Disk Warping

[John]

Well how bad have you managed to get your disk warped.

I took my bike in for a service, becuase as a consensus its running shit as, i.e oil turned black, high fuel consuption (130k to a tank) surging, clutch shitting out, dripping oil, shit running and generally just pissing me off incredibly.

I asked him if he could check the front rotors, as I felt alot of feedback at speed, and I call back to ask him to replace something else, and he kindly informs me that the disk is out by 4mm.

Now I dont know how a disk warps other than in a crash, so the way I see it I got a warped disk from purchase, and it got a WOF like that. wow.

But seriously how can they warp other than in a crash its got me licked.

I mean 4mm is a considerable amount, even the guy (mark at shaws motorcycles bloody good dudes there) even said that it must have gone through a time machine and I'm a legend for still being able to ride it lol.

Oh well, Who knows.

[Motu]

Rotors warp from heat - plain and simple rider abuse,if they were perfect when you bought it then that puts the blame on you....

[John]

Rotors warp from heat - plain and simple rider abuse,if they were perfect when you bought it then that puts the blame on you....

But 4mm? isnt that a substancial amount of warping for a bike that doesnt sit in the sun or hasnt seen stoppie type breaking, its more of a question.

As its only 3 weeks old and hasnt even seen a fast ride yet.

[Two Smoker]

You think 4 mm is bad... my GSX-R600's is out by 25mm... but that was a result from a crash...

[Motu]

Yeah,that's a substantial amount of rider abuse alright...

[idb]

I understand that going through a puddle when the discs are hot can cause them to warp.
They weren't rubbing and heating up were they?

[John]

Nope they have not seen much water, a few showers and such, always keep my brakes maintained, but never really noticed the warping while cleaning the rotor.

It always has rubbed abit since I have had it but I know most bikes do slightly rub, but this was alittle worse so I dont know maybe it was my fault, but I some how doubt it I dont ride as hard as I did.

Its got me abit confused about how it warped so bad, I mean well personally 4mm is a substantual amount, and I think it was like it when I bought it because I always felt the brakes were real weak and 'bumpy' in comparrison to the ZXR.

If I have to pay for the rotor I will goto FGB they will get me one for 300$ so thats not that bad, considering for the orginal part it would be two times that.

Thanks for the help, I will have a chat to the mech about it.

[pritch]

I was talking to an Aprilia owner a week or three back and asked about his "wavy" disk rotors.

He said that he had to replace one because it was warped.

I think he said It was going to cost over a grand for the factory part.
So he replaced the pair for $500 from the local manufacturer.

[Motu]

What causes rotors to warp - coming to a stop after hard braking,and then holding pressure on the lever.This feeds excessive heat into one area of the rotor,distorting the disc and causing runout.

[scumdog]

Are vented discs more prone than non-vented?

[Wolf]

What causes rotors to warp - coming to a stop after hard braking,and then holding pressure on the lever.This feeds excessive heat into one area of the rotor,distorting the disc and causing runout.

So if you break hard then hold the brakes on, you stuff them? Bummer if you have to hold the brakes on if you're in danger of rolling.

[jrandom]

So if you break hard then hold the brakes on, you stuff them? Bummer if you have to hold the brakes on if you're in danger of rolling.

That's what the rear brake's for.

[Ixion]

So if you break hard then hold the brakes on, you stuff them? Bummer if you have to hold the brakes on if you're in danger of rolling.

I always like to brake hard enough that I actually finish braking a few yards before where I want to stop and then drive those last few yards under power. Better safety -a bit of braking distance in hand, easier to deal with idiot behind who can't stop, more options under power than there are braking, and it cools the brakes down. Rear brake does the final stop

[Wolf]

That's what the rear brake's for.

True. Do the rear drums have similar heat issues?

I seldom brake hard - generally tend to use the engine a lot and slow early for intersections, queues of traffic. Only had a few "throw out all the anchors" kind of stops. (The LS didn't go fast enough for "hard braking" most of the time.)

[Ixion]

True. Do the rear drums have similar heat issues?
..

Drums can distort from heat also. On the whole I think it was/is less of a problem. Heat build up is much greater because of the enclosed nature of a drum brake (causes fading, that's why disks are superior). But the mechanical strength of a drum, due its shape is far far greater than a disk. Disk is not inherently good shape for physical strength. I've seen brake drums glowing red hot !