Disc-brake steel?

[ManDownUnder]

What grade or spec of steel are disks made of - where can you get it and at what price?

hmmm???

[jrandom]

See Skunk's recent thread on discs.

"Disc brake discs are commonly manufactured out of a material called grey iron. The SAE maintains a specification for the manufacture of grey iron for various applications. For normal car and light truck applications, the SAE specification is J431 G3000 (superseded to G10).."

[Colapop]

Where can you get it? What does it cost? How hard is it to machine?

Theoretically speaking, if the stell could be sourced, and can be machined, is it a cost effective solution to get new disks machined instead of buying new?

[imdying]

What grade or spec of steel are disks made of - where can you get it and at what price?

hmmm???

You could look for some centrifugally cast iron, but it's not worth your time. Discs are cheap to buy, you'd be hard pressed to spend more than a $1500 kitting out an entire sportsbike with discs, just do it

[imdying]

Theoretically speaking, if the stell could be sourced, and can be machined, is it a cost effective solution to get new disks machined instead of buying new?

Nup, not even close. The Waihi guy has spent a long time at it, and by all accounts for anything other than a commuter they're still crap.

[Colapop]

You could look for some centrifugally cast iron, but it's not worth your time. Discs are cheap to buy, you'd be hard pressed to spend more than a $1500 kitting out an entire sportsbike with discs, just do it

Yes I think I should just do it... pluck $1500 out of my *** that is... Never hurts to ask the question. Thanks for the info anyway, I spose I'll just keep working weekends...

[imdying]

The alternative to being a slave to the maintenance schedule your riding style and choice of bike demands, is to buy a GN250 New discs would (and I would be surprised if $1500 didn't get you OEM discs and pads) probably last the entire length of time you plan to own the bike, so it's money well spent (imho).

[Colapop]

Not to do with riding style etc... my bike is just old and needs them replaced... I'm just the unfortunate bugger that gets to do it!

[Grub]

Nup, not even close. The Waihi guy has spent a long time at it, and by all accounts for anything other than a commuter they're still crap.

Well sort of. He starts with rolled steel and works it flat. His own statement when you buy is that they will not stand up to hard riding but are perfect for commuting. So he states what he sells and the limitations of them - thats a fair deal. They are affordable. I don't agree that $1,500 is cheap at all!

The bit I'm not that flash about is ... we just got some for the '90 CBR600 and they look terrible and weigh twice as much as the originals. He's not machined all the surplus metal out of them.

[imdying]

Not to do with riding style etc... my bike is just old and needs them replaced... I'm just the unfortunate bugger that gets to do it!

Ahhh, just your choice of bike then Seriously though, you'd be surprised... I've removed OEM pads from some cars at 130,000kms, with a good chance they were there from day one... other people, 2000kms and they've toasted a high grade replacement set

Not only that, we just got some for the '90 CBR600 and they look terrible and weigh twice as much as the originals. He's not machined all the surplus metal out of them. The Grub isn't really impressed.

I spend a little time with brakes, and as a result I get to see a few... I've yet to find anyone that was satisfied with the Waihi made ones. That's not to say that they don't satisfy some people, naturally I only see complaints or problems that need fixing, but still, you can draw tentative conclusions.

[ManDownUnder]

Where can you get it? What does it cost? How hard is it to machine?

Theoretically speaking, if the stell could be sourced, and can be machined, is it a cost effective solution to get new disks machined instead of buying new?

Col - what thickness and diameter are the disks you want?

[Animal]

I went through this exercise a couple of years ago... The discs on my TL needed replacing, and I decided I'd design and make my own. The design and manufacturing part was easy, the material was a major issue. I spent weeks researching the best material and concluded that bike discs have a significantly lower thermal tolerance than car discs due to their lower thickness, weight, thermal mass, higher performance requirement, resistance to distortion and a bloody raft of other critical parameters. This didn't put me off though, and I tried to source a piece of material in NZ. Waste of time. I would have to import a quarter sheet from Australia, which would've cost well over $1600, and that was before I even switched my CAD computer on. Then, cutting the disc blanks out of the sheet became an issue. Laser cutting hardens the edges, CNC milling is too expensive, so high-pressure water-jet cutting was the answer. I discussed this with the only engineer here in Ch'ch who has water-jet gear (and is a hard-core biker himself). He was completely honest about the time and cost involved, and talked me right out of making the discs myself. The costs would have been astonomical, and not for the faint-hearted. In comparison to Suzuki OEM parts, it would've cost me just under five times the price to make my own.

Google Fabrum Solutions for info on water-jet profile cutting.

[Colapop]

Col - what thickness and diameter are the disks you want?

They are 5 stud, 310mm disks. I posted a thread here about it.

[Animal]

Have a look at this supplier...

http://www.ebcbrakesdirect.com/bike/info.asp

[Coldrider]

I got a full floater disc from vicwreck in melbourne for my ZX, cost $200AU plus shipping & ins, had it on the bike 4 days after the email.
I had warped my left rotor on the road from cardrona down to the main highway adjacent to arrowtown.
It's is as good as the one not replaced and have mega miles in them.
Incidentily I replace the pads with OEM for a fraction more dollars to keep the original feel, soft pads & hard discs are the answer.