'75 CB550K1 Gulf - Round...3, the fun stuff

Re: '75 CB550 Gulf - round two

Holy Crap Chris! Just when I thought this bike couldn't get better...


I love the lines of #2! I have been itching for a fairing'd cafe bike. I can't wait to see how this turns out! Following this for sure!
 
'75 CB550 Gulf - round two

Agree with the above. Full fairing is pure bike porn. Please please build it.
 
Re: '75 CB550 Gulf - round two

Soooooo, I really hate to say this, but I've decided to scale way back on this bike this winter. My life's going to be a bit hectic over the next few months, and I seriously doubt I could finish everything by riding season. Plus, I got a late start to "building season" because I was laid up for a couple months with a work injury.

There is however a little cb200 that's been waiting patiently in my shop for a year now, and I figure I can churn out a quick simple little pit bike with that one.

I will however install a fork brace, and hopefully a second front disc on the 550. Oh and a petcock rebuild... And the oil leak from the neutral switch...

Next winter though...game on.
 
Re: '75 CB550 Gulf - round two

Bummer Chris. But I feel it's safe to say we understand.

I do think you will be surprised on how much fun that 200 can be.
 
Re: '75 CB550 Gulf - round two

Sad to hear you won't be doing it this winter but totally understand. However, I'm really looking forward to seeing you work on the 200.
 
Re: '75 CB550 Gulf - round two

You suck Chris!









Just kidding of course. It's not like you don't have an awesome bike to ride without touching it!
 
Re: '75 CB550 Gulf - round two

so where is this 200 thread? I need links! hahaha. You would have even more fun if that was an rd200.
 
Re: '75 CB550 Gulf - round two



Wha.....? The stars are all crashing out of their orbits now. It is a grey, grey world...

Just kidding man! I am stoked to see what you can make out of the little guy! We need to get together and make up some carbon fiber stuff!
 
Re: '75 CB550 Gulf - round two

Being a college student these days I totally know how you feel.
 
Re: '75 CB550 Gulf - round two

Things have slowly started happening lately. Mostly just parts arriving, but progress nonetheless.

The fork brace arrived today. I'm...not thrilled with the fit and finish. It doesn't clear the stock fender, as advertised. I guess that'll just require a carbon fender. Shucks. ;D

The finish is pretty bad too. It's cast aluminum, and what I assumed was an anodized finish...but it rubs off on my fingers. Very powdery :eek: I'm planing on filing down the casting marks and bead blasting it.

brace.jpg




Glenn (revheadgl as he used to be known here) drew up this neat image for me. Tentatively planning on doing a machined clamp-on brace for the swing arm. A carbon fender will bolt to that too. I've started shaping the plug for the chin fairing, which will be carbon as well. That should be pretty straight forward; should, but things rarely go as planned.
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I also received 3 yards of 5.7oz 2x2 twill carbon fiber.
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Dyna S ignition is also on the way. And I'm currently trying to find an 18x3.5 40-spoke alloy rim for the rear. Swapmeet dug up a 19x2.5 alloy for the front, so if I can find a rear, they'll be going on with new rubber. (I hate the Avon Roadriders currently on the bike) Dunlop GT501s are what I'd like to put on. I ran them on a little xs400, and they were really great tires.
 
Re: '75 CB550 Gulf - round two

I forgot to add that I finally found a cheap GSXR750 wiring harness (back half had burnt up). I was able to steal a very specific connector from that and will be able to power the steering damper now. The K8 GSXR750s came with an electronic steering damper. It just clamps down a valve when given power, so if I wire in a switch I can have light or heavy damping.
 
Re: '75 CB550 Gulf - round two

Carbon is easy.... Now I hate you too. ;-)

I'm interested in your comments about Avon Roadriders too. I tend to think of 501s as being an eighties tire that's well past its use by date and Roadriders as being a good tire - from all the comments on the interwebs. But you don't like them. Is it a grip issue (compound) or tracking (pattern and sidewalls) or the way it feels (contour)? Is it perhaps that they don't suit that particular bike? Tell me more - please.
 
Re: '75 CB550 Gulf - round two

Ringo said:
It just clamps down a valve when given power, so if I wire in a switch I can have light or heavy damping.

Interesting system. Wonder if you could make it electronically adjustable?
Looking forward to seeing the new bodywork... ! Its going to transform that beauty.
 
Re: '75 CB550 Gulf - round two

teazer, it's mostly a grip issue, as far as I can tell. I had the rear skip and slide around during aggressive riding this summer. It's hard to compare these tires to the gt501s because both bikes were set up quite differently, but I perceived much more grip with the Dunlops. They also wore faster.

I also had issues with the tread profile. I don't know if I'm describing this right, tires aren't my forte. But when you look at the tire head on, the curve of the tread is much more pronounced in the rear than the front. It looks like I'm trying to squeeze too big a tire on too small a rim, even though I matched the stock sizes as closely as I could. In the front, nearly all the tread is usable (1/8" chicken strips, not that I care about the things, but for educational purposes...) and in the rear, they are wider than 1/2". The last 1/2" of tread is basically unusable. I could see a wider rim fixing this, but... on the 400 with Dunlops I was running a wider tire than the Avon on the same size rim, and chicken strips were equal, or at least proportionate for the tire size. Hope I explained that well enough, let me know. Here's a pic that clearly shows the difference between front and rear: (click to enlarge)
gulf-1.jpg
 
Re: '75 CB550 Gulf - round two

Dale, t71ford and I were talking about making it variable. Space for switches and dials is a big issue, plus I've opened quite the can of worms with this bike and am really trying to keep it simple to ensure it's back together by spring! It's definitely something to look into down the road though.
 
Re: '75 CB550 Gulf - round two

teazer, I should also add that it could very well be a combination of factors. I know I had tons of fork flex last summer. And a fair amount of frame and swing arm flex as well. I'm going to try bracing the front and rear, and reevaluate from there. The cartridge emulators also need more tweaking before the bike gets back on the road. I don't foresee actually swapping rims and tires until mid-summer or fall, so I should be able to sort out the combined issues. Maybe the tires won't be as big of an issue as I had thought.
 
Re: '75 CB550 Gulf - round two

What size tire and rim are you using? Yes, too wide of a tire will give you an "oval" profile rather than the preferred "round" profile. Curious too as my experience tells me you already have the better tire (Avons AM26 or any AM series over the GT501s).

Regardless of your other chassis issues, the "too wide" tire is an issue in itself that only adds to your other problems. You already know that you're not using all of the tire's grip compared to the front. It's a not a lean angle issue because of the front's wear pattern. For a given bike lean angle, both tires should be at the same lean angle. If the rear is not wearing to the same place at the front, then it's profile is different.
 
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