Drum Brake Questions...

You wouldn't be the first guy to do it.

Keep the shoes scuffed up with some real rough sandpaper, glazing is bad.
I cut in grooves at a 45 degree angle on shoes with a square edge file also,
maybe 3/4 of an inch apart. Gives dust, water a place to go.

But yeah, the yz drums good.

The YZ's used the same hub style for years. They might even interchange from 74 up through the early 80's. The backing plate uses the single actuating arm with the exception of the YZ465 which uses the dual actuated setup. The notch for the backing plate stay where the fork leg hooks in will be different though from the early straight leg forks to the offset axle forks. The early straight leg YZ's and monoshock MX250 and 400's wheels might be direct replacements for your bike and a complete front end from one of those would get you alloy triples and those lightweight lower fork legs.

My dad had a 75 MX250 and to increase the front brake performance we went with a brake cam out of a YZ250 (I think it was the same year). The YZ's cam was slightly offset, while the MX's was centered.

The brakes still sucked, but they were a little bit better.

80 to 84 YZ's had the "double leading shoe" brakes, that would be an upgrade if the hub would fit.

Also, not all brakes shoes work the same, EBC and others work better than the cheaper ones.

The backing plate groove that the fork lug fits into is further back starting in 82 I believe. Almost 90 degrees. Keep that in mind as the brake cable would have a big loop sticking out front of the bike if you tried to use it on straight leg forks.

This will work for most drum brakes!


Maico Conical Front Brake – Making It Work
The Maico conical front brake has been known for better or for worse for many years.
For the most part it has been considered a marginal brake with modest braking ability.
This characterization is rather undeserved as the brake can be made to work with the best
of the drum brakes of the ‘70’s and early ‘80’s. So how do you make them work? Here’s
how…
First you must decide which side (right or left) you want to run your front brake on.
Most of the ‘70’s Maico’s were set up to run on the right side. The switch to the left side
occurred in about 1980. Why? – As suspension travel continued to increase the amount
of cable movement grew to almost a foot when the forks were compressed. This
presented the potential for some dangerous cable routing problems if run on the right
side. Personally, I have had a few years experience with CZ which also had a similar
right side set up going into the early ‘70’s but most changed over to left side operation for
the same reason – the cable routing was less obstructed and flowed easily across the
number plate and down the left fork leg to the brake arm. Quite a few Maico riders
figured this out in the ‘70’s also and set their bikes up accordingly.
To make the switch to the left side you need the following:
1. A longer brake cable (same cable length as the early ‘80’s Maico).
2. An early ‘80’s front brake stay. This is required so that the cable plugs into the
holder hole correctly and the stay is machined to fit the backing plate correctly.
3. A longer brake lever arm is used to provide increased mechanical advantage. An
early ‘80’s Maico piece works great or anything else that will fit up properly.
4. Don’t forget the brake cable holder and pin. Again, early ‘80’s Maico stuff.
Now to the meat of the matter…
It seems that most of the aftermarket brake shoes available today need to be worked over
to be made suitable for first class stopping. The EBC shoe in particular needs some
work, the FORMA to a lesser extent. The nature of the work is truing the brake shoe to
the lining. “Arcing” is the correct term. There are shops that have equipment to do this
and it may involve not only truing the brake shoes but also the brake lining in the hub.
Most often, I find the hubs to be acceptable and most of the results come from truing the
shoes. To do this you need a simple lathe and some simple fixturing. The object is to
take your backing plate with the shoes mounted up and spin them so the shoes can be cut
round. An 1/8” wide parting tool works great.

A simple fixture can be made from a ½” bolt with the hex head cut off so it will fit in the
chuck. If you want to get fancy you can make a spacer to fit the hub hole and make the
fixture self centering. Otherwise, center the piece and away you go. Take off just
enough so the brakes are round. It has been my experience that the sides may vary up to
nearly a 1/16th inch or more difference from start to finish.
I have found some brake linings to be pretty thick too, thick enough so as to not leave
much room for adjustment when you get them in the hub. To address this problem I have
milled the brake cam faces down as well as turning down the linings to free up space for
operation.
Apply some grease to the cam and shaft and reassemble. Occasionally, you will find that
the spacer on the small side of the hub will need shimming so as not to bind the fork
action. If you have access to a lathe you can make yourself a spacer of the required
length. I like a stronger spring especially near the cam and find a CZ brake spring to do
the job nicely. The Maico brake springs seem a little wimpy to me and do not yield a
good crisp brake action. Adding a rear brake rod spring to the exposed cable also helps
make the action crisp.
If you want to keep your brake on the right side go right ahead. Yo u don’t lose much if
you do the tweaks that apply. It will still work much better than if you had not done
them.
With these tweaks accomplished, you will have a brake that now feels like a Yamaha YZ
drum brake, widely recognized as one of the best brakes of the era. Enjoy it! Sweet!
Todd McGregor, Northwest Maico and CZ