rear brakes

[Darwin_R65]

OK nothing like finding only a single problem when something goes wrong. And this is nothing like that.

I've reassembled my rear wheel after greasing the spline with a moly grease, and go to adjust the rear brakes and "click" the brakes lock on. back the brakes all the way off and the wheel eventually frees up and then repeat and same thing.

Pads look a little worn but nowhere near enough to be a problem.

But the shoes don't really seem to sit on the cam as snugly as I would expect.

My bikes manufacture date is 10/1980 and looking at pictures and catalogues that state the brakes changed 09/1980, it appears I have the right shoes.

Could this be my cam is worn? Aftermarket shoes made by dodgy brothers?

Anyway it results in If I apply the rear bake firmly, they lock on and stay on, as the cam rolls too far around.

Or is this the way it's all meant to be set up and maybe my drum has been skimmed a little too much  over the years?

John

[Ed Miller]

The lower shoe looks like it's not installed right.  Can you post a pic showing both pivots at once?  I thought the shoes had different ends.

[montmil]

Maybe this photo will help?
http://www.motobins.co.uk/displayfinal.php?function=show&subs=102b&title=BRAKE+SHOES%2FSPRINGS

[nhmaf]

Here is a pic of my rear brake shoes installed - one thing I noticed is that one can end up with the ends of the shoes that pivot on the common "bolt" (toward left/bottom of pic) a bit misaligned in which they don't properly pivot and might  either bind up or not travel properly.

IT does look like your cam is a bit worn from the photo, though I don't know if it is too worn.. hmmm.

[aussie]

Umm - IMHO I think it is time to replace the cam... and I agree with Ed - the ends don't look quite right either.

[Ed Miller]

Is it possible to get the two shoes mixed up?  I don't remember.

nhmaf's bike must be an LS....  

[nhmaf]

Yup, mine is an LS, but I think it is mechanically identical, save for the larger diameter.   There IS a top shoe and a bottom shoe - otherwise the overhang isn't correct to mate with the cam, which is supposed to engage in one direction and disengage in the other.   I don't think that I can get mine reversed top-bottom, but if I could then it would try to disengage when you stepped on the brake and engage when at rest ?

[drewboid]

The cam should not be able to pass the end of the shoe. It could be the wrong cam if the final drive was replaced, the cam could be worn, or the shoe could be bent (unlikely).  Ordering a new cam would be my first move.

[Bob_Roller]

In the first set of photos,there is a difference in the shoes.

There is a difference in the length of the straight section of metal that contacts the cam, one is significantly longer than the other.

Looking at the installation on the LS, both shoes look to be the same dimension.

I would suspect an incorrect part, or more likely at some point in time some 'adjustment' has been made to the lower shoe.

[nhmaf]

I think that Bob may be on to something - perhaps if you could take your shoes off and examine them for part numbers ?   I am thinking that maybe a PO had replaced the bottom shoe with one for an LS (which take a slightly bigger shoe as the rear hub area is slightly larger in diameter).   If the lower shoe end were a bit shorter it might not go past the end of the cam - it's a thought anyhow..   But, the ends of the cam in Darwin's picture do appear to be more worn down than in mine also.

[Ed Miller]

According to the motobins site posted above, the LS has different shoes than the regular R65s, and the pictures of the regular R65s were like the ones in Darwin's pictures.  I'll be changing tires in a few weeks, but I don't feel like pulling my rear tire for a look until then.  Sorry.  My bike is only a month newer, so I bet I'll have the same brakes as Darwin.

[MrRiden]

Those are LS shoes in NHMAF's pic.  [stare and compare] They are positioned correctly [top & bottom are slightly different]
rich

LS Shoes

[nhmaf]

I guess that I shouldn't have assumed that a pic of mine would help anything !  I do know that the LS shoes are slightly "bigger" due to the differences in the rear wheel (snowflake .vs. LS)  housing diameter, but I thought that the relative sizes from top/bottom where the same as compared to the snowflake wheels, but that is my bad, I guess.

[Rob Valdez 79 R65]

A few pictures from my '79.  Click to make them larger:

[nhmaf]

Compared to Rob's pics, the ends of the shoes on Darwin's bike don't seem to be in the right place?   Maybe they are the wrong ones, or that cam is really worn down?