Floating rotors and replacement pins

[Raywood]

With all the talk about rotor pins I thought I would show you why replacing these pins are necessary from wear and tear. Here is a short vid to show you how worn out my rear rotor has gotten. I've replaced the pins twice already and am getting ready to replace them again with a new set of pins.

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[/ame]


I have probably over 20,000 miles on this latest set of pins and they should have been replaced long ago. I replaced last time with the wheel on the bike and it was a pain so waiting to replace my worn out rear tire and then I'll replace these.

Funny thing also is my front rotor only has about 25% of the looseness my rear rotor has and I brake with 70% of my front brake so........

I posted this based on this thread and others.
http://www.bigdogbiker.com/forums/general/18746-bunch-pins.html

But if you want to replace the rotors completely you can use about any thing you want as long as they are the right diameter which I believe is 11". Just need to ensure they are spaced properly with the caliper.

W8less is now Matrix:
www.matrixbrakes.com

RayGun Technology

Lyndall Racing Brakes - The worlds best Brake Pads & Composite Rotors --- Home ---

These companies are in addition to your PM and other traditional companies out there.

Here are a few that I've been looking at. Only thing with these it your rotor won't match your wheel.

Last thing is starting in 05 BDM started using Brembo rotors with our PM brakes. Only thing I'm unsure of is whether Brembo made both the carrier and the rotor or if BDM makes the carrier then matches up the rotor to it.

There you go :2thumbs:

 

[shovelcowboy]

Ray, when you keep replacing the pins is there no wear in the holes? It would seem that after 3 pin replacements there would be also wear in the holes so that even the new pins would not tighten things up.

Also thanks for the vid showing the slop. Do you ever hear that rattle while riding? (I suppose the centrifugal force takes care of that, huh?)

Shovelcowboy

 

[Raywood]

Good question. I didn't measure or notice it last time I changed them out but you would think there is wear on the rotor and carrier. I'm sure they thought out the design so the pins wear first but none the less you gotta think of wear on the other parts.

I think I'm going to replace them with either the new Lydall or the W8less rotors when I hit the lotto.

After I replace them this next time I will measure how much slop there is in it and update this thread.

Oh, I don't hear it cause I always have my music on but no I don't hear it.

 

[TheDeadOne]

The wear should be worse on the pins because they are made of a somewhat soft to mid-grade of aluminum. As where the rotor frames are made of steel. I'm sure that the rotor frames "do" wear, but just a bit.

Ray, the rears in your case, as with many others as well, should wear worse because you do apply your front brakes more forcefully and the rears are used more in a pulsating effect and create rattle on the pins and rotors. That's pretty normal.

dead

 

[shovelcowboy]

The wear should be worse on the pins because they are made of a somewhat soft to mid-grade of aluminum. As where the rotor frames are made of steel. I'm sure that the rotor frames "do" wear, but just a bit.

dead

Aluminum! I didn't know that. So why not harder (maybe steel) pins so they don't wear out so soon. Are they afraid that that harder pins might make the whole thing crack and 'blow apart'.

The more I learn about floating rotors, the more I wonder WHY. For years we didn't have to worry about all this stuff and the increased expense!

Here's what I put on my chopper. $99 for the pair ($14.36 shipping). Many miles, no warp, stop great, flashy chrome-look all stainless steel, look better than those on BD bikes (especially after some miles).

OEM STYLE BRAKE ROTOR PAIR PARTS FOR HARLEY : eBay Motors (item 350325358191 end time Apr-05-10 15:22:34 PDT)

Shovelcowboy

 

[Moespeeds]

Those look like DNA's shovel. That's what I put on guy's bikes when they come to me for rotors. Polished stainless looks much better than the iron we get stock, and stops better than the fancy chrome rotors.

 

[lee]

I think the reason for floating rotors is two fold. Firstly for heat dissipation so that it doesn't transfer from the rotor to the carrier and secondly to give some flex where the pads on either side of the rotor apply a different amount of pressure. I think only one half of the caliper moves when you apply the brake.

 

[shovelcowboy]

and secondly to give some flex where the pads on either side of the rotor apply a different amount of pressure. I think only one half of the caliper moves when you apply the brake.

I respecfully disagree, Lee. I just had a PM caliper apart and there are channels for brake fluid to BOTH sides AND why would they call them 4 piston calipers if only 2 on one side worked to apply pressure?

Also the holes in the ones I posted a picture of adequately act to dissipate heat.

My thoughts which just may be Wrong.

Shovelcowboy

 

[lee]

I respectfully respect your disagreement

yeah I'm not hugely sure on the one side of the caliper moving bit. I'm pretty sure the heat part is right though as to the reason for floating discs. Not saying yours don't do that well but I do think that is the reason for the two piece rotors.

 

[lee]

wikipedia

"Warping is often caused by excessive heat. When the disc's friction area is at a substantially higher temperature than the inner portion (hat) the thermal expansion of the friction area is greater than the inner portion and warping occurs. This can be minimized by using "floating" rotors which decouple the friction area from the inner portion and allow thermal expansion to occur at different rates. Primary causes of overheating include undersized or excessively machined brake discs, excessive braking (racing, descending hills/mountains), "riding" the brakes, or a "stuck" brake pad (pad contacts the disc at all times)."

 

[shovelcowboy]

wikipedia

"Warping is often caused by excessive heat. When the disc's friction area is at a substantially higher temperature than the inner portion (hat) the thermal expansion of the friction area is greater than the inner portion and warping occurs. This can be minimized by using "floating" rotors which decouple the friction area from the inner portion and allow thermal expansion to occur at different rates. Primary causes of overheating include undersized or excessively machined brake discs, excessive braking (racing, descending hills/mountains), "riding" the brakes, or a "stuck" brake pad (pad contacts the disc at all times)."

Lee, you are right on the warping in some instances. Way back in my memory bank I remember warping the rear rotor on my shovelhead. As you stated I'm sure it was excessive heat (in this case I think due to a "stuck" or poorly adjusted rear brake). It was a GMA caliper on I think a 9 inch rotor with less holes. But I think that kind of heat would not have been good for any kind of rotor. I believe that HD going to an 11 or 11.5 inch rotor with more holes was a partial fix for problems of heat. (full fix maybe being floaters)

But thanks for the great explanation above. Still I wonder if ones like I pictured and properly adjusted (and ridden right) are not a more economically feasible way to go given the cost of pins and parts for the floaters.

Thanks for your research, Lee, Shovelcowboy

 

[lee]

:2thumbs:

 

[billwr]

the floating rotors also help prevent the rotor from kicking the pads back in if the rotor gets warped the end result of thet would be mushy brakes or no brakes

 

[TCALZ06]

Hi Ray,

Do you remember at what mileage you had to replace your pins at the first time?

I have a little over 16K on mine and they have no play at all.

Also, just curious how much wear you are getting on your rotor? I'm guessing you have the most mileage of anyone on here.

Thanks
Tom

 

[Vegas]

the floating rotors also help prevent the rotor from kicking the pads back in if the rotor gets warped the end result of thet would be mushy brakes or no brakes

Bingo, they serve one purpose. Brake pad knock back. I have it wicked in the rear of my Camaro on the race track. Things naturally flex regardless of material. Wheels, hubs, rotors, bearing...etc. A floating rotor takes up that slack and give us that repetitive brake feel. These are manual brakes like I run on my race car. There is NO room for error. I applaud them for providing us with consistent brakes. The caliper is fixed on our bike and most race calipers.