Disc-brake steel? [Archive] - Kiwi Biker forums

jrandom

13th August 2007, 11:50

Colapop

13th August 2007, 12:05

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

13th August 2007, 12:06

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 :yes:

imdying

13th August 2007, 12:08

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

13th August 2007, 12:13

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:
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

13th August 2007, 12:19

The alternative to being a slave to the maintenance schedule your riding style and choice of bike demands, is to buy a GN250 :yes: 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

13th August 2007, 12:22

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

13th August 2007, 12:34

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

13th August 2007, 12:38

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 :o

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

13th August 2007, 12:38

Animal

13th August 2007, 12:40

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

13th August 2007, 12:50

Col - what thickness and diameter are the disks you want?
They are 5 stud, 310mm disks. I posted a thread here (http://www.kiwibiker.co.nz/forums/showthread.php?t=54590) about it.

Animal

13th August 2007, 12:51

Have a look at this supplier...

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

Coldrider

13th August 2007, 13:26

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.

Warr

13th August 2007, 13:48

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.
Jot me down in the "Unsatisfied Customer" coloumn

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.

If I had known that I wouldnt have a set of useless fronts in my garage now !

Ocean1

13th August 2007, 15:03

See Skunk's recent thread on discs (http://www.kiwibiker.co.nz/forums/showthread.php?t=55051).

"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).."

Warning: Bike disks are NOT made out of grey iron (or SG iron), they are a specific carbon steel. Iron's claim to fame (and the reason it's used for common cage duties) is that it's thermally stable (not overly subject to heat stress cracks) and structurally ridged. But it's brittle, and not very strong. If you made iron disks to the same dimensions as your originals they would be seriously structurally under-designed.

It's probably quite possible to source an equivalent steel to the OE disks (if you can identify it correctly) and a matter of a few minutes to draw and laser cut them. The issue of hardening is really only a problem on surfaces which will contact the pads (vent holes) and these can be post-drilled. For most disk designs I've seen the cut disk could then be finished on a surface grinder. Easy, if you can identify the correct alloy. If someone does that and delivers it here I'd be happy to make a set for someone to evaluate.

Animal

13th August 2007, 15:17

...if you can identify the correct alloy.

I did. It wasn't easy, as the OE Manufacturers don't like to share proprietary information - selfish bastards!:laugh:
It's certainly not Unobtainium, but exotic enough to make it impossible to buy locally, yet still prohibitively expensive to buy less than a couple of sheets at a time. Not too bad if I wanted to go into volume production.
After I'd added the costs of importing a suitable piece, getting it profile cut, finished and fitted with OEM floating buttons, it wasn't worth pursuing.

Ocean1

13th August 2007, 15:28

I did. It wasn't easy, as the OEM manufacturers don't like to share proprietary information - selfish bastards!:laugh:
It's certainly not Unobtainium, but exotic enough to make it impossible to buy locally, yet still prohibitively expensive to buy less than a couple of sheets at a time. Not too bad if I wanted to go into volume production.
After I'd added the costs of importing a suitable piece, getting it profile cut, finished and fitted with OEM floating buttons, it wasn't worth pursuing.

Oh I'm an expert at getting around such obstructive practices. :yes:
But you're right, a one-off would be worthwhile only if you considered it research for a more concerted attack on the local market. I mean, sheesh, $1500 bucks for what cost mebe $25 to manufacture and $75 to stock? You'd be putting $1K in your pocket by the time you made your 10th set...

imdying

13th August 2007, 15:57

But you're right, a one-off would be worthwhile only if you considered it research for a more concerted attack on the local market. I mean, sheesh, $1500 bucks for what cost mebe $25 to manufacture and $75 to stock? You'd be putting $1K in your pocket by the time you made your 10th set...If you're in manufacturing, you'll know why that is an unrealistic outcome that you've described. A disc is fairly useless without a centre and the mounting buttons for starters. $1500 would be close to the upper limit of a set of 3 OEM discs and pads. A single top of the line Brembo HP disc would cost approximately $800 here, complete with mounts and buttons.

marty

13th August 2007, 16:29

have you seen this place? are the RF900 brakes compatible with anything else?

http://stores.ebay.com/pacific-powersports_Brakes-Rotors-Calipers_W0QQfsubZ7091964QQfrsrcZ1

McJim

13th August 2007, 16:38

A single top of the line Brembo HP disc would cost approximately $800 here, complete with mounts and buttons.
:gob:

I'm gonna stick to engine braking only from now on.

imdying

13th August 2007, 16:45

:gob:

I'm gonna stick to engine braking only from now on.That's a top of the line race bike disc backed by a warranty and having been through rigorous testing. For a disc that you can use in those sort of circumstances with that degree of confidence in the reliability of the product, that's not bad money.

Skunk

13th August 2007, 16:50

I got a disc made to a one off pattern. I don't know what the material is (I left that to a trusted engineer friend).

Don't panic! It's on my bucket (AX100) and is a 300mm jobby. I expect it to warp...

Animal

13th August 2007, 17:19

Oh I'm an expert at getting around such obstructive practices. :yes:
But you're right, a one-off would be worthwhile only if you considered it research for a more concerted attack on the local market. I mean, sheesh, $1500 bucks for what cost mebe $25 to manufacture and $75 to stock? You'd be putting $1K in your pocket by the time you made your 10th set...

In my experience, $25 wouldn't cover the setup cost on a CNC mill, never mind the time to carve out the surplus material inside the disc blank, the button holes, the cross-drilling, the chamfered edges... Even if the blank was profiled through laser or water-jet, there is still a huge amount of finishing involved.

I must be doing something really wrong then, but the price to import the steel, the profile cutting, drilling and chamfering the holes and chamfering the contact surface circumference (on both sides), purchasing the buttons, and fitting the new discs to the original centres (using the buttons and a forming tool in a hydraulic press) made it completely unviable. I'd expect to make a huge investment in any prototype, and I am bloody tight with my costing, but I wouldn't anticipate seeing a profit for quite a long time. (This didn't even include my CAD time and programming my CNC mill.)

I'm probably missing a glaringly obvious point here, but how could you possibly do all that for $25? If your estimate is correct, then I'm sending ALL my manufacturing work to you from now on!

Ocean1

13th August 2007, 18:03

In my experience, $25 wouldn't cover the setup cost on a CNC mill, never mind the time to carve out the surplus material inside the disc blank, the button holes, the cross-drilling, the chamfered edges... Even if the blank was profiled through laser or water-jet, there is still a huge amount of finishing involved.

I must be doing something really wrong then, but the price to import the steel, the profile cutting, drilling and chamfering the holes and chamfering the contact surface circumference (on both sides), purchasing the buttons, and fitting the new discs to the original centres (using the buttons and a forming tool in a hydraulic press) made it completely unviable. I'd expect to make a huge investment in any prototype, and I am bloody tight with my costing, but I wouldn't anticipate seeing a profit for quite a long time. (This didn't even include my CAD time and programming my CNC mill.)

I'm probably missing a glaringly obvious point here, but how could you possibly do all that for $25? If your estimate is correct, then I'm sending ALL my manufacturing work to you from now on!

I wasn't suggesting you could make the complete assembly for $25, I was suggesting the OE supplier probably makes the bare disks for about that.

Hence the reference to the first being a lost-leader, pure R&D overhead.

riffer

13th August 2007, 19:32

have you seen this place? are the RF900 brakes compatible with anything else?

http://stores.ebay.com/pacific-powersports_Brakes-Rotors-Calipers_W0QQfsubZ7091964QQfrsrcZ1

Yup. The RF900 shares the same front rotors as the following Suzuki models:

GS 500 EK/EL/EM/EN/EP/ER/ES
GS 500 ET/EV/EW/EX/EY/K1-K3
GS 500 FK4/FK5/FK6/FK7
GSF1200 Bandit 1995-2000
GSF 250 N/ZM/P/NP/ZP/R/NR Bandit (GJ74A)
GS 500 EK/EL/EM/EN/EP/ER/ES (GM51A)
GS 500 ET/EV/EW/EX/EY/K1/K2/K3
GS 500 FK4/K4/FK5/K5/FK6/K6/FK7/K7
GS 1200 SSK1/ZK1 (GV78A)
GSX 1200 FSW/FSX

and rear rotors with:

GSX 600 FJ Katana
GSF 600 Bandit ST/SV/SW
GSX 600 FK/FL/FM/FN/FP/FR/FT Katana
RF 600 RR/RS/RT/RV
GSX 750 FK/FL/FM/FN/FP/FR/FS/FT/FV Katana
GSX-R 1100 G/H/J
GSX-R 750 RG/G/H
GS 500 EK/EL/EM/EN/EP/ER/ES
GS 500 ET/EV/EW/EX/EY/K1-K3
GS 500 FK4/FK5/FK6/FK7
GSF 1200 SV/SW/SX
GSF 1200 SK1-SK5/K1-K3 Bandit
GSX-R 600 WN/WP
GSX-R 750 J/K/L/M/N/WP
GSX-R 750 WR/WS
GSX-R 1100 K/L/M/N
GSX-R 1100 WP/WR/WS/WT/WV/WW

Mumbles

13th August 2007, 21:18

Brought brand new disks through AFC Motorcycles here is Palmerston for the ZXR 750
2 Front
1x Rear (cant remember the exact cost but worked out good <$1500. I think it worked out about $400 for each disk + Pads)
Metalgear do export direct to NZ so can order online if you like.
http://metalgear.com.au/

Liked the fact that I got my complete old disks back (no swaps)

Sorry not sure if your after options to purchase or just going over the manufacturing options.

pete376403

13th August 2007, 21:54

My friend bought a wrecked BMW k100 some years back. It needed new disks. One if HIS friends worked in the toolroom at Mitsubishi (nee Todd) Motors in Porirua, where they had all sorts of large and fancy metalworking machinery. Two landrover flywheels (cast iron) were cut, turned and ground down to become BMW disks and they worked VERY well, far better than the original stainless ones, even in the wet. Only problem, if you could call it that, was that the disks would get a very light surface rust coat overnight, which would wipe off on the first brake application. Just like original Ducati GT750 / 900s.

imdying

13th August 2007, 22:41

That was a cunning plan :yes:

Kickaha

13th August 2007, 22:50

Two landrover flywheels (cast iron) were cut, turned and ground down to become BMW disks and they worked VERY well, far better than the original stainless ones, even in the wet.

I did something similar with a BMW R75/7 I owned, but I used Hillman Hunter car discs and had a toolmaker machine them to suit

Animal

14th August 2007, 09:00

I wasn't suggesting you could make the complete assembly for $25, I was suggesting the OE supplier probably makes the bare disks for about that.

Hence the reference to the first being a lost-leader, pure R&D overhead.

Umm... gotcha. Jeez, I can be slow on the uptake sometimes!:Oops:

Animal

14th August 2007, 09:04

...they had all sorts of large and fancy metalworking machinery. Two landrover flywheels (cast iron) were cut, turned and ground down to become BMW disks and they worked VERY well, far better than the original stainless ones, even in the wet.

That's bloody clever! I like it!:yes:

Ocean1

14th August 2007, 10:26

Umm... gotcha. Jeez, I can be slow on the uptake sometimes!:Oops:

Me too. Hadn't noticed the relevance of your avatar. :niceone:

Solidworks?

Animal

14th August 2007, 10:45

Me too. Hadn't noticed the relevance of your avatar. :niceone:

Solidworks?

Thanks! It's long overdue for a replacement, but I like it.

It was done in Inventor. I don't have a Solidworks license, but I do a huge amount of onsite CAD work for clients that do use it. I have Inventor on my own computers. I don't have any particular preference between the two products. They both yield the result my clients need. Transfer to dxf is easy in both, and they both integrate well with both Fagor and Fanuc CNC architecture. The only thing that regularly does my head in is switching between the two... exasperatedly hunting for Inventor commands in Solidworks, and vice versa. :confused:

Ocean1

14th August 2007, 10:52

Thanks! It's long overdue for a replacement, but I like it.

It was done in Inventor. I don't have a Solidworks license, but I do a huge amount of onsite CAD work for clients that do use it. I have Inventor on my own computers. I don't have any particular preference between the two products. They both yield the result my clients need. Transfer to dxf is easy in both, and they both integrate well with both Fagor and Fanuc CNC architecture. The only thing that regularly does my head in is switching between the two... exasperatedly hunting for Inventor commands in Solidworks, and vice versa. :confused:

I can sympathise, I switch between Rhino, NS10 and Acad. A lot of the shortcuts I've built into Rhino for editing are used for view changes in NS11, much chaos until the brain re-wires for a new project.

Animal

14th August 2007, 12:27

I can sympathise, I switch between Rhino, NS10 and Acad. A lot of the shortcuts I've built into Rhino for editing are used for view changes in NS11, much chaos until the brain re-wires for a new project.

I'm keen to explore Rhino and once of my clients has hinted at providing me with a license. How do you find it in terms of CAM interfacing?

Ocean1

14th August 2007, 15:18

I'm keen to explore Rhino and once of my clients has hinted at providing me with a license. How do you find it in terms of CAM interfacing?

I don't own any CNC gear, I sub it all out so I don't have much experience with the various tweaks required by different gear. Most of the suppliers I use want straight dxf's, one or two like iges143, none of them have any problems with the flavours I send. In fact I get a little bit of translation work, someone gets sent say a Pro-E generated iges file but can't read/open it, so they send it to me and I stitch up all the nasty edges and deal with a few duplicate/bad entities and send it back.

Rhino has a few shortfalls but I can read most formats and save 'em as almost anything. First thing to get your head around is it's a modified surface modeling app, not a solids based one (although it does that. V4 is just out, bunch of new stuff I could have done with last year (of course). It's better supported via dedicated forums than anything else, and bloody cheap at about $2K. Novel demo version, it's fully functional, but you get 25 "saves" and no more. Have a play: http://download.mcneel.com/eval/?p=25

TLDV8

17th August 2007, 10:12

A single top of the line Brembo HP disc would cost approximately $800 here, complete with mounts and buttons.

One reason i watch Ebay and buy nearly everything out of the USA.

I had considered snapping these up to get the rotors and buttons so i could machine some carriers to suit the 2006 GSXR wheel.
That end price would have been under nz$300 to the door.

http://cgi.ebay.com/ebaymotors/Brembo-Brake-Disc-Rotors-Yamaha-YZF-320mm-Motorcycle_W0QQitemZ280141569378QQihZ018QQcategory Z35592QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

<img src= http://imagehost.vendio.com/bin/imageserver.x/00000000/dpero/08.YA31.32.jpg>

Anytime you want to see what part fits a model range,try http://www.ronayers.com/
There is a ..Where does this part fit.. search feature based off the part number...fwiw

I read once,excellent material for rotors was fire doors off steam locomotives after a ????? heat cycles.

imdying

17th August 2007, 10:54

Yeah, those are just regular rotors, not the HP ones. You saw that link on the zone for buttons out of Oz?

TLDV8

17th August 2007, 12:31

Yeah, those are just regular rotors, not the HP ones. You saw that link on the zone for buttons out of Oz?

What is a HP rotor,those ones in the Ebay link are the cast iron full floater's,cost here probably $1200/$1400 a pair.

Unless i missed something.
I saw the AU link,i would not buy anything off someone who takes a customers alloy frame and sets it down on the carpark tarmac to take pictures.
Would you buy a brake item off someone who shows that much disrespect ?
They should stick to show bikes that never see the road.
I would think a set of floater buttons would be little more than 7000 series alloy,done on a CNC with the usual backing shim and circlip.
They are nothing more than a tophat with a circlip groove.

imdying

17th August 2007, 13:04

Naw mate, followed the link, site way ghey (which I hate) so I closed the window. The Brembo HP range is their high end gear, here's a link to their gear on Yoyodyne http://www.yoyodyneti.com/Category.aspx?CategoryID=2989

On the ground?!?! But yep, floater buttons are little more than you describe, you could definitely knock a set up :yes:

Point is, even some of the best discs around are pretty cheap... you'd have to be in a pretty sticky situation before you'd go to the trouble of making your own.

TLDV8

17th August 2007, 13:29

The Brembo HP range is their high end gear, here's a link to their gear on Yoyodyne http://www.yoyodyneti.com/Category.aspx?CategoryID=2989

I think Vandriver posted a link to those on the Zone,is that material an improvement over cast iron.
It looks like cheap stainless :laugh: Maybe there was liability and wear issues with the cast iron longterm.
Brembo has been doing cast iron motorcycle rotors for around 36 years that i can think of. (roadbikes)

imdying

17th August 2007, 13:40

I would expect them to be stainless. I'm a fan of cast iron myself, it took them (manufacturers) years to figure out how to get better performance out of stainless discs compared to the old cast iron :lol:

http://www.brembo.com/ENG/HighPerformance-Brakes/MotoBrakes/HighPerformanceFloatingRotor.htm

Pancakes

17th August 2007, 14:26

so the bit that bolts on to the hub and the rotor have semi-circles that mate up and the buttons hold it all together? Just wanting to ask cos I know how it all works but not the nitty gritty. Do the hub bit and rotor press together and the buttons just stop side-to-side forces (not much in a straight setup) or do they take the whole load? Ho hard would it be to have a new hub bit made, get a stock rotor (or aftermarket rotor) and some buttons to get the party goin'? I ask cos I have scintered (sp?) pads and braided (legal) lines and don't want to go to twin disc because of cost and the std ones on my bike are heavy ish and while the faired model come out with twin discs they cost tons ($1000+ $'s) OEM for the parts and increase un-sprung weight. A larger diameter disc would be nice and the caliper locator for my bike is a flat plate so re-locating the caliper would be easy as.

imdying

17th August 2007, 14:50

Pancakes

17th August 2007, 16:47

Well they do take the whole load, but it's not quite like that if you know what I mean, because essentially there's nowhere for the disc to go, but yeah they do :) Side to side isn't too much of a problem, there's a pad either side pushing against it. You can definitely have a new centre made, and buttons, and have another rotor stuck on there, but serious dollars to have something made to a standard you'd trust your life with.

Don't worry about heavy, heavy is good... when you're talking about what amounts to a heatsink :yes: Put your money into good tyres, and replace them before they're totally toasted in the middle... best performance improvement you can make to nearly any bike :yes:

Who told you about my tyres? Hahahaha! Nah replaced the centre slic/commuter spec rear. If the disc is off say, a 600cc sports bike and the centre is the right material and the buttons are up to scratch, how hard would it be to design/mill the centre? Just same weight and larger diameter would be sweet. Mine has 300mm front discs, I guess there must be a few out there that would suit that are 320 or 340mm?