| Well this may be a first for US Uraldom and this post
might be of no use to anyone for years to come, but here goes!
Sunday while the Eastern Front was having fun at the Ride
for Kids, I was at stuck at home. I had to work Saturday but Sunday afternoon I
decided to replace the rear brake shoes on Oksana.
Since I had never heard anyone post anything on replacing
brake shoes, I though I would document the procedure and post it here....for
future reference! :)
First of all, I was amazed at how much shoe material had
worn away . Even at that, the brakes were still working ok but a few rivets were
exposed and it was time to do the deed.
I removed the shoes' adjustment bolts and applied
synthetic grease to the threads and both pivot points. The new shoes were dusted
with baby powder and installed. Then, while rotating the wheel, I gradually ran
the rear adjuster in until the wheel started to drag. The wheel was then removed
and when I inspected the shoe I found it was dragging on both shoes at the end
of the friction material nearest the stationary pivot end. I used a hand sander
to bevel the edges of both ends of both shoes (see picture below).
Then reassemble and repeat the process.
Disassembly this time showed one shoe making clear contact
first and after a few turn on the adjustment bolt, reassemble.
This time everything felt right and I took a short drive
.... about 1 mile out and back. On returning the hub was HOT, so disassemble
again and inspect.
This time I noticed the new shoes were about 1/8" wider
than the old shoes and although they fit perfectly, they were now making contact
with a narrow area of the brake drum where the old shoes had not touched in
years.....there was a slight buildup of rust and road grime and the metal was
slightly higher than the area the old shoes had bedded to. The shoes had a
nicely roughed up stripe that matched the one on the drum. This required a bit
of sanding to remove the roughness on the edge of the drum since the wider shoe
would bed to this area as well.
Reassemble and.... it feels nice! One thing I noticed
right away...its much easier to mash the pedal. As the shoes wear away and we
adjust them out, the shoe return springs get extended more and more, greatly
increasing the pedal resistance. With new thicker shoes, there's very little
spring tension.
The shoes are still heating the hub a bit but its not
excessive now. I suspect that when making a shoe change on a Ural, if you adjust
them for any reasonable level of braking, there will be some heat until the
shoes wear in and bed to the drums. Remember the standard warning about not over
adjusting the rear brakes on a new Ural during break in?
Just something to keep in mind.... don't change your brake
shoes right before an important long duration ride. Give them a long slow wear
in period with gentle stops and moderate braking for a while.... I'd guess maybe
100-200km or so to do the job right, without extreme overheating.
One questionable procedure I've used to fine tune shoes
once worn in....use with caution! adjust them out until they just start to drag
then take a SHORT ride....avoid using the brakes as much as possible during this
brief ride and then pull the wheel.... the shoes will "glaze" at the point of
constant contact and light sanding on these contact points will insure a more
complete surface contact around the radius of the shoe.
Oddly enough, the front and
hack brakes look like they'll make 100,000km. :)
Ed Paynter
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