Front disc brake pads slightly scratching rotor when moving bike around. Is that ok?

[Wanderer]

As you guys know I'm an old guy and I'm used to drum brake pads being adjusted to barely scrap the drum when they are adjusted right.

My front disc brake pads on my bike are slightly rubbing when I push the bike around to move it or to put it in the shed. Is that right?

It doesn't bind and I don't feel any drag when I'm pushing it around. After a longer ride, I checked and the front disc brake isn't hot or smell hot in any way.

Is there an adjustment for this? I didn't think that disc brakes were supposed to rub at all.

[allanoue]

normal

[Wanderer]

Originally Posted by allanoue

normal

Great. Thank you.

[Brother Michigan]

Just for future reference, disc brakes lack any sort of adjuster like you would find on a drum brake. Since there's no return mechanism for the pad, it will always be riding just on top of the brake rotor, making them self-adjusting. That's the light scratching you're hearing and just one more reason I like disc brakes SO MUCH more than drums

[Wanderer]

Originally Posted by Brother Michigan

Just for future reference, disc brakes lack any sort of adjuster like you would find on a drum brake. Since there's no return mechanism for the pad, it will always be riding just on top of the brake rotor, making them self-adjusting. That's the light scratching you're hearing and just one more reason I like disc brakes SO MUCH more than drums

I see. But my back one doesn't seem to be scratching or rubbing, so I wasn't sure.

Thanks.

[Triple Jim]

It varies a little. If it's dragging so much that you can feel resistance when you push the bike around the garage, it may be dragging too much. The caliper piston seals are springy, and tend to retract the pistons slightly when you let off the brake. If the rear is doing that a little better than the front, that may account for the difference you're feeling.

[Wanderer]

Originally Posted by Triple Jim

It varies a little. If it's dragging so much that you can feel resistance when you push the bike around the garage, it may be dragging too much. The caliper piston seals are springy, and tend to retract the pistons slightly when you let off the brake. If the rear is doing that a little better than the front, that may account for the difference you're feeling.

No Jim, no resistance felt at all. I even lifted the bike off of it's front wheel and spun the front wheel by hand, no binding or resistance felt. The only thing that made me question the front disc scratching was that the rear was not doing it also.

So, I guess it is ok then.

Thanks

[allanoue]

next time you change the pads, be sure to lube the pistons.

[Wanderer]

Originally Posted by allanoue

next time you change the pads, be sure to lube the pistons.

What with Al?

[allanoue]

Originally Posted by Wanderer

What with Al?

I think @Ghostt can answer your questions more fully but just any old lube will do ya.

[Wanderer]

Originally Posted by allanoue

I think @Ghostt can answer your questions more fully but just any old lube will do ya.

Ok, who ever sees this, WD40? Motor oil?

[allanoue]

Originally Posted by Wanderer

Ok, who ever sees this, WD40? Motor oil?

https://www.google.com/webhp?sourcei...+lube&tbm=shop

[Wanderer]

Originally Posted by allanoue

https://www.google.com/webhp?sourcei...+lube&tbm=shop

Excellent. Thank you.

[Ghostt]

Someone say lube?



But seriously, here's my write-up on caliper maintenance.

I recommend that every time you change your pads, you service the calipers, he's my write-up to help you out. It should fix your initial problem, and keep your calipers in top working order.

For those of you whom are scratching their heads, here you go,*

Front Caliper Service (also rear as well)

Many folks have posted here with a Varity of front brake problems.

*Many of which are attributable to the lack of proper maintenance.

*Here’s how you can always have a brake like when your bike was new.

A short list of the problems and the causes.

Soft lever or lever goes to the bar.

The usual cause is the pistons are pushed too far back into the caliper by a flexing a warped, coned, disc.

*Using up too much piston travel before the disc is pinched.

Juddering in sync with wheel rotation.

The disc is worn, and its thickness varies. *This causes the caliper to “sink” into the thin part and when the thick part comes around, it gets wedged into a smaller space causing a tightening of the brake. Then the tight spot passes through and it like the brake is released. Then repeat, repeat.

Cupped, coned, or warped disc.

Unfortunately this is a common problem with EX’s the cause is the disc is stretched in the center due to being rigidly bolted to the wheel. *The huge force of braking is transmitted to the wheel through the webbed center of the disc which gets stretched and becomes larger than the space it occupies in the center of the disc. This causes the center to push to the side trying to find room for itself.

*Resulting is a cone shaped disc.

Soft lever 2

The caliper has pistons only on one side, so as the pads wear the caliper must shift sideways apply even pressure on both sides of the disc.

*To allow this the caliper floats on two pins. *If these pins get dry (no grease) dirty or bent. The caliper won’t center itself and bends the disc to wherever it is.

This take up lever travel and when released pushes the pistons further back than necessary.

*If not fixed will eventually destroy the disc (warp it).

Ok how to prevent all of the above.

When new pad time comes around, resist the temptation to just pop in new one and go.

*Every time you must do these things.

Remove caliper disassemble and clean it.

Clean and re grease the sliding pins.

Polish the caliper pistons to remove dirt. If you just push the pistons back into the caliper leaks will result. Or binding.

Tools required:
12 mm socket
8mm open end wrench
3” or bigger C clamp
a supply of new bake fluid.
wire brush and or steel wool.

Remove the caliper from the fork leg but leave the brake line on.

Remove the old pads and the mounting frame (the sliding pins)

Remove the cover from the Master Cylinder on the Handel bar.

Attach the C clamp to one of the pistons but don’t squeeze it. *Pump the lever on the bar slowly to push out the other piston almost all the way. *Put the C clamp on that piston and push out the other one.

Remove both pistons by hand.

Remove all the rubber part from the caliper, the seals are in the grooves in the caliper and dull pointed thingy will get them out easy.

Disconnect the caliper from the brake line.

Soak all the rubber parts in new clean brake fluid * ONLY!!!!! * Rub them with you fingers till as clean as new.

The caliper can be cleaned with a wire brush or even a Moto tool for the internal grooves, NOW’s the time to paint it if you wish.

Polish the pistons till they are smooth and shinny. They are chrome plated. If any of the plating is chipped or damaged below the dust cap groove. *Replace it.

The master cylinder is the subject of another write up and we’ll assume it in good working order here.

If you suspect your disc is bad, your bets bet is to replace it with an after market one fro EBC or Galpher.

*Don’t remove the disc unless you intend to replace it. *It will assume a new shape if it is * stressed and will not be flat again. You can try to check its condition by placing a straight edge across the face of the pad swept area looking for any distortion.

Re assembly

Take the nice clean rubber seals and install them into the caliper then the Dust covers.
Wet all the rubber with new clean brake fluid and partially fill the caliper with new fluid.

Push the pistons though the dust seals and into the caliper body until the dust covers snap into the grooves.

Fill the MC with new fluid and pump the lever while holding the Line above the MC till clean fluid flows.

Connect the line to the caliper while holding it above the MC.

Pump the lever with the bleeder valve open till fluid flow from the bleeder.

*Hold the caliper so that the bleeder is the highest point.

Close the bleeder and pump more fluid into the caliper but don’t push the pistons all the way out.

Then squeeze the pistons all the way back in and install the new pads.

Re grease the slider pins and assemble the dust seals and re mount the caliper on the forks but leave the bolts loose.

Now clamp the caliper to the disc with the brake lever.

Look at the space between the fork lugs and the caliper, clamp and release a few times as you tighten the bolts by hand. It one lug touches much before the other the odds are you mounting bracket is bent. You can straighten it.

*After you get it the best you can. Some shim washers made from alum can stock can be fitted to the loose side.*

** *What we are doing here is trying to minimize the bedd in time and gets the best pad life.


Ok with everything tight you should be through, Notice we don’t need to bleed the brakes, but if you screwed up in any of the above steps, you might do that here.

Be careful to Bedd in the new pads gently.

*Too much pressure too soon will burn the pad material as only a small area will be gripping at first. You also won’t have full braking power till the pads are fully familiar with the disc

I also recommend flush and fill with new brake fluid, also I'd go with 5.1DOT.

No matter what kind of brake fluid you choose, always periodically flush and fill with new fluid.

This is the one I use


https://m.motul.com/ca/en-us/product...-1-brake-fluid



Also inspect the brake lines, replace is needed, http://faq.ninja250.org/wiki/Stainle..._lines_upgrade

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As you can see, we're sort of obsessed with quality and safety. We look at it this way: If we're asking you to put our brake lines on your bike, you're trusting us with the integrity of your brakes. That's a serious concept and we refuse to compromise when it comes to the integrity of your brakes.

I have these stainless steel lines on my Ninjette, and so far, some good, I recommend getting the stainless steel banjo bolts, I noticed my chrome ones have started to rust slightly, a good excuse for me to upgrade to titanium

On my 91 EX500 I have Spiegler, in orange to match that bike.

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At Spiegler, our brake lines are made of only the finest materials available.

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When it comes to safety items like brakes, when in doubt, throw them out, it's your safety in your hands, and is cheaper than a visit to the ER.

Buy quality pads,I personally recommend EBC brand either the HH, or the Extreme HH.

EBC full floating rotor, replace the OEM rubber line with a stainless steel braided brake line, cheaper than replacing them with OEM.

On my 500 I have Spiegler line

http://www.spieglerusa.com/brakes/cy...line-kits.html

On my Ninja 250 i went with Venhill

http://www.venhillusa.com/products.html

With all that, it will stop on a dime, and leave you nine cents in change.

look here http://ebcbrakes.com/products/motorcycle/

And also read this, http://www.ex-500.com/wiki/index.php...otors_and_Pads

That should answer any questions you might have.

[Wanderer]

Originally Posted by Ghostt

Someone say lube?

That should answer any questions you might have.

Wow! That is great info! Thank you!

You guys are GREAT!

[Brother Michigan]

Originally Posted by Triple Jim

The caliper piston seals are springy, and tend to retract the pistons slightly when you let off the brake.

Ah, yeah, I forgot about those square-cut seals...

[Ghostt]

For slider grease I use this,

Permatex 85188 Ultra Disc Brake Caliper Lube, 0.5 oz.



https://www.permatex.com/products/lu...aliper-lube-4/

Permatex® Ultra Disc Brake Caliper Lube

Category: Specialty Lubricants - Brakes
An environmentally-friendly, green, no melting, synthetic lubricant. It is formulated to lubricate under the most adverse brake conditions, assuring that critical caliper pins, sleeves, bushings and pistons remain lubricated throughout pad life.

Motorcycle
Suggested Applications: Guide pins, disc brake pad

Permatex 85188 Ultra Disc Brake Caliper Lube, 0.5 oz. https://www.amazon.com/dp/B004WJPN2A..._8EX9xbFYH2VWN


Remember, Just a dab will do ya'

I can not stress the importance of brake maintenance, under hard/panic braking, the front brake does almost all the stopping, and the Ninjette only has a single disc/caliper.

So the next time you do your pads, just remember that, and proper maintenance of the caliper only takes a few extra minutes, and it's easley done.

When you consider the alternative, of causing yourself harm, aren't you worth the extra time?

In the end it's your call.

[Triple Jim]

Originally Posted by Ghostt

...under hard/panic braking, the front brake does almost all the stopping...

That's for sure. The fastest stop I can do on mine raises the rear wheel off the ground.

[Ghostt]

So true.

Caliper maintenance is one of the most overlooked items, along with valve adjustment.

The difference is caliper maintenance is a whole easier to do.

[allanoue]

Originally Posted by Ghostt

So true.

Caliper maintenance is one of the most overlooked items, along with valve adjustment.

The difference is caliper maintenance is a whole easier to do.

One is more of a safety issue as opposed to a performance issue.

[Ghostt]

Agreed, but on the list of overlooked maintenance items I would put these two in the top 5.

With calipers being #1 because of that reason of major safety/major injury issue.

Due to the Ninjette is an "entry level bike" and they change hands often, with little to none of any maintenance done.

With SERENITY being a prime example of this, 27k when I got it, and the only thing done was a few oil changes, and set of tires.

Most people buy these to learn on, and then sell them for bigger and better things, they aren't interested in maintenance, if any is done it's most likely the minimum amount.

Regardless of why you purchased the Ninjette, you need to make it safe and reliable for yourself.

[Wanderer]

Originally Posted by Ghostt

So true.

Caliper maintenance is one of the most overlooked items, along with valve adjustment.

The difference is caliper maintenance is a whole easier to do.

I agree with this. And I have to spend time before my long trip next year studying up and doing this on my bike. It is about time for new brake pads anyway.