Recent and unusual response from Rear Drum Brake

[EvenmoreXS]

Hello there fellow forum members. I am seeking advice on a starting point for an unusual problem I've recently begun to have that is somehow involved with the rear brake. I'll do my best to explain in long story short form:

Bike sat during the cold weather under my carport. I did start her every couple of weeks just to let her run for a moment.... Insert jokes about Florida's " Cold Weather " here ____________.

Upon riding again I've been noticing an intermittent issue that's bugging me.
It only does it about every 20th time I use the rear brake. Braking conditions ...hard or soft seems to have no effect on if it does it or not.

When riding and coming to a stop Im a front and rear brake guy.. I use both gently.. or as needed obviously. I've been using the rear brake a little more lately just in trying to find some form of reference... Like it only does it in second gear, or it always does it when I only use the rear brake but I cant find any degree of consistency or predictability other than a slight difference in feel in the brake pedal depression that tells me it may do it " this time "... and it is a very minor feel, but I can feel it.. Or maybe Im being hyper observant and noticing something that isn't there.

But here it is... Occasionally, and mostly unpredictably, when using the rear brake there is a... for lack of a better word... a POP,, or a CLANK. Last one split second and braking is normal. I can feel the clank in the pedal but also what feels like the entire bike. It isn't violent but it is worrysome. To compare the way it feels to something unrelated.. consider the way it feels when you drop into first gear from a stop and the gears engage. It doesn't lunge or pull forward but you can feel it engage. "Clank".

My idea is it has something to do with the drum stay arm... or the pivot in the drum, or one pad wearing different than the other.... My concern is that it has something to do with the fact that the chain is involved due to being connected to the sprockets which in turn in connected to the tranny.... Im probably overthinking that last part.

I have to do some more riding and checking but it did it in fourth, third, and second gear and Im pretty sure it did it In Neutral while pulling into my parking garage earlier today.. could have been 2nd but I was in the process of downshifting and I cant be positive if I had completed the change.. Again, I have to try to see if I can get it to do it while rolling in neutral which may rule something in or out.

Braking seems to be fine other than this but it does concern me. Want to jump on it soon..

Please chime in with any experience or advice.


For reference, I was going to change my brake shoes about 2 years ago but there was so much good material there at the time I left it alone. Had no problems since then until this in the last few weeks. I've probably put 8k miles on it since then. Maybe less but I doubt more.



As always, Thank you to you all. You are an invaluable resource of knowledge and inspiration..

 

[cycleranger]

It's possible the brake liner has come loose from one of the shoes.
Take it apart and check everything, don't shirk with brakes, an issue could cause a wheel lockup!

Once you eliminate brakes you can investigate further if the issue persists.

 

[gggGary]

Yup stop riding take apart I might be checking a loose axle or torque brace also.

 

[EvenmoreXS]

It's possible the brake liner has come loose from one of the shoes.
Take it apart and check everything, don't shirk with brakes, an issue could cause a wheel lockup!

Once you eliminate brakes you can investigate further if the issue persists.

Hadn't thought about a free'd brake shoe liner. That would be pretty rare but would be easy to spot once im in there.

 

[gggGary]

Not rare I have seen at least 10 shoes separated on old Yammies I own. Mostly rescue bikes. Sitting out in the in rain or damp areas for long periods hastens the process.

 

[EvenmoreXS]

Yup stop riding take apart I might be checking a loose axle or torque brace also.

Yeah, my ride home tonight will be my last until I figure it out. I have been trying to find anything loose or sticking/hanging in the torque brace and the brake adjustment but everything appears to be tight and tidy.

Thanks for the quick replies. I'll keep you informed of what I find.

 

[EvenmoreXS]

Not rare I have seen at least 10 shoes separated on old Yammies I own. Mostly rescue bikes. Sitting out in the in rain or damp areas for long periods hastens the process.

I will very likely get in there tonight or at least sometime this weekend.

I'll supply pics or a video of what I find.

 

[cycleranger]

Not rare I have seen at least 10 shoes separated on old Yammies I own. Mostly rescue bikes. Sitting out in the in rain or damp areas for long periods hastens the process.

When rebuilding my CJ360T I found that the PO had epoxied the liner back on to a shoe in the front hub!
Hey plenty of liner left, right?

 

[EvenmoreXS]

When rebuilding my CJ360T I found that the PO had epoxied the liner back on to a shoe in the front hub!
Hey plenty of liner left, right?

WTF. Brake shoes aren't that damn expensive. Shit. Luckily Ive been inside mine and they had plenty of material left. I was planning to replace them but they had plenty of life left. That could be different now.

What do you guys recommend for replacement pads if needed. Just the typical Vesrah shoes...? Mikes isn't my favorite but they are a 1 day ship for me.. or amazon prime.

Recommendations appreciated.

 

[TwoManyXS1Bs]

...I might be checking a loose axle ...

Here's an unusual circumstance involving axle adjusters:

http://www.xs650.com/forum/showthread.php?t=34841

 

[EvenmoreXS]

Here's an unusual circumstance involving axle adjusters:

http://www.xs650.com/forum/showthread.php?t=34841

That was a very good read. Thanks for sharing. I'll look at that stuff this weekend when Im in there. I know I have a gremlin somewhere and I gotta find it. She is a daily rider most of the year. Needs to be as safe as It can be. Planning to get a new back tire next week so nows the time.


On a side note, on my way home yesterday I got to use my full emergency braking and it worked fine.. no "clank" or funny business.. worked great. A ginormous douche bag fuck wad ignoramous r-tard king of the fucking idiots cager left a business on the opposite side of traffic, drove across a turning lane, 2 lanes of traffic, another turning lane, the median, out in front of me, then across two more lanes of traffic and into the turning lane on my side of traffic.... so literally straight across 7-8 lanes of afternoon traffic... 90 degrees from the flow in both directions. I had to slam on the breaks to not hit him in the side. I was in total control though. She didn't act funny at all. The Ass hole had to audacity to point at me out his window as if saying "my bad". I shook my head at him as if saying "go fuck yourself you fucking fuck face fucking fucker. And then die."

I hope he heard me.



I have diagramed the event in a MS Paint drawing. The bleeding dick hole scum bucket is represented in red.. My travel is represented in green, and the near miss location is represented by the yellow circle. Enjoy. And please by hyper aware, defensive, and ride safe.




# Stupid people piss me off.

 

[Brassneck]

One thought I had, regarding your "clank" sound could be the adjustment nut and/or the threaded brake arm connecting rod.

I had a bike back in the day when I first started riding that made a "clank" sound when I applied the brake...noticeable to me, similar to what you described. I dug in, and searched for obvious issues...and tore apart the rear brake without ever seeing anything. I finally found that the adjustment nut was the culprit.

The nut was as tight and as high as it would go on the rod in order to provide a solid brake...(Note: the brake arm needed to be adjusted better, but I was too new and ignorant to know enough about that at the time). It was just beyond the final threads on the rod (That I couldn't see because of how the barrel nut/thing was sitting over the threads)...in my scenario, the adjustment nut would sit tight in there, and the back pressure from the brake arm had it feel solid, so that any manual push/pull by hand I couldn't see or hear any issues, but with enough of a quick brake by the lever with foot pressure, it would POP back a thread...creating a "Clank". When I would release the brake lever, the tension from the brake arm would push it forward again....and this would repeat over and over and drove me nuts until I figured it out. Re-adjusted the brake arm, and problem went away.

Not sure if this is what you're facing...bur might be something to look into.

Good luck

 

[EvenmoreXS]

One thought I had, regarding your "clank" sound could be the adjustment nut and/or the threaded brake arm connecting rod.

I had a bike back in the day when I first started riding that made a "clank" sound when I applied the brake...noticeable to me, similar to what you described. I dug in, and searched for obvious issues...and tore apart the rear brake without ever seeing anything. I finally found that the adjustment nut was the culprit.

The nut was as tight and as high as it would go on the rod in order to provide a solid brake...(Note: the brake arm needed to be adjusted better, but I was too new and ignorant to know enough about that at the time). It was just beyond the final threads on the rod (That I couldn't see because of how the barrel nut/thing was sitting over the threads)...in my scenario, the adjustment nut would sit tight in there, and the back pressure from the brake arm had it feel solid, so that any manual push/pull by hand I couldn't see or hear any issues, but with enough of a quick brake by the lever with foot pressure, it would POP back a thread...creating a "Clank". When I would release the brake lever, the tension from the brake arm would push it forward again....and this would repeat over and over and drove me nuts until I figured it out. Re-adjusted the brake arm, and problem went away.

Not sure if this is what you're facing...bur might be something to look into.

Good luck

Thanks Brass,

I've looked at that adjustment a dozen times or more and cant find anything out of the ordinary. I've adjusted it and fiddled with it and made sure things are snug and not slipping. Not that it isn't the problem, just that it isn't the smoking gun yet. That was my original idea though. I thought it was hanging and when I push the brake pedal it would hang and then release resulting in the Clank as it snap engages instead of steady pressure applied gradually. My clank only seems to occur when pressing, not releasing.. Not that releasing doesn't cause the problem and the clank is the result. I wonder about the freed shoe surface inside... when pressing everything goes against the drum, then when releasing brake pressure things may move a bit.. then when reapplying the brake things "Clank" back in to position and braking pressure is then normal. Obviously just a theory... but inside the realm of possibility with all the moving parts.

I don't think my axle or bearings is causing it.. Been riding it for years like it is.. then one day after sitting for the winter.. there it is. A bit random, but that's how unpredictable things are. I know I will be able to figure it out, but I bet it wont be the first thing I look for... it never is.

Thanks for the reply.

 

[EvenmoreXS]

Aight, So.....

I took my back wheel off and took things apart, cleaned them a bit, sanded the drum and brake shoe surfaces, lubed things up and reassembled them. I didn't find anything that stood out as being suspect. After putting things back together I went for a short ride.. 10-15 minutes or so but I couldn't get it to do it after reassembly... Maybe a good thing, maybe not. Obviously Im going to keep a close eye on it. I've attached a few pics. Im getting a new back tire later this week so things will be apart again. Per the previous thread that was mentioned I attached a photo of the axle nut.. Keep in mind I have a axle mount tag bracket so without that Id be showing 1.5 threads it appears. Seems normal per the earlier mentioned thread. Bearings rolled smooth and didn't feel weird at all. Couldn't find any play in the swingarm or brake stay arm. Everything seemed to adjust properly. I had a slight tight spot in chain rotation with the master link on the top of the rear sprocket. Everywhere else it was even. I couldn't quite get it perfect but that could be because Im paying too much attention. It was noticeable but didn't seem too bad. I measured to the center of the axle and was matching on both sides. Of course id like to get it perfect but I may do that again or wait until I get some new parts in. Gonna be putting new front brake pads on this week. In the near future I plan to replace the rear brake shoes, both sprockets, front sprocket seal, and a new chain. Maybe a new headlight and a sprocket hugging tag bracket. Gotta relocate some wiring for that, so back burner.

Please chime in with any comments, helpful tips, jive turkey talk, ...or beer coupons.

Also, recommendations on quality rear brake shoes would be appreciated.

Thanks again to everyone ! Be safe.

 

[fredintoon]

Hi Evenmore,
that axle nut photo gave me a WTF? moment until I recognized the tag bracket for what it was.
The next time you put a cotter pin through there, please do it right.
The cotter pin should be inserted through the hole at 90º to the way it's shown in the photo with it's eye snugged down into the castle nut's slot, it's shorter leg bent out and over the end of the bolt and it's longer leg clipped to be short enough to be bent back flat against the castle nut's face.

 

[gggGary]

Lighten up fred
A: it's GOT a cotter pin
B: its not a nail or piece of bailing wire!

both methods are "acceptable"


Full disclosure I usually use a "hairpin" clip.

The easier I make it to do maintenance the more likely I am to do it.

 

[EvenmoreXS]

Hi Evenmore,
that axle nut photo gave me a WTF? moment until I recognized the tag bracket for what it was.
The next time you put a cotter pin through there, please do it right.
The cotter pin should be inserted through the hole at 90º to the way it's shown in the photo with it's eye snugged down into the castle nut's slot, it's shorter leg bent out and over the end of the bolt and it's longer leg clipped to be short enough to be bent back flat against the castle nut's face.

Thanks for being observant Fredintoon. That pic was mainly to show that Im not bottoming out the nut and getting a "False" reading on the axle nut related to that previous thread that was mentioned. When Im ready to ride again I'll have it right.

 

[EvenmoreXS]

Lighten up fred
A: it's GOT a cotter pin
B: its not a nail or piece of bailing wire!

both methods are "acceptable"


Full disclosure I usually use a "hairpin" clip.

The easier I make it to do maintenance the more likely I am to do it.

Good thing I replaced that bobby pin with the cotter pin right before I took the photo. Fred would have really got me on me then..

But your right about the bailing twine. It never held right. Probably because it was orange.

 

[5twins]

You may have just been at the point where the drum needed to be cleaned and lubed again. they can do some strange things when the lube goes away. On one of my other bikes, the rear drum started howling and screeching last summer. It had been squawking a little the first time I applied it on every ride, but that went away after a couple applications so I just attributed it to a little rust forming on the drum surface. Well, last summer it stopped going away, lol. Time for a look-see. The drum was clean as a whistle inside, no rust at all. OK, might as well re-lube it I thought. Jeeze, I know I did this when I got the bike. Wait, that was like 22 years ago, lol. That was the problem, the grease was all dried out. A cleaning and fresh grease, and now it's quiet as a church mouse.

But now I know about the best grease to use, that Sta-Lube premium red stuff, as recommended by 3M from Vintage Brake. Back when I originally did this drum, I was using black moly stuff.

 

[fredintoon]

Hi 5twins,
a quote from the Velocette Owner's Handbook.
"On fitting new brake linings, smear a little grease, about as much as will fit on a finger nail, around the drum's braking surface."
Mind you, back when the book was printed the modern hi-tech brake lining material was woven asbestos.