Brake discs

[sinto]

I'm on the search for a set (front and back)  of brake discs.
I've searched ebay but only getting cheap rubbish from HK
Anybody got any links of any places I should try?
Cheers.

[Val]

Hi Colin,

my front discs need change soon too, here is my search so far:

First the part codes, in fact many front brake discs for different brands like Cagiva, Ducati and Moto Guzzi  will fit our Yamaha according to Ferodo part catalog Ferodo part number is FMD0121:

   

	COMPETITOR XREF
BRAKING	STX15
EBC	MD2001LS/RS
NEWFREN	.DF.5167 AF
EQUIVALENT OE #[/t] OEM 3EN 2581T 00 OEM 3CV 25830 10 OEM 4HM 2581T 11 OEM 3 HE 2581T 00 OEM 3RG 2581T 00 OEM 3CW 2581T 00 OEM 3CV 25830 00 OEM 4HM 2581T 00 OEM Moto Guzzi 306133000 OEM Yamaha 4HM 2582T 21 OEM Yamaha 3CW 2582T 00    http://ecat.ferodoracing.com/motorcycle/brake-discs/FMD0121 Here is the cheapest pair for 2 Ferodo quality discs I have found so far £240: http://www.ebay.co.uk/itm/Yamaha-TDM850-1996-2001-Ferodo-Front-Brake-Discs-Pair-/270931511302?pt=LH_DefaultDomain_3&hash=item3f14c6c806 Here are some EBC quality ones 205 EUR about £144 for one disc so the pair would be about £290 does not make much sense to me compared to Ferodo which IMO are one of the best: http://www.motorparts.nl/index.php?main_page=product_info&products_id=1923&number_of_uploads=0&cPath=637_638_639_649&language=en and here from EBC UK: http://ebcbrakesdirect.com/store/Motorcycle/vt/2/mk/86f0133a-3fba-4a6a-9a67-8bad9a2c748f/md/47f3f145-9000-4393-96ee-023f1f4d1327/vid/dcc9d217-615a-47ff-a22e-51d237a7b1ae Here are some good Chinese ones from ARASHI moto I have not decided but may try ones about £130 for 2 discs pair: http://www.madhornets.com/front-brake-disc-rotors-yamaha-fj-fz-fzs-fzr-tz-tdm-trx-xjr-250-400-600-750-850-1200-1989-2003/?gclid=CJCn0eKq87kCFVIPtAodSn8ApA

Here is a review from a guy running Arashi discs and still alive: 

www.bikersoracle.com/cbr600/forum/showthread.php?s=16a1794cfadc98a540c69a9b8f79a23c&t=24084&page=1

[Paulfzs]

ive got a used set here in a box, planned on fitting but it seems so much effort!

[sinto]

Cheers Val
I'll have a more in depth read later but the Chinese ones look just as good, got me thinking now

[sinto]

ive got a used set here in a box, planned on fitting but it seems so much effort!

Used? Thought you were going to offer me a new set there Paul

[darrsi]

Obviously I can't tell for sure, but the Arashi ones look suspiciously like the discs I have on my bike, but under a different branding.
If it is them they've served me very well with no problems, and are a tiny bit thicker than others are, about 6mm from memory.
But, no guarantees they're the same.

I'll try find a photo to show you.

[darrsi]

Obviously I can't tell for sure, but the Arashi ones look suspiciously like the discs I have on my bike, but under a different branding.
If it is them they've served me very well with no problems, and are a tiny bit thicker than others are, about 6mm from memory.
But, no guarantees they're the same.

I'll try find a photo to show you.

Nope, they're different, scrub that!

Word of caution, you buy anything from China and they're total shite, then good luck with getting a refund, after you've paid a fortune in return postage, then wait months, or forever!
Not advisable.

And DO NOT throw away your old discs unless they are totally fooked, you never know when they can get you out of trouble.
Trust me, been there, done that.

[Jules-C]

Most of the replacement disks are thicker than the Yamaha ones, Yamaha are I think 4.5mm but replacement ones are usually 5mm, even though they often put claims about weight saving on their websites!  Check the price of Yamaha ones they often aren't much more expensive and usually last longer.  For the difference in price and problems with refunds from China I'd stick to known brands

[Fazerider]

The EBC ones I bought are both thicker and lighter than OE, the centre is alloy which is where the weight is saved.

[darrsi]

The EBC ones I bought are both thicker and lighter than OE, the centre is alloy which is where the weight is saved.

Would it matter at all if they're heavy or not on a road bike?
I doubt it very much, and i can't imagine it being noticeable either.


There's something rather reassuring about certain items that are heavier. 
 

[Paulfzs]

ive got a used set here in a box, planned on fitting but it seems so much effort!

Used? Thought you were going to offer me a new set there Paul

i wish they where new haha, i need to check to see if mine need changing, im sure they do though

[sinto]

I only recently noticed my discs at the front are a bit warped as when taking the wheels off for my recent forks and tyre jobs, when the calipers were off the wheel ran smooth as anything But once I put the calipers back on, it was far more harder to turn the wheels,  although it turned, wasn't as smooth. I know there is some friction but this seems way to excessive for my liking.
So I had a real close look at the pads and they seem to be wearing at an angle
Back one isn't as bad but if I'm doing the front, may as well do the back one too.
Checked them with a laser pen and the discs aren't true So on a hunt now for a decent set.
Looks like I'll stay away from the wavy &  Chinese etc would like to stick to original I think

[Chris]

I like my Armstrong wavy discs.

Chris

[darrsi]

I only recently noticed my discs at the front are a bit warped as when taking the wheels off for my recent forks and tyre jobs, when the calipers were off the wheel ran smooth as anything But once I put the calipers back on, it was far more harder to turn the wheels,  although it turned, wasn't as smooth. I know there is some friction but this seems way to excessive for my liking.
So I had a real close look at the pads and they seem to be wearing at an angle
Back one isn't as bad but if I'm doing the front, may as well do the back one too.
Checked them with a laser pen and the discs aren't true So on a hunt now for a decent set.
Looks like I'll stay away from the wavy &  Chinese etc would like to stick to original I think

Slow down a bit. 


They wear at whatever angle is necessary, even more likely when you have floating discs and 2 pistons in each caliper that will adjust in and out accordingly.


"Warped discs" is a term used too loosely and not always the case.
If you used crappy cheap pads for example and had heat transfer causing parts of the pad to transfer to the disc, then that would cause a "hot spot" which in turn can cause a grabbing sensation every time the pads hit it, as it is part raised on the disc, and can give a similar feeling to a warped disc.


Another silly one but very easily done is when you buy new discs they have a sticky oily film on them for protection.
This needs totally wiping off with brake cleaner before using otherwise that can cause a sticking effect too. It "should" just burn off eventually, but by then you may have contaminated your pads so will still get a shitty feel on the brakes that won't quite feel as good again as they were.


I had a problem a few years back where i virtually ended up changing the front end of my bike due to a juddering "warped disc" feeling, a bit like braking on cobble stones, and the culprit eventually turned out to be the only possible thing left that i hadn't changed, which was the brake lines.
If they had been standard lines i would've thought about changing them much earlier, but they were upgraded braided ones and as there were no leaks or visual damage i totally overlooked them.  Lesson learned.


As for the pads being at an angle, i would look more into your calipers, there is a possibilty that you may have issues with sticking pistons, and now is a good time to learn how to clean them up while there is reasonable weather, 'cos unless you have a decent garage or cover, it's a shit job out in the cold.
I've cleaned mine so many times i can do them on the bike without removing the calipers or fluid, just for a general clean up and for fresh rubber grease.
Do that a couple of times a year and not only do you get good at it, but it keeps piston trouble at bay for much much longer.


Other reasons for your pads rubbing when putting back on are firstly because you've simply disrupted them, even a fraction of a millimetre will change the angle of the pads so the lines on the discs and the pads will now not line up causing friction.
This is made much worse if you take the pads out and put them back in different places, they will need bedding in again and much more resistance will be felt and heard.


If you ever do get new discs, which i doubt very much you need anyway, then make sure the surface of the wheel hub is TOTALLY free of any built up crud or dirt, it needs to be spotless so the new discs lay perfectly flat on the wheel.
And use a torque wrench on the wheel nuts, that's very important.
Good luck with the rear caliper bolts, be prepared for disaster as they tend to weld themselves to the wheel hub,and can be a complete and utter bastard to remove. Heat seems to be the main weapon of choice, i personally had to buy another wheel last time. 


Just an important pointer though, if you really did have a warped disc(s), then with these decent calipers that are on these bikes if you grabbed a handful of front brake you would find yourself doing your very best Superman impression when it totally locks up! 

The fact you haven't mentioned anything of the sort, or even moaned about a juddering or pulsing feeling when braking suggests to me that your calipers are due for at least a personal clean up by yourself, or possibly even an overhaul.


Brake discs are one of the more expensive things to buy, along with the rear shock, but if you don't need it then no point in wasting money, 'cos if your piston still doesn't function as it should then you won't be gaining anything whatsoever, and could even score the new discs which you really don't want.


For the record, if you do put new discs on then ideally you want new pads too, and a perfectly functioning caliper so they all work in harmony straight from the off. 
 

[Pickle]

Colin,


Happy to pop through the tunnel with a micrometer and give you a second opinion. I agree with Darrsi that you could be jumping the gun here and possibly have a sticking piston on one of the calipers rather than a warped disc.
If you had a warped disc you would feel it.

[RMT1983]

Ive got a set of ebc front discs for sale if any good to you???

Message me if so buddy............

[sinto]

Good points darrsi and I'll be stripping the whole lot down over the winter months, although with the Sumner we're having in Scotland that won't be too far away


Anyways....
When I had the wheels off, I only quickly looked at the pistons, all were moving but admitted, I didn't push them all the way out. Whether they're all going out at the same level is hard to judge.

The reason I think the discs are warped is that when looking from front of the bike, with calipers removed there is movement when I spin the wheel, the discs don't run true. Now I'm no engineer, but I don't think that's right.

Yes, there's different wear on the pads,  is that due to the pistons or that the discs aren't running true?


Pickle, I've sent you a pm

[Chris]

Give this video a watch and see if it might apply to your discs, made a good odds to mine when one of the discs wasn't sitting quite straight. this helped free it up and worked fine again after. 



Chris

[Pickle]

Good vid Chris

[sinto]

But unfortunately I can't do that with my discs
I don't have a hole right through mine

[darrsi]

Good points darrsi and I'll be stripping the whole lot down over the winter months, although with the Sumner we're having in Scotland that won't be too far away


Anyways....
When I had the wheels off, I only quickly looked at the pistons, all were moving but admitted, I didn't push them all the way out. Whether they're all going out at the same level is hard to judge.

The reason I think the discs are warped is that when looking from front of the bike, with calipers removed there is movement when I spin the wheel, the discs don't run true. Now I'm no engineer, but I don't think that's right.

Yes, there's different wear on the pads,  is that due to the pistons or that the discs aren't running true?


Pickle, I've sent you a pm

If you have warped discs, looking at them will mean nothing, unless they're shaped like a breakfast bowl.


The very first thing you notice will be when even a slight press of the front lever causes the bike to start juddering/pulsing up front, in a stop/go sensation.


Pull the brake lever much harder and the pads will grab the warped part and you will "STOP".......literally.


You still haven't described this at all, and it would be the FIRST thing you would complain about.

[Chris]

Ah yeah, sorry forgot the OEM discs didn't have holes all the way through the bobbins... maybe you could use a g clamp to tighten on either side of it rather than a bolt and nut gripping it... wouldn't be as good but might work...

Chris