primary/secondary brake shoe question

I just bought a pair of EBC shoes for a single leading shoe
drum brake. Looking at the two shoes, they're identical
except for the position of the pad material on the shoe.

One one shoe, the pad material is placed closer to the pivot
point and on the other, the pad material is closer to the end
of the shoe which is driven by the brake cam.

Which shoe should be the primary (leading) shoe ? Is it the
shoe with the brake pad placed closer to the pivot point or the
one where the pad material is closer to the cam ?

My guess is that the leading shoe should be the one with
the pad placed closest to the pivot point.

TIA

 

In 35 years of faffing with bikes, I've never worried. I've just snapped
them into place and ridden. I really don't think it matters.

Krusty will be along in a moment with more disinformation

 

The leading shoe will wear faster, so my guess is that
the trailing shoe should be the one with the pad material
placed where it makes first contact. (furthest from the
pivot point).

I gather that some drum brake designs will use differently
sized pads because of this asymmetry.

Thanks anyway

Looking forward to your customary exchange of insults with
Krusty as this thread develops.

 

Maybe. I've never, ever, ever noticed nor worried about it. I buy the
brake shoes and when they're worn, buy a new set, and clip them in.
They're SLS drums: they're not the greatest brakes around, but perfectly
adequate for some appications.

<Shrug>

The only thing I look for is a chamfer on the leading edge. In the past,
I can recall some shoes which had a chamfer on one end, but it was
invariably at the cam end anyway, and you can't put these brake shoes
in the wrong way round, so wtf.

Have you considered it could just be a slight manufacturing defect?

Insults? Moi? I just point out where he makes mistakes. It's a full-time
job, I can tell you

What bike are you putting them in, anyway?

 

R100GS. Previous pair was totally symmetric.

Differences between the shoes in the new pair lead
me to believe the vendor had something in mind
when making them asymmetric.

Seems to be a large pile of confusion and misinformation
on this subject out on there on the internet, so I figured
reeky would be a great place to solicit new and imaginative
contributions.

 

Or, as it's EBC, there's a manufacturing glitch, as I suggested.

 

This diagram is from bikebandit.com. It's a 1992 R100GS.

http://a.bikebandit.com/assets/dzimages/bmw/dzbmw001/bmw-05-05-04992_files/11/3_1.png

The parts list doesn't call out the part number(s?) of the shoes, they
are supplied as part of a *kit*.

One might interpret the diagram as showing the top shoe is slightly
different from the bottom shoe as regards the positioning of the
friction material.

 

You are formally invited to kiss my ass.

 

One would be wrong.

 

That link is useless.

 

Putting the shoes on backwards will actually reverse the Wheelie
Polarity of the bike. This results in allowing shaft bikes to wheelie
while taking the ability away from others.

 

Well, the draftsman might have been working from a photograph instead
of a lay out drawing...

OTOH, he may have been distracted by looking at pictures of the Murray
family having incest together.

You know, those pictures you used to sell on ebay?

 

You're useless without your Daddy...

 

Exactly why I want to get it right. I'd hate to
take away the ability of other bikes to wheelie.

 

Just mirror off the originals...iow DON'T REMOVE THE ORIGINAL SHOES!!!
trust me. Then you lay out the NEW shoes exactly like the old ones.
Now check your shop manuals and follow their directions. Thus your
shoes are properly pre-orientated for instalation. Well it works for
me...oh and ignore that **** up Krusty.

 

The rattle was tossed and right on cue the inbred misbredd little boy
raper shows up talking shit he can't back.

 

****...you already took the shoes out of the hub didn't you? <sigh>
why am I NOT surprised...damn bmw riders.

 

The new shoes are not exactly like the old ones.
The old ones are symmetric and the new ones are
asymmetric. It's driving me nuts. Please help.

 

The wear marks from the cam indicate the old leading and
trailing shoes, but this is useless, as the old and new shoes
differ in design.

 

The new ones have a slight manufacturing defect. Buy genuine OE stuff,
it always fits. Buy pattern stuff, it frequently doesn't, not perfectly,
not even from reputable makers.

Recently I bought a set of pattern disc pads for an old Honda. One pad
didn't fit properly because the steel backplate was fractionally too
large and was jamming in the caliper body. A couple of minutes with a
file and was perfect.

A pound to a penny this is your problem. Or, just conceivably and if the
difference is considerable, someone on the packaging line made a
mistake. In which case, buy another set.

Otherwise, fit the shoes and ride and stop behaving like DatesFat. !'ve
never come across an assymetric set of SLS brake shoes. `Doesn't mean
they don't exist, but the odds are against this being your problem.