SAFETY ALERT Drum rear brake bike owners please take a look

the "friction" part, that's supposed to be BONDED to the cast shoe but instead have started to peel off. Look at the pics, especially wingnut325's his is the most obvious as the lining has completely separated. In my pic you can see them starting to peel away from both shoes at the bottom.

 

The brake shoe has a metal back where the springs attach and the posts ride, etc. This gives the shoe rigidity. Attached to that (laminated) is the wear part. This is the part that actually rubs against the inside of the brake drum. This is what people are calling the lining.

These pieces should be stuck together with no gap. I was one of the people who suffered a delamination (at low speed) and would have been disasterous at high speed (or at least turned my shorts brown...).

 

Re: SAFETY ALERT Drum rear brake bike owners please take a l

Ok here's a shot of mine:


I've also uploaded a High res shot.

If I understand you correctly the "delamination" you're talking about is where the pad is separating from the brake shoe. I think mine looks ok. Your thoughts?

 

Prock,

I don't see any obvious delamination.

Keep an eye on them. If you decide to keep them, I would check once or maybe twice a year. As far as we can tell this is an age related thing not a wear related thing and is therefor unrelated to the miles on the bike or the milage you put on them.

Replacements are not very expensive and will give you piece of mind. Having had a delam while driving, I would consider replacing a 26 year old SAFETY PART (not yelling just emphasis).

 

I came to the same conclusion. The rear shoes in my '81 have NOT started to delaminate yet, and they've still got "meat" left but they're outta there real soon as a precaution. Cheap insurance.

 

My thought is age related, and moisture related, such as a bike stored outside, or in a shed VS. a bike that's garage kept. What causes the glue to break down? Not heat. Not time alone, or they would all be coming apart at the same time.

 

TIME, you may be right. But it may be more subtle than that. Brake shoes (and pads) have anhydrous properties; they draw moisture from the air. A bike that's been used regularly all its life (like my '81) probably had the brake linings heated up often enough to boil any moisture out of the material. Whereas a bike that just sits continually pulling moisture from the air might have its "bond" break down over time. My '83 was inside kept (most of its life anyway) but it SAT for great long periods. (It had 7100 miles on it when I got it.)

I think it's simply a matter of sitting without any use. Less than dry conditions probably do exacerbate the issue.

Good call.

 

Re: SAFETY ALERT Drum rear brake bike owners please take a l

Okay, gonna give this a little bump, in part because, as Fitz says, it's IMPORTANT...but also to highlight what Polock said earlier, and Fitz has confirmed, and I have recently learned from experience. When you do replace your shoes...don't expect them to work well until you break them in.

I know in some places this advice is as controversial as "always wear a helmet," but I'm gonna repeat it anyway: BOTH BRAKES, EVERY STOP. If you're stopping with just your rear brakes most of the time...well, I won't say you're doing it wrong - but your technique could be optimized.

 

Re: SAFETY ALERT Drum rear brake bike owners please take a l

WOW!! WOW!! WOW!! What an eye opener. When I bought my xj last year, I immediately checked the wear indicator on the back drum housing. Lots of pad left according to the pointer. I will now pull the wheel off and check the shoes.

I've done my own truck brakes for many years. On the older ones with drums, you usually had to have the drums turned like they used to do to rotors before they started putting thinner ones on.

Looks like it would be very hard to turn a drum on a bike.

And while I'm at this safety check, I'll check the wheel bearing and clean and regrease it. Also it's probably not a bad time to pull the rear drive unit and grease the splines from the shaft (for those of us who have a shaft drive model).

 

Re: SAFETY ALERT Drum rear brake bike owners please take a l

Oh! and thanks for the code breakdown on the manufacturing date of a tire. Something else for me to check before riding again.

 

Re: SAFETY ALERT Drum rear brake bike owners please take a l

That was fast. Rear wheel off and pads are not delaminated, but will be replaced anyway. Lots of brake dust in housing. Cleaning time while waiting for shoes. I did have to let all the air out of the rear tire to squeeze it past the gear drive unit. Probably has a slightly wider tire than it should.

Tires are German Metzler tires and the code given above apparently isn't used by them. There are a couple of codes, but they couldn't be the week and year of manufacture.

 

Metzeler whats? Metzeler has been around a LOONNG time, those tires could be old enough to pre-date the current marking system.

The "model" of the Metzelers might help date them.

 

Re: SAFETY ALERT Drum rear brake bike owners please take a l

Fitz, I'll check the numbers. There seems to be 3 sets of numbers on them. Also my xs1100 has those ChenYang tires and the same thing.

 

mine were like that to, but i just JB welded them back on, lol, worked great!

 

Hard to turn the Rear Brake Drum???

They Engineered two safeguards so you won't go Metal to Metal.

A Pointer showing the degree of wear.
(Grab your wifes Red Nail Polish and add some color to the Pointer.

The Rear Brake Adjustment Rod does NOT have sufficient threading to allow the Adjustment Nut to be place at a point where the Pad will wear beyond a Minimun Thickness.

 

Until one comes off and locks your rear wheel at speed... I certainly wouldn't trust my life to JBWeld to save $30.

 

Ohhhh, Fitz, its just a safety issue. Why would he care about a safety issue? After all, LOL takes care of that, right?

Yukon, new pads are not very expensive. If you can't afford new pads, you can't afford to ride a bike. IMHO

 

We just brought home an 81 XJ 750 and a 81 XS 400. Both have been sitting for a good while out side. Nice machines and my friend made a really good deal for the pair of them. You can bet the rear shoes will be one of the first things we pull and inspect. After my experience with the 650 earlier this year there will be parts on order real soon. By the way anyone out here have a good front fender for an XS 400 they want to sell?

 

I think its time for me to check out that squeak in my rear brake...

 

I'm gonna check mine right now, thx bigfitz. shiny side up bros and sisters!



1982 XJ650-current daily ride
1994 XJ600 Seca II-current alternate
1984 V45 Magna (x2)
1981 XS650 Heritage Special
1979 GS425 Suzuki (x3)
1948 Harley-Davidson Panhead
1967 Triumph Daytona factory chopper
1953 Triumph 500 Speed twin
1981/82/83 XV750 Virago- this was my favorite bike. I would trade both my XJ's for a nice XV750. It had the crankcase from an '83, front cyl was '82, rear was '81 and the front end was from an '82 XJ400.