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 ! :eek5:

[Gixxer 4 ever]

You get a lot of heat with hard or long braking but you get excessive heat when the calliper does not return and lets the pad 100% off the disk. You should never have rubbing on a front disk. If you do look at the dust and pot seals. Sometimes the dust seal turns inside out when it has gripped the piston and this prevents it from returning. At this point you should strip clean and rekit the wheel cylinders. If you have never done them before it would be better to get a shop to do it. There are catches and bleeding brake can be tricky if you have never done them before. So can master cylinders for that matter. try second hand places. I have had great success with second hand. $50.00 for a front disk for my XT 250. Paid $300.00 for a set of two for my GSX_R. If you want contact details P/M me

[John]

Thanks for the help, I talked to the mech and he said he seriously doubts that I did it myself - both the disks are warped the right one the worse, So I am going to get hold of the dealer (tried all day) to get them to give me the go ahead on getting the new parts in.

Also the mech was doing a strip down check for me, and said that the valve clearances looked like they had never bein done before, and he didnt have enought shims to finish them, so thats where my fuel was going I supose, what sort of dangers occur in a majority from bad valve clearances? I know a few but only the general ones.

[F5 Dave]

Discs get hot & the metal expands at uneven rates from the inner to the outer so they warp or ‘cone’

4mm is huge (sure it wasn’t 0.4mm?), like they would lock up when you put them on like a jackhammer. If you’ve been riding like this the steering head bearings are likely to be toast.

4mm sounds like you’ve had the tyres changed by the apprentice learning how to use the tyre machine.

[John]

Discs get hot & the metal expands at uneven rates from the inner to the outer so they warp or ‘cone’

4mm is huge (sure it wasn’t 0.4mm?), like they would lock up when you put them on like a jackhammer. If you’ve been riding like this the steering head bearings are likely to be toast.

4mm sounds like you’ve had the tyres changed by the apprentice learning how to use the tyre machine.

Thanks for that yes I was wondering if a tire change could have being a culpret as it had new tires on purchase, yes its definatly 4mm, I can not beleave it got a warrent like that, also the left one is out by 3mm.

And I know it was like it when I bought it, because I felt the feedback but I never new that the disks would have being warped, I'm still new to biking and just figured the disks were more looks that power, I even commented to everyone about the shit brakes, even talking to justsomeguy on the ride I said to him how the ZZR had better brakes, steering head bearings, man this is slowly racking up in dollars as it goes on thanks for the heads up I will make sure that they check it, that might explain my crappy cornering confidence with no fell up front.

[inlinefour]

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

I thought the whole reason of having a bike was to give it....

[F5 Dave]

Brakes that warped will scare the crap out of you. Kawasaki’s are also prone to coming with very little fork oil for some crazy reason. New oil may help the front end.

As an aside try letting go of the brakes slowly/smoothly when you go to tip into the corner else it unsettles the bike if you brake hard & just ‘let go’ -front forks will pogo a while :banana: , + look around the corner quite a way, which is the hardest thing to learn & keep doing.

[Motu]

I thought the whole reason of having a bike was to give it....
That's what I think too - so when I hear someone complaining about how stuffed their bike is I'm a bit puzzled....like,that's a good sign isn't it?

[John]

That's what I think too - so when I hear someone complaining about how stuffed their bike is I'm a bit puzzled....like,that's a good sign isn't it?

I dont consider paying a crapload from a dealer and getting a half alive bike a good thing myself, but hey if your keen on that sort of thing full points to you.

[Motu]

I dont consider paying a crapload from a dealer and getting a half alive bike a good thing myself, but hey if your keen on that sort of thing full points to you.

Well,I don't ever put myself into that position - but if that's what you like....bend over!

[John]

Well,I don't ever put myself into that position - but if that's what you like....bend over!
Man, your a charming fellow.

[Storm]

He is after all, the site "Evil Clown" . He's got a reputation to live up to now

[John]

He is after all, the site "Evil Clown" . He's got a reputation to live up to now
I dont hold it personally against him, I know he loaths for love deep down. lol

[WINJA]

MY GSX750 HAD WARPED DISCS, I STRIAGHTENED THEM WITH A CRESCENT , I JUST LEFT THEM ON YHE RIM AND BENT THEM STRAIGHT, I KNOW ITS NOT PERFECT BUT WORKS ON NON FLOATING DISCS

[speedpro]

Discs get hot & the metal expands at uneven rates from the inner to the outer so they warp or ‘cone’

4mm is huge (sure it wasn’t 0.4mm?), like they would lock up when you put them on like a jackhammer. If you’ve been riding like this the steering head bearings are likely to be toast.

4mm sounds like you’ve had the tyres changed by the apprentice learning how to use the tyre machine.
I'm with Dave on this. I have real problems believing you could ride a bike with discs with '4'mm runout. I've warped discs on my bucket. They were under "."4mm and it was nearly unrideable. Certainly anything other than very gentle braking was asking for trouble, of the over the front kind.

[John]

I'm with Dave on this. I have real problems believing you could ride a bike with discs with '4'mm runout. I've warped discs on my bucket. They were under "."4mm and it was nearly unrideable. Certainly anything other than very gentle braking was asking for trouble, of the over the front kind.

Nope definatly 2mm out on left 4mm out on right I check 3 times because I couldnt beleave it, abit freaky - he said the pistons took most of the preasure and are probably half dead as well, since they are full floating disks I didnt notice it as much, just in general shit brakes, and probably shit pads.

[Teflon]

Honda disks are shit.

[John]

Honda disks are shit.
Thats why I dont let friends buy honda.

[Teflon]

Thats why I dont let friends buy honda.

Warped a few disks on my FZR, so i guess Yamaha are shit too.

[John]

Warped a few disks on my FZR, so i guess Yamaha are shit too.
All bikes are shit except harleys, its just a fact hahaa.

[F5 Dave]

Yeah. Right on bro. That’s ‘cause those fiendish japs make their bikes out of shit metal,

unlike the Americans who use good ol’ dependable pig iron.


Hey, it's my 1000th post!!!
:banana: :banana: :banana:
:wari: :wari: :wari:

awww :grouphug:

[inlinefour]

That's what I think too - so when I hear someone complaining about how stuffed their bike is I'm a bit puzzled....like,that's a good sign isn't it?

If you have ahalf a clue about bikes, you stuff it, you fix it. If your looking for a bike and its stuffed, then you walk on :whistle:

[F5 Dave]

If you have half a clue about grammar ‘you are looking’ even ‘you’re looking’, but not ‘your looking’.