Front Brake Caliper Adjustment on 1977 R100/7

[JeramyN]

I recently changed my front brake pads and am having a difficult time adjusting my front brake caliper. Or rather, holding the adjustment I make while screwing the bottom nut/spring back on...
Here's what i'm doing...
Step 1- I adjusting caliper w/ the flat end of a chisel
Step 2- squeezing the bageezies out of the brake once set
Step 3- screwing nut w/ spring back on.

BUT when in step 3, when i start screwing, the friction from the spring on the adjusting cam turns it out of adjustment. Is there a trick or am I jut missing something? I tried having someone pull the brake lever tight while I screwed the nut back on but it still moved way out of adjustment...

Thanks in advance for your pro-tip

[Kurt in S.A.]

Hmmm...sounds like the eccentric pin fits pretty sloppily...almost like it will fall out on it's own. It's been a while since I adjusted my '78, but I don't recall having that problem. New o-rings...grease on the o-rings??

Try filing the sharp ends of the spring so that it doesn't dig into either the pin or the cap when tightening things up.

Kurt in S.A.

[Ken in Oklahoma]

I recently changed my front brake pads and am having a difficult time adjusting my front brake caliper. Or rather, holding the adjustment I make while screwing the bottom nut/spring back on...
Here's what i'm doing...
Step 1- I adjusting caliper w/ the flat end of a chisel
Step 2- squeezing the bageezies out of the brake once set
Step 3- screwing nut w/ spring back on.

BUT when in step 3, when i start screwing, the friction from the spring on the adjusting cam turns it out of adjustment. Is there a trick or am I jut missing something? I tried having someone pull the brake lever tight while I screwed the nut back on but it still moved way out of adjustment...

Thanks in advance for your pro-tip

I'm not a pro, not because I wouldn't accept money, but rather because nobody will give me any.

In your step ! I can't figure out what you're doing with that flat end of a chisel. So I can't address it. What I can do is tell you how I go about adjusting the brake pads (or doing the caliper alignment if you prefer).

When I'm done with whatever caliper maintenance I've done I will pump up the brake, squeezing and holding the brake lever. Then I will take a home made inner tube rubber band or two and wrap them around the brake lever and handlebar grip keeping the brake applied. Use as many rubber bands as you need.

Now you're holding pressure and have your hands free to align the brake pads to the disk. Now you can go down to the bottom of the fork leg, take off the dust cap over the eccentric (if you haven't done it already) and you rotate the eccentric back and forth and figure out where the eccentric "wants to be". Where it wants to be is with the brake pads flat against the disk. Put the dust cap back on and you should be good to go.

Note: I don't think you'll find this approach in any manual. The ones I've seen talk about marking the brake disk itself with a magic marker or some such thing, then apply the brake while rotating the wheel and see if the marks are removed uniformly.

My way is much better IMNSHO.

Turns out that Duane Ausherman (or his cracker jack mechanic) figured out my way before I did.

By the way, If you have a helper you can have him/her hold the brake lever while you make your adjustment.

But you should make some inner tube rubber bands anyhow. You'll find that you need them every once in a while for something.

Editing: I may not have directly addressed your concern. With the brake pads being held in place under pressure, while you're screwing the cap back on, I don't see how the brake pads could shift out of alignment.

Ken

[Kurt in S.A.]

In your step ! I can't figure out what you're doing with that flat end of a chisel. So I can't address it.

He's merely using the wide thin edge of the chisel to engage the large slot in the eccentric. I've done the very same thing.

Kurt in S.A.

[Ken in Oklahoma]

In your step ! I can't figure out what you're doing with that flat end of a chisel. So I can't address it.

He's merely using the wide thin edge of the chisel to engage the large slot in the eccentric. I've done the very same thing.

Ah! I see. I've edited my post above at the end.

Thanks.

Ken

[Duane Ausherman]

For anybody doing this job, follow Ken's method as it works far better than the manual says. Often those manuals were written by engineers, not mechanics. It shows.

[jimmyg]

don't forget another trick. remove the front axle pinch bolt and insert into the caliper adjuster. Tighten by hand and use with an allen wrench (clockwise only direction) to adjust. Then with pressure applied to the lever, back off the bolt to remove. Screwdrivers, chisels, knife blades, have never worked for me.

jimmyg