Topic: 1977 CB550F IDK (first build)

[minimo]

Part ID help , please. Winner gets a meal at In-N-Out (ehem, goldarrow).




I think this came off the back of the bigger front brake pad, as it seems to sit pretty snug in there:

I don't see it in the parts diagram and the replacement brake pad didn't come with it...

[goldarrow]

The black rubber looks like caliper piston seal, white plastic goes between the piston and the brake pad

[minimo]

The black rubber looks like caliper piston seal, white plastic goes between the piston and the brake pad

Hmmm. The black part in the pic is not the piston seal - it is smaller. There's a slight groove or step around the inner circle that mates perfectly with the white plastic ring - makes me think that these two parts are a component that I'm almost certain went between the piston and the pad.
You'll see the old piston seal pictured here at the base of the piston:

I don't see other seals in any of the break-out diagrams online, and obviously the piston seal sits in the groove of the inner caliper wall. Maybe the black/white part was once a component to the old brake pad? It would sit perfectly in the way that I have it pictured above, between the piston and the underside of the brake pad...

[minimo]

But goldarrow, you seem certain that ONLY the white plastic ring is what sits between the brake piston and the pad. Notice in the last pic a residue seen on the underside around the inner circle of the old brake pad; evidence of what appears a nice fit for the white ring part. So, you may be right (and maybe owed two Double-Double hamburgers now) and maybe it's just purely coincidence that the mystery black seal fits perfectly around the white ring?

Meanwhile, just to try it out I fitted the part as you see in the photo in my previous post (black seal around white ring) and it feels/looks as though it puts too much pressure against the pad. I'll pull the black seal off this time and see if it's a better fit.

Bleeding out brakes. Good times.

Oh, I also ordered this to rub in the brake piston cavity and piston seal. Hope it's the good stuff that will keep these parts from rusting/corroding too much:

[goldarrow]

Some of my bikes has that white plastic on the pad, not the black seal, that's why I thought the seal is for piston seal. 

[minimo]

Hmmm... The white plastic ring came on some of your bikes but not all, right, goldarrow?
Well, I installed only the white ring this time and the pad is still rubbing on the disc, regardless of caliper adjustment. But I doubt pulling out the white ring will make any difference since it seems to rest flush around the center protrusion (underside of pad). I don't doubt the disc is not true but the rubbing is consistent on full rotation meaning there's too much pressure coming from one side (or both). What else could it be? The pads are rated correctly for CB550F 75-77. Possibly bent or bowed forks/stanchions?
Well, I'm going to try pulling it anyway and see what happens.

[goldarrow]

Try pushing the piston all the way in and work on the lever to push it out

[minimo]

Try pushing the piston all the way in and work on the lever to push it out

"Lever"? If anything, don't I want to push it IN and not OUT?
I've tried to make sure the piston is pushed in all the way; I farted the air out of it by pressing it with a vise sandwiched between some flat metal pieces... With the white ring in place between the pad/piston, there's a slight protrusion of the pad at the mating surface (this is the limit no matter how hard I try pushing the piston in all the way).
Let's see if the pad becomes flush when I pull the white ring out... Standby

[minimo]

I probably should have taken a photo before pulling out the white ring but the pad protrusion looks/feels the same.


Meanwhile, it might be worth mentioning that the pad on the other side can be rocked/teetered between the pry point down below and the split pin hole at top. The pad not being aligned here could have something to do with the rubbing... Is there a correct way to press fit the pad in on this side of the caliper?



Because I'm bored, I'll try fitting the front brake back on now that I've pulled the white ring and see if that made any difference. Oh yay

[minimo]

Rats. Still rubbing. I'm kinda all out of ideas other than allowing the rub to just wear down normally on rides...
Bleeding the brakes again to fit the white ring back in. Whew, what great progress today 

[goldarrow]

I'm thinking somewhere along your caliper mounting bracket misaligned when everything is mounted?

[goldarrow]

Here's pic of calipers when mounted with wheel, photo is of 750, but should be similar on 550

[minimo]

Thanks for the pic, goldarrow. Yeah, that's about what I'm aiming for.
So, I put the white ring back in between the piston and the pad. I'm taking heed of your advice and I've loosened all the fender mounting and brake caliper adjuster screws to readjust alignment. See how it goes. I may only have time to loosen all the bolts for today and carry this on another day :sigh: Thanks for chiming in, goldarrow.

[minimo]

Got something going now.
Turns out I had the fender brace/caliper hanger installed wrong. To get it right, I basically switched them around so that the caliper hanger is sandwiched between the fender brace and the fork leg. With some adjustment of the caliper screw, the pads are no longer rubbing on the pad. Phew.
Progress finally?

[goldarrow]

No rush, no pressure, but let see it running this summer???

[minimo]

That's the goal, goldy! Thanks for your support! In-N-Out awaits!

[Restoration Fan]

Meanwhile, it might be worth mentioning that the pad on the other side can be rocked/teetered between the pry point down below and the split pin hole at top. The pad not being aligned here could have something to do with the rubbing... Is there a correct way to press fit the pad in on this side of the caliper?

On my 78, there's a cotter pin that goes into that small hole there to hold this pad in place.  Yours doesn't appear to have it here.

Part # 25 shown in the photo below. 
25  PIN, COTTER (1.6X22) part # 94201-16220

[minimo]

Yeah, thats the COTTER PIN and I do have it in the pic - the pin legs flare out of the body of brake pad B.

Meanwhile, it might be worth mentioning that the pad on the other side can be rocked/teetered between the pry point down below and the split pin hole at top. The pad not being aligned here could have something to do with the rubbing... Is there a correct way to press fit the pad in on this side of the caliper?

On my 78, there's a cotter pin that goes into that small hole there to hold this pad in place.  Yours doesn't appear to have it here.

Part # 25 shown in the photo below. 
25  PIN, COTTER (1.6X22) part # 94201-16220

[Restoration Fan]

Yeah, thats the COTTER PIN and I do have it in the pic - the pin legs flare out of the body of brake pad B.

OK, my bad.  I can see the head of it now.  Tired eyes late at night and I wasn't seeing it.

[minimo]

The workings of something battery box-ish...


It's still a little loosey-goosey.
Figuring out some ears to slot into the center stand bracket. Probably cut some L pieces and rivet those onto the battery box frame. We shall see...

[minimo]

So it's a tad crude but I'm calling the battery mount done (at least before paint). I hope I have clearance for the swing arm. Gulp.

[SOHC4 Cafe Racer Fan]

So it's a tad crude but I'm calling the battery mount done (at least before paint). I hope I have clearance for the swing arm. Gulp.

Done for now.  I bet you might revisit that to simplify the compartment.

[minimo]

I agree, CB750 Fan. This is my first time mounting it with the battery. It is pretty solid but I can already see what I can edit out (ie the top frame of the battery mount...).
I'd like to nice-up the center stand mounting ears... Or I can just paint the whole thing black and fuggedaboudit.

Any suggestions?

[minimo]

Something like this actually feels good.
Meanwhile, I like where it's positioned. I'm pretty confident that it'll clear the swing arm. Here's a side view:

[SOHC4 Cafe Racer Fan]

Bummer, your pictures are not displaying (only an X).

My thought from what you have fabricated is that it is a little large.  I can see the need to get it secured firmly.  Another consideration, maybe for IF you revisit the design is what type of battery are you running.  If you are using a lithium ion, it will be smaller and MUCH lighter than a gel battery. 

Personally, I am hesitant to run a battery next to the swingarm, since it will have some exposure to elements and I don't want my battery or terminals exposed to water (rain, wet road, etc.).  I imagine this is why you tried to "contain" the battery with a case.