Topic: '75 CB550 rebuild, working toward cafe racer.....

[SOHC4 Cafe Racer Fan]

Looking good.  I might lose the rear fender and bob the front one, but that's just me.  Great job on the seat.

[sinister902]

front fender already bobbed, just no pics of that yet lol. I MAY still ditch the rear fender, but not sure just yet.

[kerryb]

I was looking at my rearset ideas last night as saw a potential problem with clearance on the kickstart lever.  How far do yours stick out, are they behind the lever when it is in the horizontal position? 
Yes the fender looks good with that seat, what do you plan for tailight/lic plate light?

Nice job on the seat,
kerry

[sinister902]

I actually haven't checked clearance with the kick starter, but the pegs flip upward, so I don't foresee a huge problem there....as for tail light, signals, and plate/light....I think I'm going to use a cat-eye tail light with the plate bracket on it from ebay, and a set of small signals also from ebay. Those are the last bits I need to buy for the build, and grips....then its just paint and re-assembly.

[sinister902]

Just realized I never popped back in here with "finished" pictures. long story short I got impatient and tossed the bike together quickly to get a riding season in. I have since decided to break her back down and put some attention back into the finer details of the bike and really clean things up now that I have my essential fabrication and everything pretty set. going to repair some things, change some things, and some adjustments. I'll be back at this thread regularly when I get to work again.

for the time being, here are some of the pics from last season.




(ignore my friend daryl sneaking a middle finger in that picture, my appologies.....but I think its an otherwise nice angle of the bike)

[sinister902]

Thread back from the DEAD! I decided to tear back into this thing and make some more changes/updating. I snagged a great deal on a '78 CB750 Super Sport dual disc front end and a few other misc parts.

-Clip on handlebars
-headlight ears
-newer dual-disc compatible brake master cylinder
-carb rebuild kits
-Headlight brow
-build new exhaust from scratch

Going to also re-position the rear-sets because after putting some miles on this thing I found the riding position left some more to be desired, so I am going to move them higher up the frame rail to get my knees centered in the tank.

tore down the front end:



new front end parts



forks in




bars on



headlight on






now that its together, I think my initial thought that the bars would be best above the trees was the wrong idea for the stance.....I think I need to pull it back apart and get the clip-ons below the top tree to get the front view to look proper.

[Roach]

i think the bars look fine...but what i would do is heat up the mirror with a torch and bend it down so it doesn't stand up so high.

[fastbroshi]

So you used the whole 750F swingarm, brake, and rear wheel assembly?

[sinister902]

So you used the whole 750F swingarm, brake, and rear wheel assembly?

yes, just pulled the swingarm bolt off the 750 and transfered the whole assembly to the 550 and re-installed the swingarm bolt. painless.

the front on the otherhand has been "interesting". I only had the forks/calipers/lines, so I used the stock 550 wheel and two 550 rotors. I broke the speedo drive trying to modify it to fit the dual discs, and then the caliper brackets rub the rotor when installed on the forks. I had to use a file to add clearance in the notches for the rotors on the mounting brackets, and then use washers to center them over the rotor. It was a pretty long process of checking clearance, filing, checking clearance, filing, etc.. over and over until no rubbing. I rebuild my carbs last night, and hope to have the bike running and tuned up after work today. just have to re-mount the controls, finish welding the new mounting tabs for the rearsets, and bleed the front brake system. I'd like to get a few miles on it and then tackle my exhaust project.

[fastbroshi]

In case you want to do it again or if you just want a precisely machined adapter, Rangelov is selling some adapters so you don't have to mod the stocker.  I've got one and it's perfect. 

[sinister902]

Thanks for that tip fastbroshi, IIRC they were something like $40....which is a little too much for me to spend right now....I think I may cut down to one gauge with the digital speedo modded into the housing like Little_Horse did on his. I'll have to PM him and get some more details on how he did it.


But back to the build!
Few pics of the peg mounts I made

[sinister902]

got everything back together and rode for about an hour yesterday. Some things of note with the 750f front end swap....

-the caliper hanging brackets need more clearnace in the cutout for where the rotor sits between

-you need to add a couple washers between the mounting bracket for the calipers and the forktubes to get proper spacing

-the 550 fender can be used if you drill new holes to hang the front half of the mounting flanges

-you need a vacuum bleeder to get the front brakes bled (which I still have not done)

now that I have everything on, the riding position is FAR more confortable than before, but I have some details to attend to. I need to get MUCH shorter throttle cables, clutch cable, and a shorter brakeline from the master to the distibution block for the front brakes. I think I am going to stop at that point for this year to enjoy riding it, and over next winter take it totally apart to paint and polish everything to make it a REALLY nice bike.

[fastbroshi]

Cool, we'll keep our eyes peeled.  Did you ever happen to measure how long that 750F swingarm is?  I'm curious as to how it compares to the stocker.

[Bunicula]

really enjoyed this read.. going to be a great referance point to look back on starting my build. id love to pick your brain a bit on how you shaped your seat and rear section. Did you use and template to build from? any insight would be awesome dude 

[sinister902]

Fastbroshi- When I did the swap, I measures the swingarms and they were the EXACT SAME LENGTH. My rear came off a '76 supersport, and my front end came from a 78 supersport.

Bunicula- the seat fairing is the old gastank that was rusty and leaky. I eye-balled it and cut it into the shape you see. I started out hand drawing the curve for the sitting portion and cut that out, then trimmed until I liked the curve. Then I split the hump in half to narrow it down. I absolutely love the end result....when you look straight down the back of the bike, it carries the curvature of the stock tank all the way down the bike....as in the front of the tank starts wide, and narrows toward the seat....the cowl pics up where the tank leaves off and continues narrowing to the rear fender. I think it is the perfect line for the bike using a spare tank for the seat, you can't screw it up haha.

[sinister902]

well, I can't leave anything alone. I snagged a spare lower triple clamp to make my own clip-on bars with.....the ones I bought left alot to be desired... the downward angle was far too shallow, and I wanted them welded ahead of the tube instead of off the side of it (you'll understand what I mean in a second)

Step one, cut up triple clamp


step two: lean bar onto brick for hilbilly-angle setter lol...then weld.


You end up with this:






I also lowered the front about a half inch and raised the rear a half inch to level out and get the stance I wanted. Really enjoyed putting some miles on it today.

[GV1390]

Bump.

[sinister902]

Bump.

LOL. I'll start a new thread once things get moving again. pics of a disassembled motor ain't worth posting yet. Fun to see where I started, though