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VultureT140V
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| Joined: | Mon Feb 12th, 2007 |
| Location: | Norwich, United Kingdom |
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| Favourite Bike: | Kawasaki Z1300 Triumph T140V |
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Posted: Mon Oct 6th, 2008 07:18 pm |
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Hi there
I would like to know if it's possible to drill holes in my discs , i saw some discs that were drilled in a chevron pattern on a triumph bonneville at the weekend and i fancy some on my T140 cafe racer, is it something i can do on my milling machine or is it a specialist job?
Cheers Vulture
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Those who think they know everything only annoy those who do!
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drewpy
Member
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Posted: Mon Oct 6th, 2008 08:09 pm |
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I drilled mine with a pillar drill and a pattern off t'internet, then i very slightly chamfered them.
Its a dead boring (sic) job and I did 3 disks. can't say if they improved anything except they look cool.
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Delbert
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| Joined: | Thu Sep 4th, 2008 |
| Location: | Chippenham, United Kingdom |
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| Favourite Bike: | Yamaha RD400 |
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Posted: Mon Oct 6th, 2008 11:42 pm |
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I could set it up on a CNC mill/drill and do it in 15 minutes.
Actually it would take longer to set up than it would to drill.
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Greenbat
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Posted: Tue Oct 7th, 2008 01:02 pm |
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Go careful, or you'll start cracking the disc. Oddly enough I have just been given an assignment at college to design a sports c*r disc brake. I might see if that would stretch to a bike, and design it round my CB400/four.
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Frankfurt-Beesa
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| Joined: | Tue Jan 2nd, 2007 |
| Location: | Frankfurt Am Main, Germany |
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Posted: Tue Oct 7th, 2008 02:33 pm |
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Greenbat wrote: Go careful, or you'll start cracking the disc. Oddly enough I have just been given an assignment at college to design a sports c*r disc brake. I might see if that would stretch to a bike, and design it round my CB400/four.
Bike disc would be too skinny for a sports c*r, would buckle/crack first use, and sports c*r disc too fat for a bike (except maybe a harley which would benefit from some proper brakes) unless you came up with a disc wheel fitted in place of the spokes/web of a cast wheel, and then integrate the caliper in the fork so a single 12 pot caliper is cast in two parts integrated into the fork legs or ends(for upside down forks)..... interesting notion. Could use a single side swing arm type wheel and fit a single sports car disc with a huge 12 pot caliper, like off a Porsche inside he wheel. Wou8ld end up farking heavy though.
Problem will always be the cost/benefit calculation, two 'Normal' discs will always be cheaper than a really good sports c*r disc and they do wear out.
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Greenbat
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Posted: Tue Oct 7th, 2008 03:31 pm |
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Frankfurt-Beesa wrote: Greenbat wrote: Go careful, or you'll start cracking the disc. Oddly enough I have just been given an assignment at college to design a sports c*r disc brake. I might see if that would stretch to a bike, and design it round my CB400/four.
Bike disc would be too skinny for a sports c*r, would buckle/crack first use, and sports c*r disc too fat for a bike (except maybe a harley which would benefit from some proper brakes) unless you came up with a disc wheel fitted in place of the spokes/web of a cast wheel, and then integrate the caliper in the fork so a single 12 pot caliper is cast in two parts integrated into the fork legs or ends(for upside down forks)..... interesting notion. Could use a single side swing arm type wheel and fit a single sports car disc with a huge 12 pot caliper, like off a Porsche inside he wheel. Wou8ld end up farking heavy though.
Problem will always be the cost/benefit calculation, two 'Normal' discs will always be cheaper than a really good sports c*r disc and they do wear out.
I actually meant design a disc for a bike instead of a car. Designing one round my 400 would be nice and easy, since I can go out and measure the bike, instead of scouring the net for info on some exotic car I've never heard of. I'm not actually making it, just designing. On the other hand, the 400 brake is pretty awful. Pity he didn't specify designing a twin leading shoe brake for a small bike...
If you look up disc brakes on wikipedia, there is a load of interesting stuff about different disc designs. As I understand it, drilling holes in the disc lightens it, but adversely affects its performance.
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ClassicMCnut
Member
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Posted: Tue Oct 7th, 2008 03:58 pm |
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A disc for a D10 upwards bantam perhaps mate??? Might even be a market for them
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Hooli
Member
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Posted: Tue Oct 7th, 2008 05:45 pm |
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Greenbat wrote: but adversely affects its performance.
odd that, as its always sold as an upgrade. i thought the idea was to allow the gasses from the vapourising pads (& water on the disc) to escape rather than forming a cushion under the pad & holding it away from the disc.
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Greenbat
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Posted: Tue Oct 7th, 2008 07:35 pm |
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Hooli wrote: Greenbat wrote: but adversely affects its performance.
odd that, as its always sold as an upgrade. i thought the idea was to allow the gasses from the vapourising pads (& water on the disc) to escape rather than forming a cushion under the pad & holding it away from the disc.
Yes, if drilled on the bit of the disc that the pads actually clamp. Downside is it wears pads down quicker, and less mass means the disc has less capacity to absorb heat. It is written far better here: http://en.wikipedia.org/wiki/Disc_brake
As it says, the holes can be places where cracks develop, so I would be very wary of drilling a disc myself.
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Delbert
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| Joined: | Thu Sep 4th, 2008 |
| Location: | Chippenham, United Kingdom |
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Posted: Tue Oct 7th, 2008 09:26 pm |
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Greenbat wrote: so I would be very wary of drilling a disc myself.
Wots the differance with someone else doing it?
Have seen loads of disc's done when it became fashionable in the 70's - never heard of one cracking myself unless it is badly handled.
On the bike it would not be experiancing forces to start cracks
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drewpy
Member
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Posted: Tue Oct 7th, 2008 09:33 pm |
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found the site with drill patterns on
https://macshot.de/rd/brakediscs.html
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Hooli
Member
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Posted: Tue Oct 7th, 2008 10:04 pm |
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ive known of discs crack due to being drilled, including one on a trackday where the car suddenly spun out as one front brake suddenly wasnt a brake any longer.
from what i remember of that thread the holes need radiusing at the ends to help prevent cracks forming.
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drewpy
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Posted: Tue Oct 7th, 2008 10:05 pm |
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that's what I said at the beginning of this thread
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