Topic: CB750K2 rear brake engages with passenger

[754]

Is the front still mounted to tye original mount.
 On dirt bikes the brake anchor is often mounted to frame not swingarm. The way I read about it, said less chance of lockup, while going over bumps..

[MCRider]

Is the front still mounted to tye original mount.
 On dirt bikes the brake anchor is often mounted to frame not swingarm. The way I read about it, said less chance of lockup, while going over bumps..

That's right. That's what BMW did with their streetbikes. Our CBs have the brake stay affixed to the swingarm. This causes the brake plate to track with the swingarm rather than the frame, making the brake rod get tighter or looser even though the pedal pressure is constant.

What happens is that we sub consciously compensate with the pedal pressure.

[754]

What really bugs me is that we cant figure this one out....so far..

[hotelstationery]

Thanks for all the replies.  It's winter now so it was cold and dark when I got home last night so I wasn't able to have a look in the light or take pictures.

Cant' tell but did you line up dimples on the arm and on the shaft?

Dimples?  On the brake arm and corresponding shaft that comes out of the drum?  I never had them off, so I'm not sure.

Can you shoot a picture or two of the pedal area?

Yes.

IMG_20141108_081355964 by JeremyIllingworth, on Flickr

IMG_20141108_081406737 by JeremyIllingworth, on Flickr

Do you have stock exhaust?

Yes.

And from what's been reported here lately, seems 40 year old shoes are coming apart from age.

I checked mine and they are not coming apart.

I wonder if his "six turns out" is six full turns or 6 clicks. 3 full turns is within the range I'm speaking of.

You're right, turns actually was clicks.  Six was also an estimate, it was dark and cold and late and I just wanted to get it working.  It's not like I turned it one click at a time and tested it, I just did that many and it was good.  For all I know one or two clicks would have been enough.

i just looked at the pics again, and didn't see the small splined washer/dust cover that has the little indicator arrow stamped

Me neither.  It looks like I need a DUST SEAL, BRAKE CAM 43134-300-000

IMG_20141108_081457129 by JeremyIllingworth, on Flickr

Unfortunately I don't have a garage but after the bike is cooled down I can roll it into the basement.  I checked all the fasteners and they are all tight and I don't see any parts touching that shouldn't be.  While I don't know everything about what may have happened over the last 42 years, it's a well kept, stock bike that just crossed over the 40,000 mile mark.

I think it's mostly in the adjustment since I cannot find anything 'wrong' with any of the moving parts.  When I measured the inch of travel I was using a combination square that I had to hold in my hand as it wasn't long enough to stand up on the ground.  I will try again with a ruler that is on the ground.  When you guys do yours what do you do?  Do you look for the faintest grab at an inch?

The hardest part of this is going to be finding volunteers to sit on it and compress the springs.

jeremy

[MCRider]

On the pics, we need to see the end of the pedal spindle and the end of the cam in the brake plate that the 4" arm is on. A straight on shot, not at an angle.

#2: Do you look for the faintest grab at an inch?

The manual saying 1" is another example of a manual's many short comings. The adjustment will always be a compromise of what works for you, the shoe/boot you wear, the load on the bike etc.

[hotelstationery]

On the pics, we need to see the end of the pedal spindle and the end of the cam in the brake plate that the 4" arm is on. A straight on shot, not at an angle.

IMG_20141108_161806619_HDR by JeremyIllingworth, on Flickr

IMG_20141108_161820208 by JeremyIllingworth, on Flickr

Now that I've taken some close up pictures I can see where the dimples are and they are pretty lined up, maybe one tooth out.

Do you look for the faintest grab at an inch?

That's what I did.  What is everyone else doing?

The manual saying 1" is another example of a manual's many short comings.

One of my shortcomings is that I frequently take things literally.  I said one inch and so it was done.

The adjustment will always be a compromise of what works for you, the shoe/boot you wear, the load on the bike etc.

I think that is the solution to this problem, I just need to find an adjustment that works for me, which is riding solo most of the time.  I don't expect to have another passenger until spring.

jeremy

[MCRider]

Yeah you got it. he first pic dimples are fine. I can't make out the 2nd pic. But you see what we're getting at.

[Henning]

Is the actuator rod (see picture) oriented correctly? The curve needs to follow the roundness of the swingarm, or else they _will_ interfere with each other. It shouldn't be necessary to fiddle with the adjustment so much.

This is true for the K1; I see you have a K2, which uses a different rod.