[Louis]

I have a little disk (or Rotor, in American) warp. Everything still feels OK, but spin the front off the ground and there is a patch of the rotation where you can hear the pad rubbing and the wheel slows down.

So, how far do I let it go before I do something, and is there anything more useful and interesting I can do other than fit a new stock disk?

Oh, and would skimming me be useful?

 

[TaxmanHog]

Make sure all the mounting screws and washers are lined up allowing the rotor to float correctly.

Not sure about resurfacing, I could not find a machinist willing to do it, the cheapest solution is to swap for new.

 

[remphoto]

I just put new ones on mine after living with it for 2 years. It got progressively worse to the point it shook the bike. I was told that the replacement rotors have a different part number and are supposed to be more warp resistant. Also, there are some fancy aftermarket ones on the market which are expensive.

Someone posted having swapped the rotors side to side and that fixed the problem. Others have said they needed to replace the front wheel.

The replacement process is very easy. I was careful to torque the bolts to specs and in the correct order and now braking is very smooth as originally intended.

 

[Louis]

I just put new ones on mine after living with it for 2 years. It got progressively worse to the point it shook the bike. I was told that the replacement rotors have a different part number and are supposed to be more warp resistant. Also, there are some fancy aftermarket ones on the market which are expensive.

Someone posted having swapped the rotors side to side and that fixed the problem. Others have said they needed to replace the front wheel.

The replacement process is very easy. I was careful to torque the bolts to specs and in the correct order and now braking is very smooth as originally intended.

It hadn't occurred to me that there might be issues OTHER than changing the rotor, thanks!

 

[RustyG]

The noise could be nothing more than the pads wearing unevenly. Check them out for wear front to back.

If the rotors warp bad enough you will feel a pulsing when applying the brakes. When the pulsing gets on your nreves then replace the rotors.

The thickness of the rotors should be stamped on the rotor itself along with the part number if the early H-D branded rotors
If you have Brembo brakes the thickness minimum is .18 inches
Edited 8/3/2010 to fix thickness minimum spec.

 

[rsc]

Check the calipers to make sure the pistons are not hung up. If you have one that is out and pushing on the pad you will get this rubbing.

Check video link...cleaning the piston. suggestion only.

rod

 

[remphoto]

Check the calipers to make sure the pistons are not hung up. If you have one that is out and pushing on the pad you will get this rubbing.

Check video link...cleaning the piston. suggestion only.

rod

BTW, thanks for your video on removing/installing the front wheel. That gave me the confidence to do it myself!

 

[Louis]

Check the calipers to make sure the pistons are not hung up. If you have one that is out and pushing on the pad you will get this rubbing.

Check video link...cleaning the piston. suggestion only.

rod

Thanks. It isn't though, it is warped disk, it is quite clear.

Sounds like I can leave it until it actually annoys me, which is nice. I can't feel it through the lever yet.

 

[AOW]

Similar just happened to my rear rotor couple months ago. I found a new stock rotor on ebay for $50 shipped so had to jump on it

 

[Louis]

Similar just happened to my rear rotor couple months ago. I found a new stock rotor on ebay for $50 shipped so had to jump on it

Not much chance of that in the UK, sadly :-(

 

[Dr Dave]

Myth

Click here.

I have proved this out many times and have not replaced, nor machined rotors in 30 years (and I'm a machinist).

 

[Dr Dave]

The noise could be nothing more than the pads wearing unevenly. Check them out for wear front to back.

If the rotors warp bad enough you will feel a pulsing when applying the brakes. When the pulsing gets on your nreves then replace the rotors.

The thickness of the rotors should be stamped on the rotor itself along with the part number if the early H-D branded rotors
If you have Brembo brakes the thickness minimum is .018 inches

I'm replacing mine when they get down to 0.180" whether they need it or not.

 

[AOW]

Dave I'm very familiar with that link, I read it extensively the first time it was posted by you, (Thanks:thumb. Great article! My rear was very much warped, I believe it happend as part of a tire change and not of natural causes. With tire off ground and bike in neutral, when you spun the wheel manually you could see and hear the warp.
Once removed I placed the rotor on a flat surface and the one side was up off the table a bit.

 

[Louis]

Click here.

I have proved this out many times and have not replaced, nor machined rotors in 30 years (and I'm a machinist).

OK, fine, but even assuming he is spot on that still means a new disk (rotor) as far as I can see.

I also note I've been riding high mileages every year for thirty years but until now *I* have never seen a warped disk either. We have a disk that goes smoothly through 300 degrees and drags through 60. In normal parlance that's a warped disk, but if you want to be picky and say it isn't warped but has uneven deposits, great, whatever. And? Now what?

 

[Dr Dave]

OK, fine, but even assuming he is spot on that still means a new disk (rotor) as far as I can see.

I also note I've been riding high mileages every year for thirty years but until now *I* have never seen a warped disk either. We have a disk that goes smoothly through 300 degrees and drags through 60. In normal parlance that's a warped disk, but if you want to be picky and say it isn't warped but has uneven deposits, great, whatever. And? Now what?

You may need to "bed in" your brakes. Below is an excerpt from the "technical papers" of that same website. For the complete method click here.

"When a system has both new rotors and pads, there are two different objectives for bedding-in a performance brake system: heating up the brake rotors and pads in a prescribed manner, so as to transfer pad material evenly onto the rotors; and maturing the pad material, so that resins which are used to bind and form it are ‘cooked' out of the pad.

The first objective is achieved by performing a series of stops, so that the brake rotor and pad material are heated steadily to a temperature that promotes the transfer of pad material onto the brake rotor friction surface. There is one pitfall in this process, however, which must be avoided. The rotor and, therefore, the vehicle should not be brought to a complete stop, with the brakes still applied, as this risks the non-uniform transfer of pad material onto the friction surface.

The second objective of the bedding-in process is achieved by performing another set of stops, in order to mature the pad itself. This ensures that resins which are used to bind and form the pad material are ‘cooked' out of the pad, at the point where the pad meets the rotor's friction surface.

The bed-in process is not complete until both sets of stops have been performed."

The quotation above in bold is describes what probably happened to your rotors. What I have found is that merely cleaning your rotors with brake cleaner or wheel cleaner will remove all of the embedded pad material and instantly smooth out the pulsation. Beware, your brakes will not be nearly as effective until the pad material is reapplied through braking several times.

 

[mwdhand]

Ehhh. I've driven everything I've ever owned as though it was a rental for years. Not trying to say any of that information is wrong but I beat my truck's brakes like they owe me money and get them resurfaced whenever I wear out a set of pads (usually in the 50-60k miles range). Never had one feel warped. I usually get them surfaced because they're grooved from completely destroying the pads.

Some people just get too much enjoyment from feeling like they're coddling their vehicles. I have better things to do. Screw it let's ride.

 

[RustyG]

I'm replacing mine when they get down to 0.180" whether they need it or not.

Thanks. Post edited. .018 is a little too thin for you huh?

 

[AOW]

I've have no issue driving my car with a warped rotor or 2, but won't do it on the bike. My rear was physically bent & most places won't "turn" your cycle rotors for you. My machinist friend would do it, but he's an hour away so it was just easier to get the replacement and drop the old one off at the shop when I'm in town.

 

[Louis]

Aha! OK, I'll try cleaning the disk with brake cleaner.

I always bed in my brakes carefully... To me that's common sense.

You may need to "bed in" your brakes. Below is an excerpt from the "technical papers" of that same website. For the complete method click here.

"When a system has both new rotors and pads, there are two different objectives for bedding-in a performance brake system: heating up the brake rotors and pads in a prescribed manner, so as to transfer pad material evenly onto the rotors; and maturing the pad material, so that resins which are used to bind and form it are ‘cooked' out of the pad.

The first objective is achieved by performing a series of stops, so that the brake rotor and pad material are heated steadily to a temperature that promotes the transfer of pad material onto the brake rotor friction surface. There is one pitfall in this process, however, which must be avoided. The rotor and, therefore, the vehicle should not be brought to a complete stop, with the brakes still applied, as this risks the non-uniform transfer of pad material onto the friction surface.

The second objective of the bedding-in process is achieved by performing another set of stops, in order to mature the pad itself. This ensures that resins which are used to bind and form the pad material are ‘cooked' out of the pad, at the point where the pad meets the rotor's friction surface.

The bed-in process is not complete until both sets of stops have been performed."

The quotation above in bold is describes what probably happened to your rotors. What I have found is that merely cleaning your rotors with brake cleaner or wheel cleaner will remove all of the embedded pad material and instantly smooth out the pulsation. Beware, your brakes will not be nearly as effective until the pad material is reapplied through braking several times.

 

[Dropsomegears]

When you need new rotors

Try the EBC rotors. Not only are they true "floating rotors" but, they perfrom better then stock and are less expensive then Galfers ( and stock I'm guessing). Check them out in this thread.

http://www.1130cc.com/forums/showthread.php?t=140693

I really would like to try these so if you do let me know how they perform.