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/sh...ad.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/searc...tle=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/searc...tle=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

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.