Author Topic: Nighthawk 550 Bobber/Chopper, kinda  (Read 53730 times)

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Offline tomsweb1

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Re: Nighthawk 550 Bobber/Chopper, kinda
« Reply #76 on: October 04, 2009, 08:58:46 PM »
yes both of my 550sc's had that problem.
Present: 1978 CB750A, 1978 CB400A, 1983 Nighthawk 550, 1984 CM250C

Past: 1977 XL100, 1982 KZ1300


pikeymick

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Re: Nighthawk 550 Bobber/Chopper, kinda
« Reply #78 on: October 09, 2009, 03:02:24 PM »
I've been getting lots of work done lately. Got the forks apart and I'm trying to replace the seals now. Anyone know the stock fork oil for these?

Offline Alan F.

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Re: Nighthawk 550 Bobber/Chopper, kinda
« Reply #79 on: October 09, 2009, 03:57:44 PM »
Clymer says Dexron ATF 375cc or 12.7oz each leg.
-Alan

pikeymick

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Re: Nighthawk 550 Bobber/Chopper, kinda
« Reply #80 on: October 09, 2009, 04:09:44 PM »
Do you know what weight though?

Offline Laminar

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Re: Nighthawk 550 Bobber/Chopper, kinda
« Reply #81 on: October 09, 2009, 05:02:05 PM »
I'm not aware of Automatic Transmission Fluid having a certain "weight" rating. You can pay out the ass for special fork oil or you can buy cheap ATF that will work just as well.

pikeymick

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Re: Nighthawk 550 Bobber/Chopper, kinda
« Reply #82 on: October 09, 2009, 05:51:41 PM »
Oh I didn't know you could use ATF. Isn't fork oil only 10 bucks a bottle? I guess that's a little more than ATF.

But I guess it doesn't really matter at this point. I got the forks apart and the right fork had a big gouge in the stanchion tube, then when I pushed all of the diarrhea that was in it, out, (which was fork oil, water, rust, and dirt) I found the tube is friggin bent... #$%*.

Anyone have a line up on a right fork? Or know what tubes will fit in this triple trees. Hmmm I was thinking about replacing the trees anyway, looks like I might be putting a new front end on there.... damnit.

pikeymick

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Re: Nighthawk 550 Bobber/Chopper, kinda
« Reply #83 on: October 09, 2009, 06:10:43 PM »

 >:(

 >:(

 >:(

 >:(

 >:(

 >:(


Would one of you guys be willing to measure the length of your forks from center of axle to the top of the upper triple (or top of tube if the tubes aren't flush)? Thanks... need to find a fork....
« Last Edit: October 09, 2009, 06:16:59 PM by pikeymick »

Offline Alan F.

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Re: Nighthawk 550 Bobber/Chopper, kinda
« Reply #84 on: October 09, 2009, 06:28:34 PM »
I had a gouge like that on my 750K3 when I first did the forks, there was a ton of water in there too.

The first thing that comes to mind is a complete front end swap from a twin cam 650 nighthawk 83-85

Oh and one of the cool things I've heard about using atf in forks is that it makes the seals swell a little preventing leaks and actually improving the situation.
I'm gonna give it a shot on my CM400 project when the time comes.
« Last Edit: October 09, 2009, 06:30:21 PM by Alan F. »

Offline Laminar

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Re: Nighthawk 550 Bobber/Chopper, kinda
« Reply #85 on: October 09, 2009, 06:42:17 PM »
From the top of the upper tube (not including the cap), I get 32 5/16" to the center of the axle with the bike on the centerstand.


The '82 Nighthawk had 37mm fork tubes. Snatch these up and combine the shipping:

Fork tubes

Calipers

Rotors

No guarantees that the brakes would bolt up perfectly and you'd have to figure out a wheel but then you'd have dual fronts for not a lot of money.

pikeymick

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Re: Nighthawk 550 Bobber/Chopper, kinda
« Reply #86 on: October 09, 2009, 07:01:42 PM »
Done. Well at least I have the seals.

Offline Alan F.

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Re: Nighthawk 550 Bobber/Chopper, kinda
« Reply #87 on: October 09, 2009, 07:13:24 PM »

pikeymick

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Re: Nighthawk 550 Bobber/Chopper, kinda
« Reply #88 on: October 09, 2009, 07:15:20 PM »
Pretty nasty huh! I kind of saw it coming. I went to take the cir-clip out and the thing snapped in two. Thanks for your help, you guys are saving my butt!

Offline Alan F.

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Re: Nighthawk 550 Bobber/Chopper, kinda
« Reply #89 on: October 09, 2009, 07:18:49 PM »
An early CBR/hurricane front end will be my choice when I get a 550SC.

pikeymick

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Re: Nighthawk 550 Bobber/Chopper, kinda
« Reply #90 on: October 16, 2009, 09:25:38 PM »
Alrighty. The forks are ordered but the guy who I bought them from is dragging their @ss on shipping the items. So in the meantime I've been working on other stuff. But before that I want to apologize because I'm not good at taking pictures. I just end up working the whole time and not wanting to stop to take snapshots.

Here is the seat. I took the original seat pan and cut the back off of it. It looked like it would be the perfect chopper shape.


I ordered the seat foam from the oceankayak website others on the site have mentioned.







I sanded the cut edges smooth and then covered it with fleece, and then set the vinyl in the sun to warm up then smoothed it out, and stapled it onto the seat pan. I like how it came out.




I started fabricating the rear fender. I started out by stretching some fleece over the rear wheel.


I covered the fleece with Polyester Resin.


From this I'll split the fender down the middle, I'll widen the fender to match the frame width, and then glass up the space in between. Should be sweet.


I've also started painting. Here is the front wheel


And the tank... which I could've put a little more bondo effort into... see the big dimple with a small dab of material in the dent... yeah. Me too.
« Last Edit: October 16, 2009, 09:34:45 PM by pikeymick »

Offline Alan F.

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Re: Nighthawk 550 Bobber/Chopper, kinda
« Reply #91 on: October 17, 2009, 07:15:41 AM »
But before that I want to apologize because I'm not good at taking pictures. I just end up working the whole time and not wanting to stop to take snapshots.
Not at all, the pics are good and the writeup is informative.

I'm really liking the chopped seatpan, I'll probably do something like that with my CM400 seat but it's got a steel pan so I'll have to figure a way to attach the cover...

I'm gonna be watching your fender construction too, it's very interesting to see new stuff like that!  I've been wondering how to make some good lightweight fenders for my CM400 and you've hit the nail on the head.  What's this fleece from? and what resin are you using, where can I source these items?

It's looking very good, Cheers!
-Alan

Offline kerryb

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Re: Nighthawk 550 Bobber/Chopper, kinda
« Reply #92 on: October 17, 2009, 11:15:14 AM »
Nice job on that seat!  It looks like it will be quite comfortable.  A very novel construction method for a fender.  I look forward to the end result.  Are you planning fiberglass cloth for strength at some point?
intrigued by the wail...seduced by the scream.

Offline mystic_1

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Re: Nighthawk 550 Bobber/Chopper, kinda
« Reply #93 on: October 17, 2009, 11:49:59 AM »
+1 to all of the above.  Seat looks good and a stock pan is a sure bet for fit to your frame.  I will also be watching your fender project with interest!

mystic_1
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My build thread:  http://forums.sohc4.net/index.php?topic=68952.0

pikeymick

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Re: Nighthawk 550 Bobber/Chopper, kinda
« Reply #94 on: October 19, 2009, 09:10:47 AM »
Nice job on that seat!  It looks like it will be quite comfortable.  A very novel construction method for a fender.  I look forward to the end result.  Are you planning fiberglass cloth for strength at some point?

Yeah fiberglass to widen and strengthen it. Then a layer of bondo to smooth it out for painting.

pikeymick

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Re: Nighthawk 550 Bobber/Chopper, kinda
« Reply #95 on: October 27, 2009, 10:48:32 AM »
I hope this goes to a new page... too many pictures on the old one messes with the loading.

I'm still waiting on the forks I bought on ebay. It's going to be an interesting complication. The forks were off of a 1982 Nighthawk 650, which was an SOHC. The front wheel and rotors are a completely different design than the '83 NH 650. What I'm hoping is that the tabs for the calipers will be in the same location and that I'll be able to use the calipers I have from the '82. So the front end will be thus: '82 NH 650 forks and calipers, '84 NH 650 front wheel with CBR600F2 rotors (same parts number as the front wheel). The forks should be in soon... the seller really dragged his feet in shipping them...

In other news. I got the Clutch MC up and running. Bled the system. The clutch lever feels good, but I can't get the clutch to fully engage yet... I'm guessing it's a little stuck from sitting. I think the Slave Cylinder might be slightly leaking as during bleeding I setup a gravity feed for the brake lines and it would pull air bubbles, but the air wouldn't be in the line on a subsequent bleed cycle. I took the slave apart (it was filled with crystallized brake fluid) and cleaned the crap out of it. I wet sanded the surfaces with 1500 and then buffed em up a bit. They felt smooth to the fingernail, and not pitted. The local stealership didn't have the parts (when I called them they said they had them.... hmmmm).

I abandoned the previous fender idea. I didn't like the shape with the seat. I instead mocked up a frame that matches the lines of the seat and looks a little more sporty. I glassed up a mold of that, now I'll make a finish mold from this one and then the final pieces. I'm looking at integrating a new tail light as well. Probably an LED from a sport bike as the old one won't give me enough clearance to the tire. I'm looking at a clear alternatives light on ebay.

I re-bonded the gas tank a little, and repainted. I've left the black theme on the curb and opted for a silver paint scheme. Not sure how I feel about the overall look with the black, chrome, and silver. But the paint came out really well, despite the tank not being in great shape. I did a full wet sand spectrum up to 1500, and then used some rubbing compound and the paint really feels smooth!

The drag bars I originally went with (as pointed out by you guys) didn't work at all... there just wasn't enough clearance with the tank. I've put on a raised bar (Dirt Bike style). I sourced a new front brake MC from a GSXR 600, and its a sick looking piece! It has a shorty race lever on it, which I love.

I've met a bunch of the neighbors as I'm out there everyday before and after work. I already love this bike more than any other I've ever owned, and I haven't ridden it for more than 50 yards, hahahaha.

I'll get some pics up soon!

Offline Alan F.

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Re: Nighthawk 550 Bobber/Chopper, kinda
« Reply #96 on: October 27, 2009, 12:33:51 PM »
Sounds like a good mix of parts you've got there, when you know just what fits would you write up a quick how-to for my documents page? (link is in my signature line)
-Alan

pikeymick

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Re: Nighthawk 550 Bobber/Chopper, kinda
« Reply #97 on: October 27, 2009, 12:35:28 PM »
Sure thing!

Offline Alan F.

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Re: Nighthawk 550 Bobber/Chopper, kinda
« Reply #98 on: October 27, 2009, 03:49:57 PM »
Thanks Man, if you need any costom bits made up give me a shout maybe I can help.
-A

pikeymick

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Re: Nighthawk 550 Bobber/Chopper, kinda
« Reply #99 on: October 28, 2009, 06:26:54 AM »
But before that I want to apologize because I'm not good at taking pictures. I just end up working the whole time and not wanting to stop to take snapshots.
Not at all, the pics are good and the writeup is informative.

I'm really liking the chopped seatpan, I'll probably do something like that with my CM400 seat but it's got a steel pan so I'll have to figure a way to attach the cover...

I'm gonna be watching your fender construction too, it's very interesting to see new stuff like that!  I've been wondering how to make some good lightweight fenders for my CM400 and you've hit the nail on the head.  What's this fleece from? and what resin are you using, where can I source these items?

It's looking very good, Cheers!
-Alan

Just saw this Alan. The fleece is your basic fleece fabric. It's great for stretching around awkward shapes that regular fiberglass just wouldn't be able to conform to. The resin I used is Polyester Resin, I bought it from TAP Plastics in El Cerrito, the town over. But there is a better manufacturer online, but I can't think of the name of the company... couldn't find it in a quick search. I'll post it when I get the info. The fleece you can get from Jo Ann Fabrics or any fabric store, or cut up an old fleece jacket. The only problem with the fleece is it is very brittle so you have to layer it up with glass.

The forks came in yesterday! As I started taking them apart I got a little worried when the fluid was coming out brown... but there wasn't any water mixed in so that was good. I got them apart and Epic win, they had progressive springs! These were on a distant wish list. I changed out the seals for good measure, and bolted them up. The calipers look like they should match up with the rotors so I went ahead and ordered the rotors from an old CBR that denniskirk.com had on the parts list for new rotors for a DOHC NH 650.

The wheel spacing is slightly off, about a 1/8". I looked at the parts mircofiche and all three bikes have the same part number for the wheel spacer. It must be a combination of differences in the speedometer ass'y (the DOHC bikes share the same part number but not the 82 NH) and differences in the diameter of the bottom part of the forks.