Disc made for bikes

[nudemetalz]

Hiya,

Has anyone here ever had any discs made for their bike by an NZ manufacturer?
If so , what can you tell me?
I'm in the process of getting some made and was talking to a bike shop and they told me that I may have major hassles with the quality of these discs from the NZ manufacturer.
I don't really want to take a chance with discs for a big heavy cycle like my '10.

What do you peoples reckon?

[Zapf]

ermm good point... are bike disks just a thick stainless steel plate or is there more to it?

[Ixion]

I'm fairly sure they are just a thick stainless plate. With some mounting holes and maybe slots etc .But the devil is in the "just".

The plate has to be absolutely flat, And exactly the same thickness . To VERY fine limits. And rotationally true about the mounting holes. And it has to stay that way when heated up (localised heat, too) and cooled down. And when subject to very high physical stress.

That call , I suspect, for some pretty good engineering.

[nudemetalz]

Apparently but still not as simple as that. The discs are normally made out of a special type of steel which has the grain going a certain way. This is so you don't end up with warpage which normal sheet steel can produce.

[Warr]

There is a guy in Waihi selling them. And made locally....
Have a look at the thread I started regarding them just recently.

http://www.kiwibiker.co.nz/forums/showthread.php?t=20393

[nudemetalz]

eerrr....that's the one I was trying not to refer to.........

Umm,...should I still proceed or say to him don't bother.......??

[Ixion]

Does the Waihi guy only do stainless? For some reason (absolutely no logic or evidence) I have convinced myself that cast iron would be much easier to get running true, and probably give better braking (goes rusty of course).

[curious george]

The Waihi can do both stainess and iron, supposidly the market lusts for stainless....
Milky was doing something like this a while ago, ask him?
I have a rear disc from him, seems fine. He couldn't do the front as my carriers are dished.
Talk to the guy about warranty/reliability/etc.
If you are not satisified, EBC make nice ones....

[nudemetalz]

I sent a very frank email to him :-

QUOTE:

Hi,

I have some concerns...

I got chatting and it seems some people have had some issues with your discs.

Question is am I going to be entirely satisfied with the discs?
What sort of warranty do you offer?
Can you assure me that they won't warp. (I'm definitely not racing the bike BTW)?

With my bike being a ZX-10, ie big and heavy, I really don't want to gamble with brakes.
If you can't assure me then I'll have to cancel the order and fork out and buy OEM ones."


Maybe I was a little harsh, but direct and straight to the point is how I like dealing with things.

NDMz

[Warr]

I sent a very frank email to him :-

QUOTE:

Hi,

I have some concerns...

I got chatting and it seems some people have had some issues with your discs.

Question is am I going to be entirely satisfied with the discs?
What sort of warranty do you offer?
Can you assure me that they won't warp. (I'm definitely not racing the bike BTW)?

With my bike being a ZX-10, ie big and heavy, I really don't want to gamble with brakes.
If you can't assure me then I'll have to cancel the order and fork out and buy OEM ones."


Maybe I was a little harsh, but direct and straight to the point is how I like dealing with things.

NDMz
Go with what makes you happy NDMz :)

When I got the bad news that I needed to spend MORE money I started with buying a dial gauge, so at least I was prepared and able to discuss my concerns with the man. Being local helped. At the end of it all I still couldnt see myself shelling out OEM prices.
I'd happly go 2nd hand, But I'd take either the whole bike or at least the wheel in and put the onus on the shop that if they arent running right they can keep them.

If 2nd hand would suit you check out
http://www.motorcyclemarketplace.co.nz/

[noyz]

or you could go ebay they have some for $70 US
http://search.ebay.com//search/search.dll?from=R40&satitle=ZX-10+disc

[Sniper]

I'm fairly sure they are just a thick stainless plate. With some mounting holes and maybe slots etc .But the devil is in the "just".

The plate has to be absolutely flat, And exactly the same thickness . To VERY fine limits. And rotationally true about the mounting holes. And it has to stay that way when heated up (localised heat, too) and cooled down. And when subject to very high physical stress.

That call , I suspect, for some pretty good engineering.

What Ixion said, but I am still fairly sure that I could make you a good set of disks with some tin foil, a hammer, some no8 wire and a garden shed. They don't come with a guarentee and are untested.

[nudemetalz]

or you could go ebay they have some for $70 US
http://search.ebay.com//search/search.dll?from=R40&satitle=ZX-10+disc

Unfort they are for ZX-10R's....not my baby, but thanks anyway.

[nudemetalz]

Well I spoke to Graham from Powermotorcycles thins morning. He has assured me that I will be completely satisfied with my discs and they also carry a 12 month warranty.
So I am going ahead with them and I'll report what they're like when I get them and fitted.

[imdying]

The manufacture of discs is indeed tricky (well duh), and it was popular for a while to cut a wafer off of a feck off large piece of centrifically cast cast iron rod. They were then cut to shape, and parallel surface ground. Apparently it was reasonably difficult to get them within tolerance (2 thou of runout). Even when this was achieved, as someone mentioned above, the grain of the metal is still critical to high performance applications. Inconsistencies in the structure of the metal (on a fairly low level) resulted in highspots due to different expansion rates around the disc. Add to that the fact that some pads are particular about the disc compound (that's not a typo), and work less than effectively with odd metals). All in all, if the warranty is a year, and the price is half (or less) than OEM they might be worth a try. However, bike discs are often less than $500 each, and last a bloody long time if not to abused :D

As an aside.. Commodores had a problem with high spots forming once upon a time. GM used to cast them 5 at a time, and by the time they were pouring the molten metal for the 3rd, 4th, and 5th discs, the molten metal had cooled so much as to make the metals make up inconsistent. Disc Brakes Australia however never had this problem, as they were casting them two at a time. That's how particular discs can be :(

If it was a bike I loved, I'd buy the OEM ones.

[onearmedbandit]

imdying, you clearly don't have any idea what you're talking about.....

[nudemetalz]

Well I believe that they are competitively priced and he will stand by their quality.

[Mattyc]

ROFL:doobey: :doobey: :doobey: what ya'll been smoking on

I would not fuck around with brakes, specially on a zx10 of all bikes, buy the proper discs or go for something aftermarket that is PROVEN trialed and tested. Ask some racing guys or something..

the thing about bike discs is from new to min thickness is fuckall..... I wouldnt mess with this voodoo shit

[nudemetalz]

Why assume that these discs will be crap?

[imdying]

heheh, sorry if picking on Holdens hurt your feelings oab :D I must know something... you've let me drill a lot of holes in suzy :P

The assumption is just that they're potentially crap, where as the OEM ones can be assumed to be perfect for the job.

[Mattyc]

are you doing it to save money or because you are not happy with the way your bike stops

obviously the factory brakes are tested to a certain level or performance.

[skidMark]

either they are more to them than you think or the bike shops are just trying to sell you a genuine one :blink:

[nudemetalz]

are you doing it to save money or because you are not happy with the way your bike stops

obviously the factory brakes are tested to a certain level or performance.

Well I ain't really happy with my discs 'cause one measures 2.6mm and the other 2.7mm......

And, no, I bought it like that !!!

[Mattyc]

jesus thats thin. so you gonna replace them both ?

[skidMark]

Well I ain't really happy with my discs 'cause one measures 2.6mm and the other 2.7mm......

And, no, I bought it like that !!!

mate get that replaced asap if your pads grab to hard or you have to jump on them hard one day you might shatter your disc be careful mate and try to avoid riding in the meantime thats so low it's scary....they gave it a warrent like that!!!???... :blink: :blink:

[nudemetalz]

Don't fear guys !!

I bought it like that and am replacing them both before I get it VIN'd. The last owner used to get WOF's from a bike shop with them like that..... SCARY !!!!

And apart from a couple of very small quick rides I'm not riding it til the new discs are on.

[T.W.R]

:corn: :corn: :corn: :corn:yeah i know :shutup: F1RA:blip:

[slopster]

I used to do a bit of downhill mountain biking and a mate had some stainless discs cut for his brakes by a local engineer. They worked perfectly until they got to maximum heat in a downhill race and warped. The front one jammed in the caliper and locked the front wheel and shattered the disc. I wouldn't trust a disc that wasn't at least made by a well known aftermarket manufacturer.

[nudemetalz]

umm,....thanks Slopster.....

[avgas]

it depends on how the disc is cut aswell.
that guy at waihi's disc's will be safe - but may wear down faster thats all.
of course you could get the OEM ones from Japan :whistle:

[nudemetalz]

I totally agree with you, Avgas.

The OEM ones were about $800 each !!!
Not cheap !!

[imdying]

Wow $800! Still, kind of nice that kwaka still have them :) You're armed with the info, and the price is right. Considering that this is a small country, and noone here has said 'my mates mate had some and they killed him', they sound like they're worth a go. Definitely report back on how they went though!

[Kickaha]

I used to do a bit of downhill mountain biking and a mate had some stainless discs cut for his brakes by a local engineer. They worked perfectly until they got to maximum heat in a downhill race and warped. The front one jammed in the caliper and locked the front wheel and shattered the disc. I wouldn't trust a disc that wasn't at least made by a well known aftermarket manufacturer.

We have done the same thing with no problems at all (recreational use), had them laser cut and surface ground and they have been on the bike for the last 2 years

We have also had discs laser cut out of stainless for a pre82 bike which used them for a year with no problems and won the championship, we have also had some done in mild steel and used them on trailbikes and 250 Superkarts for the last few years

The only problems we have seen with them warping were when there were caliper problems which caused them to dish a bit

[onearmedbandit]

Couldn't care less for Holdens or Fords imdying. You know that. In fact I think it was you that gave me this handy saying, 'same shit, different bucket.'

[nudemetalz]

Wow $800! Still, kind of nice that kwaka still have them :) You're armed with the info, and the price is right. Considering that this is a small country, and noone here has said 'my mates mate had some and they killed him', they sound like they're worth a go. Definitely report back on how they went though!

I do that for sure. Graham wants his rep back and I said that if they live up to expectations, ie they stop the bike without killing me !!! , then I'll write a favourable report.

[vifferman]

Ignore the naysayers, Nudemetalz - I'm sure they'll be fine. And like Kickaha said, it's usually the calipers that cause problems.
I've had two bikes with brake problems; the VF500 had one front disk that was very worn (sticking caliper) and I replaced them with secondhand NR250 disks (same size / mounting, but drilled instead of plain). I couldn't get a good righthand one, so bought two lefthand ones (apparently righthand disks for many bikes were problematic). The holes in the righthand one were back to front, but no-one noticed, and it also had a slight warp, but it worked fine, and infinitely better than badly worn disks. This is the same as in your case: the disks you're getting, even if they're not up to the same standard as OEM Kawasaki ones, will be infinitely better than badly worn ones, and much safer.

When I bought the VifFerraRi, it had two mismatched disks. The one on the right had marks from the pad rusted into it, and the brakes pulsed noticeably when braking gently. I was assured the disk was not warped, and that this would scuff off. Now, after a year it has come right, and that only because when I had new brake pads fitted, it turned out the righthand caliper had sticking pistons and one pad was worn out. Once the pads wore in, the brakes came right.


For some reason (absolutely no logic or evidence) I have convinced myself that cast iron would be much easier to get running true, and probably give better braking (goes rusty of course).
That's true.
Brakes used to be cast iron, till the Japanese manufacturers decided the rusting was unsightly, and started making and fitting disks made from stainless steel. The latter is generally inferior in that it is harder (so offers less friction), harder to manufacture, and I think (dunno this for sure) that it's more prone to warping, due to the way it reacts to intense heat.

[nudemetalz]

Thanks Vifferman.

All I want is the ZX to be on the road all legal.
I mean to say the NZ-250 is fun to ride, but it doesn't have over 120hp !!

I am also certain that the brake discs will be fine. He's been making them for a long time now and I'm positive he knows his stuff.

I will put in new appropriate pads as well when I get the discs.

[vifferman]

I will put in new appropriate pads as well when I get the discs.
And check the pistons? And brake fluid? :yes:

[nudemetalz]

Oh, that too,.. :)