brussel Posted November 10, 2009 Share slowbee simple answer is the amount of leverage. Basically a ratio of the disk diameter vs wheel diameter...if you do the maths, a 200mm disk gives about 25% more stopping power. Also a larger surface to increase heat dissipation. Link to comment Share on other sites More sharing options...
obree Posted November 10, 2009 Share The further away from the hub you move the lower the torque, but higher the speed. So you need more force to stop a smaller disc than a bigger one. But the bigger one is going faster. Look at a wheel magnet, does the same revolutions if it is placed at the hub or at the nipple. Link to comment Share on other sites More sharing options...
levett Posted November 10, 2009 Share I have no idea why some disks are not meant for sintered pads. If you have such a disk handy' date=' please test it with a magnet and tell us what you find. It may lead to the answer. [/quote'] I think 'resin only' discs are made of 'normal' Steel and then chromed. Link to comment Share on other sites More sharing options...
patches Posted November 10, 2009 Share ok, so here's what I found out... I think the IS 6 hole standard has a BCD of 44mm based on this info, and used M5x0.8x10 bolts. http://www.ioffer.com/i/HBC-Ti-Disc-Rotor-185mm-ISO-44mm-BCD-98043399 And I read that thickness varies from 1.5mm to 2.5mm. So 1.6mm ASTM A 304L Stainless Steel sheeting would probably be pretty good to use?! (It's a common thickness). As for the laser cutting, our engineering firm uses Plasma Cut in Germiston. But I think they are only cost effective if the order quantity is large. And finally... The CAD drawing... well... this basic 203mm rotor took me less than 5min in Autodesk Inventor, which with certain interfaces can translate direct onto the CNC cutter. Plus if one really wants they can apply a "braking force" to see if the rotor design is prone to warp. (5 min didn't allow me to do that). But as you can imagine, with a little more time, one can produce some really good looking designs So if anyone wants to experiment with custom rotors, I'll be more than happy to do the CAD work! patches2009-11-10 11:42:49 Link to comment Share on other sites More sharing options...
Procrates Posted November 10, 2009 Share Go have a look here guyswww.dirtydogmtb.com/2006preview.htmwww.dirtydogmtb.com/who is willing to club in? $250 free shipping. Link to comment Share on other sites More sharing options...
greatwhite Posted November 13, 2009 Share ok' date=' so here's what I found out... I think the IS 6 hole standard has a BCD of 44mm based on this info, and used M5x0.8x10 bolts.http://www.ioffer.com/i/HBC-Ti-Disc-Rotor-185mm-ISO-44mm-BCD-98043399And I read that thickness varies from 1.5mm to 2.5mm. So 1.6mm ASTM A 304L Stainless Steel sheeting would probably be pretty good to use?! (It's a common thickness).As for the laser cutting, our engineering firm uses Plasma Cut in Germiston. But I think they are only cost effective if the order quantity is large.And finally... The CAD drawing... well... this basic 203mm rotor took me less than 5min in Autodesk Inventor, which with certain interfaces can translate direct onto the CNC cutter. Plus if one really wants they can apply a "braking force" to see if the rotor design is prone to warp. (5 min didn't allow me to do that). But as you can imagine, with a little more time, one can produce some really good looking designs So if anyone wants to experiment with custom rotors, I'll be more than happy to do the CAD work![/quote'] Nice model Patches - suggest you use 304 not 304L - cheaper and typically stronger - bruched finish might be nice too,. Also add a radius to the sharp corner you have at the end of each arm in the centre. Can you do FEA on that? Link to comment Share on other sites More sharing options...
AndreZA Posted November 13, 2009 Share ok' date=' so here's what I found out... I think the IS 6 hole standard has a BCD of 44mm based on this info, and used M5x0.8x10 bolts.http://www.ioffer.com/i/HBC-Ti-Disc-Rotor-185mm-ISO-44mm-BCD-98043399And I read that thickness varies from 1.5mm to 2.5mm. So 1.6mm ASTM A 304L Stainless Steel sheeting would probably be pretty good to use?! (It's a common thickness).As for the laser cutting, our engineering firm uses Plasma Cut in Germiston. But I think they are only cost effective if the order quantity is large.And finally... The CAD drawing... well... this basic 203mm rotor took me less than 5min in Autodesk Inventor, which with certain interfaces can translate direct onto the CNC cutter. Plus if one really wants they can apply a "braking force" to see if the rotor design is prone to warp. (5 min didn't allow me to do that). But as you can imagine, with a little more time, one can produce some really good looking designs So if anyone wants to experiment with custom rotors, I'll be more than happy to do the CAD work! [/quote'] patches, I would really like to take this further. Imagine a disc with a bunch of "XT" on the braking serface or if you are willing to pay you can have a slogan or even your name. Link to comment Share on other sites More sharing options...
dalem44 Posted November 16, 2009 Share Are there any patents regarding the discs? Link to comment Share on other sites More sharing options...
greatwhite Posted November 16, 2009 Share Are there any patents regarding the discs? Hmmmm - doubt it - ISO std You might have hassles with shimano C/Lock Link to comment Share on other sites More sharing options...
AndreZA Posted November 16, 2009 Share GW, I think dalem is talking about designs. I think if you do not copy something to the tee and then sell it it should be fine. Link to comment Share on other sites More sharing options...
GoLefty!! Posted November 16, 2009 Share Hmm, Most disc brake rotors I've come across are magnetic i.e. a magnetic is attracted to it which means it cannont be austentic stainless stainless such as 304 or 18/0, 18/8 or 18/10.It has to be Martensitic Stainless steel, well at least the higher quality rotors should be.Martensitic stainless steel contains chromium, molybdenum, nickel and higher carbon content to make it more machinable and also heatreatable. It's highly likely htat both grades are used and create different price points for rotors. If we look at some brands , one of which is a family of the Crocodile,those rotors are half the price of OEM rotors but do exhibit more flex than OEM rotors.this could be due to the material. Actuallynow that I think of it, my OEM rotors are magentic and the el cheapo's are far less so.. Rotors can be cut from many different materials. The much maligned titanium is also used here but CP ti is best avoided. the harder highly oxygenated alloys are better as well as the american 3v, 2.5AL and 6V 4Al alloys. I once toyed with phenolic resin reinforces fibre rotors. Way to grabby and were excellent for practicing somersaults Link to comment Share on other sites More sharing options...
AndreZA Posted November 16, 2009 Share I would pay good money if someone can make me a set of these. Link to comment Share on other sites More sharing options...
dalem44 Posted February 22, 2010 Share Is anyone going to try make these? Link to comment Share on other sites More sharing options...
greatwhite Posted February 23, 2010 Share I would pay good money if someone can make me a set of these. Nice looking discs, but structrually unsound - the open section at the end of the T (in XT) could be a problem - at the very least, you need to run these anti clockwise as viewing the top left view Link to comment Share on other sites More sharing options...
AndreZA Posted February 23, 2010 Share Nice looking discs' date=' but structrually unsound - the open section at the end of the T (in XT) could be a problem - at the very least, you need to run these anti clockwise as viewing the top left view[/quote'] it has already been virtually tested and found to be 100% safe. Just waiting for final numbers. Link to comment Share on other sites More sharing options...
Dirtbreath Posted February 23, 2010 Share And what happens when you upgrade to XTR? Link to comment Share on other sites More sharing options...
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