Topic: excessive brake travel

[78whiteorbs]

got a 78cb750 K8 almost on the road. Back brake pedal seems to have mucho excessive travel before stoping the back wheel. Shoes look good to my eyes, adjusted the brake rod nut all the way in but still the pedal goes way further than it should. Any ideas fellas?

[scottly]

Pictures would help, but my first guess is the brake arm needs to be removed and reinstalled offset by one spline, so the end of the arm is further rearward.

[SohRon]

It sounds like you may not have the pedal installed correctly. Check for index marks like in the following pic...

[78whiteorbs]

thanks for the picture, I will check that out. It is way off and travels like 5 inches maybe . When i first got the bike it was stuck and upon removing the wheel everything looked to be in good shape just a little corrosion that I sanded out. I tried just moving the arm and not the pedal with the rod off and it travels a few hours on the clock. I know these are pretty simple ,gonna investigate more this evening .

[bailboy]

I had a similar problem on my k3. Mine was due to a bad brake stay bar.   Connecting the rear brake to the swing arm.  Check for any play in that as well.  When you brake does it grab and shoot the lever back up?

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[78whiteorbs]

havent rode it and will not with this problem , so I cant answer if it shoots it back up or not . Will take another good look today maybe I overlooked something simple.
When I first got the back the back brake was locked and I smacked it with a mallet and it loosened enough to be moved around. When I removed the back wheel for fresh rubber I cleaned everthing that looked crusty - slapped it back on and pedal goes very far....

[Dave Voss]

You may need to remove the rear wheel again to inspect the brake parts inside the drum.  The brake shoes pivot at one end, and expand outward at the other end when the lever arm is rotated.  It sounds like one or both of the shoes may not be positioned correctly, and it is requiring excess rotation of the lever arm shaft to cause the brake shoes to engage the drum.  It is also possible that the pivots are damaged, broken, etc.  I would agree with you about not riding it in this condition, if anything is out of position or damaged such that it could become loose, it could cause the wheel to lock up while spinning, and that could ruin your day.

[78whiteorbs]

well, I found something very obvious cant believe I didn't see this....
looks like some welding went on here... not sure why though , is there suppose to be a brake stop here on a 78?

have a look.



do I need a new right footpeg /brake stop as well?

[78whiteorbs]

I was paying so close attention to the engine I completely overlooked this . Looks like this might have been done possibly to clear the exhaust???  The exhaust is a 4-1 from what I thought was an F model. at least the header looks it .  Well at least the engine is running great now, sigh....one more thing

[strynboen]

bay a new pedal/arm..that one vill bent or breake  its soft  black iron..

[78whiteorbs]

this nut was held on with silicone...

[mono]

bay a new pedal/arm..that one vill bent or breake  its soft  black iron..

really a +1 to that -- i think it would be OK for normal use , but if you really stood on it it may bend.

other than that, I would say that even though it's abnormal, if it worked before it should work again.  I would agree that you should pull the wheel and see if everything inside is adjusted correctly.  are you using new brake shoes (I assume yes, but worth asking)?   and since it's been "customized", you may need to adjust it's position a little differently.

... I guess you could always shorten the rod that goes between the levers

[78whiteorbs]

I will be getting another one that's easy . Try to find a good pic to see if I am gonna need any other parts. Also trying to figure out why it was modified. If it was to run the 4-1 exhaust then I might have to do some tweaking. It looks like the brake are might not clear the pipes on it if it were not cut, someone else I am sure knows this....let's here it ! what exhaust is this ?

[mono]

Yeah I think it was done to clear the exhaust.  Obviously a new stock one isn't going to work for you.  I would suggest maybe just fabbing up a new one or correcting the not so good job the PO did.  You may also be able to extend the "axle" that the brake lever uses and put a spacer on it to run a stock lever.... just ideas.   

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[mono]

And is it me, or does that peg mount look long also?   Gotta say he didn't do a *bad* job... definitely some creative solutions there.

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[Nic]

If it was my bike I'd piss that ugly exhaust off, get a new pedal and new shoes. Even though the shoes still have plenty of meat on them with all that brake travel yours are kaput.

[fendersrule]

So glad I have my 4-4 exhaust.

[scottly]

Looks to me the brake arm on the rear hub needs to be rotated clockwise on the splined shaft a notch or two. Have you looked for index marks there yet?

[Nic]

Looks to me the brake arm on the rear hub needs to be rotated clockwise on the splined shaft a notch or two. Have you looked for index marks there yet?

Doesn't matter, travel is travel n that's worn out shoes.

[scottly]

Looks to me the brake arm on the rear hub needs to be rotated clockwise on the splined shaft a notch or two. Have you looked for index marks there yet?

Doesn't matter, travel is travel n that's worn out shoes.

Not necessarily. A member went through the same thing only a few weeks ago; the arm on the hub was improperly installed.

[Nic]

Looks to me the brake arm on the rear hub needs to be rotated clockwise on the splined shaft a notch or two. Have you looked for index marks there yet?

Doesn't matter, travel is travel n that's worn out shoes.

Not necessarily. A member went through the same thing only a few weeks ago; the arm on the hub was improperly installed.

If the brake arm moves more than you want it doesn't matter where it is located on the spline, it will still translate to too much travel on the pedal. The OP said he had 5" of travel regardless of the correct lining up of the dots. I didn't look at that because once he said 5 inches of travel, well say no more.

[scottly]

The OP said he had 5" of travel regardless of the correct lining up of the dots. I didn't look at that because once he said 5 inches of travel, well say no more.

The OP never checked the alignment of the hub brake arm that I read. Looking at the pics, you can see that the arm is pointed about 4:30. It should be closer to 6:00-6:30.

[Nic]

The OP said he had 5" of travel regardless of the correct lining up of the dots. I didn't look at that because once he said 5 inches of travel, well say no more.

The OP never checked the alignment of the hub brake arm that I read. Looking at the pics, you can see that the arm is pointed about 4:30. It should be closer to 6:00-6:30.

Come on mate, so if he puts the arm on at 6 o'clock the travel will be gone? Hardly. If anything, he will have more travel.

[scottly]

When the brake is applied, the arm will be approaching 3:00. The way it's now clocked won't allow enough adjustment to remove the play. I learned this lesson the hard way, on my C200 90, about 40+ years ago.

[Nic]

When the brake is applied, the arm will be approaching 3:00. The way it's now clocked won't allow enough adjustment to remove the play. I learned this lesson the hard way, on my C200 90, about 40+ years ago.

Yeah I see where you're comin from, the problem is, if you place the arm further back and then push it towards the rod you have removed the travel but the cam in the hub is now approaching full leverage and can become stuck, it's not a recommended fix, you should replace the shoes when travel is excessive. I hope this explains my point about 5" of travel n how it doesn't matter where you put the arm??? If you have that much travel you need new shoes.