So I'm curious... when a rotor gets milled and metal is removed from the high spots, those spots end up thinner, right? The outer surface of the rotor will be flat, but overall thickness is no longer uniform. Doesn't that make the rotor less able to handle heat consistently? It seems like a "turned" rotor with thinner spots would be much more likely to warp again or even crack from uneven heating and cooling stress.

 

I have seen some crack from absolute abuse, I have seen some solid ones sheer off the hub, and I have seen some vented ones scored down to where there is disc on one side, and just stubs of fins on the other (yes, these are from cars on the road with us!!!)

I brought this up once before when someone was arguing that the AC compressor on the Fit was electrically driven and even disputed this when I told him I could see the compressor (he claimed I could not).....Honestly, cannot the moderators provide some sort of testing of mechanical aptitude prior to allowing folks to post? Claymore, I see you are a moderator, have you all considered this? Granted, I am from the dyed in the wool "car owners cub" days, paid dues and paper newsletters with required car ownership and ways of removing fiction from fact.

I guess this is a downside of the net, anyone can be an expert now with no backing, busted knuckles and thousands of under hood hours and dollars in tools? Dunno

 

I have been around for a long while and and have worked on mundane US cars to cars from companies that no longer exist and (in some cases) the country of origin no longer exists....but I still do not know everything, nor pretend to.

Part of the his post is right, you can imbed some material from pads (especially modern metallic pads) in rotors. But, back in the good "organic pad" and asbestos days, this did not happen, and there were a lot of bent/warped/distoted drums and rotors in those days too.

I was a bit hot about this yesterday, but I wish these guys would say something like "check this out, it claims rotors cannot be warped" and we could have a discussion and learn from one another, not making a blanket statement that rotors do not warp with no other backing than an article on the net.

Part of this is probably why I do not work on cars anymore for a living.......

 

It's funny... I wrote my initial post in this thread in a bit of a hurry, and I actually wondered later if the discussion might have gone better if I had started it with something other than simply "rotors don't warp."

Over the years, I've seen very similar debates about rotors on other online forums (and between actual people in person), and the eventual conclusions were that the rotors weren't warping. These prior discussions were my primary reason for being confident about what I was saying... the article helped, but I'm generally not someone who immediately believes something like that on face value.

Believe it or not, I'm one of those "black gunk under my fingernails" guys too. I've never worked on cars for a living... it's a hobby for me, but I've modified a variety of cars over the years, and I've done it all in my own garage and learned from my experiences. Everything from rebuilding a DOHC 1st gen Integra head in my bathtub to installing Koni inserts in struts with a Sawzall to making custom ECU maps for a WRX.

So... I apologize for the situation and for making you hot over this, Spule 4. If it's any consolation, I did learn from the information in the thread, and I'll think about warped rotors differently now. At the end of the day, I think we're basically a bunch of guys interested in oddball stuff like the Honda Fit. The information and experiences we have are worth more than arguing over whether or not rotors warp.

 

Wow, I thought I was a nut for having a Volvo performance head in the house one winter to tinker with.....do I need to mention this was before I was married? I also rebuilt a few Citroen DS parts in a Ohio University college dorm room...I could go on....

No harm, thanks for the debate! Sorry if I came off as a pompus old ass....well, honestly, if I did, it is because I am!

edit, I cannot spell worth a <bleep>

 

Honda Jazz and City have bad brake rotors. I can feel my brakes wrap in about 15K. In my older car from the first day I bought I felt it's wrapped but only I felt it in high speed like 120-up kph. Later on I took them to the machine shop to skim it and gain it wrapped after driving like 190K I have changed and what a diffrence, and don't forget you rotors can get wrapped if you go car washing and your rotors are hot.

 

i guess i had some hotspots in my rotors and i took it in to the dealer because i had some pedal vibration. they ended up giving me brand new brakes and resurfacing my rotors for free under warranty I only had 12,000 miles on the car so guess that means i should take it easy on my brakes.

 

Mine just started pulsing at highway speeds- live in the mountains, don't notice it in town, only with 50-70mph downhills when brakes needed. In my experience with Honda rotors, this is the beginning, and it's gonna get worse. FWIW, the service mgr here agrees that hilly driving is hard on Honda brakes, and in the three I've owned, I agree.

Off to new rotors I guess, but we'll see.

 

Interesting StopTech article. All I can add to the "Do Rotors Warp or Not" debate is my own personal experience. Several years back, I adopted the practice of retorquing my lug nuts (with a micrometer type torque wrench) to spec any time a wheel is removed for maintenance.

Additionally, any time I take delivery of a new vehicle, the first thing I do is retorque the lug nuts. The brakes on my 04 Odyssey with 58K miles still felt like new with absolutely no vibration the day I traded it in.

This practice takes a bit of initiative, but it has always paid out well for me.

 

Took the words right out of my mouth. Even torque on all the lug nuts creates a perfect balance of preasure all around the rotor and this even preasure keeps the rotor from moving unevenly against the pads and this prevents them from warping under uneven preasure. I keep all my lug nuts at 100lbs (aftermarket aluminum nuts on my aftermarket wheels) and I drive my car hard almost every day, and I've also taken it once to a track day with 10 20 minute sessions and I have no problem with my brake rotors warping, my Hawk HPS pads do squeek when they are cold but this will apply to any track spec pad during daily driving, once they are hot no problems at all.