, a 1983 CB550 Nighthawk, it ran, but its very dirty, so I took charge of it.

They're supposed to be pretty powerful for their size, and have a 6 speed tranny, DOHC engine, and just a good overall bike.

Parts on the otherhand are tough to come by, I'll have to replace some of the stuff like all the handlebar stuff (gauges, throttle, clutch, levers, the whole deal), the plastic, the headlight, fix the tank, new seat...mostly the stuff I would have replaced anyway.  I wish I had a seat pan though.

I am SO very open to advice.

I think I'd like to do something in Black, Copper (for the shiney parts now) and Tan for others, a black (or Tan) seat with black and white checkers, Black (or tan) with checkers too.  Powder coat the Frame, either Black, or Bronze, new gauges, maybe a one piece aftermarket unit, either a dual headlight or single GIANT headlight.

So I begin my first project and look forward to this forum and all you PRO's...great bikes on here...

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I've taken the carbs offf, the exhaust pipes, the wiring harness and the hand controls.

Now I'm preparing the seat pan.

I've got a 4ft by 3ft 20 gauge steel sheet to use, it's about 1MM thick.

I'm going to have a slight curve around the back.

I plan on covering the whole thing in foam, then leather, no metal will be showing.

The front part of the seat on the factory bike went on top of the rear part of the tank, and I may do the same too.

I have an original seatpan that I shaped to be a bit flatter with a heat gun.  The plastic gets just warm enough to mold and reshape without bubbling.

I plan on incorporating a typical rear hump but I want the seat to be big enough to hold the occasional passenger.

If anyone has seen the Koppa Kafe bike, that's going to be my inspiration.

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Engine is finally out.

I've been ziplock bagging stuff so hopefully reassembly will go easily.

Rear end, and Front end, a little cutting then off to the powder coating.

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Now for some polishing.

The Stator cover, distributor cover, and valve cover.

The valve cover has before and after parts on it.

I'm only done with the first rough cut, and have an hour or more per part for the finish polish.

I'm tempted to buff in a checkerboard square with a machine finish, and polish finish.

[MoMo]

You are right about the Nighthawk series of bikes being good motorcycles, and powerful for the size. A fun, stylish, light handling bike that makes an excellent commuter. Seems like you have a good plan, and have fun with it...Larry

[Little_Horse]

I had a 450 sc good little bike for a first bike. The sc's are not a typical cafe bike but that doesn't mean you can't go for it.

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Thanks for the comments guys.

The 550s were the cruiser version, but I noticed when I took out the fork springs there was a 4 inch spacer.

I took that out and the front end came down just where I wanted it, must be because the 650s used the same forks but was less cruiser style and more standard style.

I hope by taking off that bulky rear end seat, that I loose enough weight to bring up the power to weight ratio.

[Little_Horse]

that is the wrong way to lower a bike and is potentially very dangerous. The spacer is what the designers put in the forks to control pre load, adjusting the size of it some is ok. Taking it out is not. I would say a half in out at most but even that will cause the forks to be spongy and not operate at the right height. As you have it now it will bottom dangerously and easily, please save us from having to read about that and put them back in. You can lower the forks an inch further into the trees as one ok method but this is problematic if you go too far beyond that as it tips the scales to the dangerous side in regards to the safe amount of trail. I would suggest you google motorcycle suspension and geometry basics so you can get a better idea of all the variables.

[Roach]

whats that second bump on the cam cover for?

nice build was going to get one just before i found my cb550 but the one i got was in parts so it was dirt cheap

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Thanks for the tip little horse. I'll verify the fork specs for the 650 before I ride.

I did push the forks up first, but it looked dorky...if that's the best way to do it then dorky is better than dead.

I'll try to reduce the size so I can have 1, 2, or 3 inches drop with pushing the fork tubes up too then add clip-on bar ends to the part sticking up.

That should get me somewhere.

The clymers manual is pretty good so I'll go back to it and remind myself on the fork springs and spacers.  It does have air preload on it though. So the spacers seemed more to increase the length of the fork more than anything.  I do know I can't screw up the trail which I have yet to measure, so I'll remember go do that b 4 my 1st ride.

Thanks

[Little_Horse]

The thing to understand about the difference between what the air adjust does vs the spacer is the space is your course nob adjustment and the air is for fine tuning the setup. At least this was the idea. I never have liked the air I prefer just standard style forks, also there is probably a reason newer bikes don't have them.

 Back to the point though the spacer/pre load changes where the forks operate in their range. The designers made it to operate between two points to eliminate bottoming as well as fully extending at the wrong moments so its range is specific to a certain measurement. This is called sag, the manual will tell you how to check this and adjust it. Sometimes depending on your weight and the condition of the springs a different/new spring needs to be put in so that you can get the sag back into range. All this has been mastered over years of motorcycle design so there is not really any real chance that you will find better success by going your own way. It may work if you could call it that but it wont work better.

When you drop the forks you haven't changed the sag at all by the way and that is one reason its the prefered method to lower the bikes some also it helps to make the bike tip in with less force into corners so for some its a free and useful trick.

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Have you seen the site that describes moving some of the spacer at the bottom of the tube?
Here is one: http://www.calsci.com/motorcycleinfo/Suspension2.html

Some folks cut the springs, what do you think about that? or put in shorter springs, or both shorter and stiffer springs?

I'm in total agreement with keeping it safe and doing it in a proven way.

[Little_Horse]

that article is basically about messing with pre load again. You might consider looking into a shorter fork from a different bike if the ride height is that important to you.

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I've taken to the tank and removed the rust and primer and frankly I'm thinking of keeping it this way.

My intent with the tank is to have a leather strip running down the center 5-6 inches wide with a black and white checker board.

Now here is the tough choice, polish the whole tank...

Leave it as it is, but do a better job at a machine finish...

do a part machine finish and part polish...

I'm also thinking of leaving the very few minor dents in the tank..

comments/suggestions

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Well I've got the frame finally painted, and I went ahead and did the fork tubes too.

Why Paint versus powdercoat?

Well the paint was cheaper and I could get it to match the engine and any other parts easily.

I didn't have the energy to get the tools required to remove the rear swing arm or the tripple clamps, so this time around I went with what I could afford and still look pretty good.

I did duplicolors Gloss Black engine enamel over their rust proofing primer on the frame, and paint only on the fork tubes.

After it's had a couple weeks to dry, I'll color sand it.

I was going to plate the tank, but the platers can't do it, so I'm back to filling and painting it with copper accents on the sides, and possible a copper strip across the top, with copper plated gas cap.

I included a couple shots, an older one when I got it, the frame and forks after painting. Not the best shots, but it turned out alright, I think.

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I'm going with a copper and black theme.

The frame has gotten it's 4th coat of paint, the engine it's third...now I'm waiting for the front fender, and the rest of the engine covers to come back from the platers to come back.

I need to clear coat the frame and engine, then put stuff back together.

I have a problem with one of the exhaust bolts, it's broken and won't come out no matter ho much WD40 I put on it.

Does anyone have a recommendation?

I have a small propane torch that I m thinking of using to heat up the block and hope it frees it up.

[Really?]

whats that second bump on the cam cover for?

 

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Parts back from the plater....everythng except the front fender
Valve cover
Clutch cover
alternator cover
stator cover
Gas tank cap


Frame is now getting powdercoated, the painting worked until I applied the clearcoat. 
There must have been solvent or something still in the paint even though I gave it weeks to dry.
It just turned into alligator skin, so it wasn't expensive to paint, nor expensive to powdercoat.

[Option13]

Wow, that plating looks great! Looking forward to updates.

You know, Nighthawks do have their own forum. If you have any questions, the guys down there ought to be able to help you out.

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Tank pictures....I'm doing the frame too with the copper look.
My friend from work did the painting.
http://bennerairbrushing.blogspot.com/

The paint is from Alsa Corp, it's their Copper Crazer...

[Little_Horse]

I like that copper paint, looks really good. Is the base color around it black?

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base color is black with silver pinstriping.

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Tank Done
Frame Done
Just a few more parts left and I'll be completely ready for reassembly.

[MoMo]

haven't caught your thread for awhile-coming along nicely. I like the copper and black, especially the copper motor parts.  Keep up the good work...Larry

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thanks larry.  its slow mostly cause i'm battling with a bad health issue, that keeps me down often.
i appreciate all the support i can get.

i cant wait to ride.

next year i'll re-do the entire engine and fit up any loose ends, but i just want to get riding this year.

plus my boys like helping so i want to keep the project busy too.