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techtalk:ref:wheels12 [2023/10/28 15:24] hippysmack [REF: Wheels, Brakes & Tires] |
techtalk:ref:wheels12 [2024/01/25 04:15] (current) hippysmack |
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| ===== Calculating M/C to Caliper Ratio ===== | ===== Calculating M/C to Caliper Ratio ===== | ||
| - | * First get the area of the master cylinder pistons. The area of a circle is the amount of space the circle covers. ((cjburr of the XLFORUM http://xlforum.net/forums/showthread.php?t=44210)) | + | * First get the area of the master cylinder pistons. The area of a circle is the amount of space the circle covers. ((cjburr of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-drivetrain/sportster-motorcycle-tires-wheels-and-brakes-aa/26692-what-size-master-cylinder-for-multi-pistons?t=44210)) |
| * The formula for calculating the area of a circle is A = πr² where pi (π) equals 3.14 and the radius (r) is half the diameter. | * The formula for calculating the area of a circle is A = πr² where pi (π) equals 3.14 and the radius (r) is half the diameter. | ||
| * Or 3.14 x (r x r) = piston area (for one piston). | * Or 3.14 x (r x r) = piston area (for one piston). | ||
| - | * The pressure is arrived at by Pascals law. ((cjburr of the XLFORUM http://xlforum.net/forums/showthread.php?t=44210)) | + | * The pressure is arrived at by Pascals law. ((cjburr of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-drivetrain/sportster-motorcycle-tires-wheels-and-brakes-aa/26692-what-size-master-cylinder-for-multi-pistons?t=44210)) |
| * F (force) = P (pressure) X A (area) or P (pressure) = F (force) ÷ A (area). | * F (force) = P (pressure) X A (area) or P (pressure) = F (force) ÷ A (area). | ||
| * So with a 10 lbs force at the 5/8" break lever, we get P = 10 ÷ 0.306640625 where P = 32.6 PSI. \\ You would then multiply 32.6 by the area of the piston in the brake caliper to find the actual pressure applied to the disc by each brake piston. | * So with a 10 lbs force at the 5/8" break lever, we get P = 10 ÷ 0.306640625 where P = 32.6 PSI. \\ You would then multiply 32.6 by the area of the piston in the brake caliper to find the actual pressure applied to the disc by each brake piston. | ||
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| ===== Master Cylinder to Wheel Cylinder Ratio ===== | ===== Master Cylinder to Wheel Cylinder Ratio ===== | ||
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| Conversions: \\ | Conversions: \\ | ||
| * 7/16" = 11.1125mm | * 7/16" = 11.1125mm | ||
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| * 1-7/8" = 47.6mm | * 1-7/8" = 47.6mm | ||
| - | * General rule of thumb when swapping master cylinders is: ((XLdaveR of the XLFORUM http://xlforum.net/forums/showthread.php?t=786022)) | + | * General rule of thumb when swapping master cylinders is: ((XLdaveR of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-drivetrain/sportster-motorcycle-tires-wheels-and-brakes-aa/94666-question-about-master-cylinders?t=786022)) |
| * Bigger M/C = More pressure required to compress brake lever, less lever travel. \\ The MoCo reduced pressure at the caliper in dual discs systems with a larger master cylinder piston. | * Bigger M/C = More pressure required to compress brake lever, less lever travel. \\ The MoCo reduced pressure at the caliper in dual discs systems with a larger master cylinder piston. | ||
| * Smaller M/C = Less pressure required, more lever travel. \\ If the area of the master cylinder piston is reduced, the pressure at the caliper increases. \\ A smaller master cylinder piston used in a dual disc system would make it too easy to lock up the brakes and make for an unsafe system. | * Smaller M/C = Less pressure required, more lever travel. \\ If the area of the master cylinder piston is reduced, the pressure at the caliper increases. \\ A smaller master cylinder piston used in a dual disc system would make it too easy to lock up the brakes and make for an unsafe system. | ||
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| \\ | \\ | ||
| - | From sml1226 of the XLFORUM ((http://xlforum.net/forums/showthread.php?t=1990492&highlight=master+ratio)) \\ | + | From sml1226 of the XLFORUM ((https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-drivetrain/sportster-motorcycle-tires-wheels-and-brakes-aa/186079-calculating-for-new-brakes?t=1990492&highlight=master+ratio)) \\ |
| <blockquote>The ratio charts don't exactly tell you precisely what you need, but it does provide what you need to match your master cylinder to your calipers. \\ | <blockquote>The ratio charts don't exactly tell you precisely what you need, but it does provide what you need to match your master cylinder to your calipers. \\ | ||
| It does NOT tell you the effect on stopping power, and it doesn't consider your rotor, wheel diameter or bike's weight, all of which affect braking. \\ | It does NOT tell you the effect on stopping power, and it doesn't consider your rotor, wheel diameter or bike's weight, all of which affect braking. \\ | ||
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| ===== Got the Caliper But What Size Master Cylinder to Use? ===== | ===== Got the Caliper But What Size Master Cylinder to Use? ===== | ||
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| There will be a range of master cylinder diameters which will work for a given set of brake pistons. \\ | There will be a range of master cylinder diameters which will work for a given set of brake pistons. \\ | ||
| A small master piston will be light to pull on, but will feel spongy and may not give full braking before the lever hits the bars. \\ | A small master piston will be light to pull on, but will feel spongy and may not give full braking before the lever hits the bars. \\ | ||
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| And following the chart, you can see that even if you went to a 3/4" (app 19mm) bore master instead, the ratio is still (24.11:1). \\ | And following the chart, you can see that even if you went to a 3/4" (app 19mm) bore master instead, the ratio is still (24.11:1). \\ | ||
| But you'll have less lever travel. It's always a tradeoff. \\ | But you'll have less lever travel. It's always a tradeoff. \\ | ||
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| ===== Master Cylinder to Wheel Cylinder Ratio Chart ===== | ===== Master Cylinder to Wheel Cylinder Ratio Chart ===== | ||
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| Example for the table below; \\ | Example for the table below; \\ | ||
| Area of a 10mm bore M/C = 78.54 mm² (3.14 x r² (5 x 5, or 25mm) = 78.54). \\ | Area of a 10mm bore M/C = 78.54 mm² (3.14 x r² (5 x 5, or 25mm) = 78.54). \\ | ||
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| * [[techtalk:ref:wheels12b|VROD Brembo Caliper Install on 2007 883L]] | * [[techtalk:ref:wheels12b|VROD Brembo Caliper Install on 2007 883L]] | ||
| * [[techtalk:ref:wheels12c|XR1200 brakes on a 2007 1200R]] | * [[techtalk:ref:wheels12c|XR1200 brakes on a 2007 1200R]] | ||
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| ====== Brembo Calipers ====== | ====== Brembo Calipers ====== | ||
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| ===== 4 Piston Brembo ===== | ===== 4 Piston Brembo ===== | ||
| ==== Rebuilding ==== | ==== Rebuilding ==== | ||
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| No one should be afraid of rebuilding a brake caliper. They are one of the most simple components you will find on a motorcycle. \\ | No one should be afraid of rebuilding a brake caliper. They are one of the most simple components you will find on a motorcycle. \\ | ||
| Two halves, a few pistons and a variety of O-rings. Simply order a rebuild kit for your caliper and buy some fresh brake fluid. \\ | Two halves, a few pistons and a variety of O-rings. Simply order a rebuild kit for your caliper and buy some fresh brake fluid. \\ | ||
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| If you don’t already have one go buy a service manual for your bike. They are invaluable. \\ | If you don’t already have one go buy a service manual for your bike. They are invaluable. \\ | ||
| - | {{:techtalk:ref:wheels:vrod_brembo_front_caliper_rebuild_1_by_bassboy311.jpg?direct&300|}} ((photo by bassboy311 of the XLFORUM http://xlforum.net/forums/showthread.php?t=1127805)) {{:techtalk:ref:wheels:vrod_brembo_front_caliper_rebuild_2_by_bassboy311.jpg?direct&250|}} ((photo by bassboy311 of the XLFORUM http://xlforum.net/forums/showthread.php?t=1127805)) {{:techtalk:ref:wheels:vrod_brembo_front_caliper_rebuild_3_by_bassboy311.jpg?direct&300|}} ((photo by bassboy311 of the XLFORUM http://xlforum.net/forums/showthread.php?t=1127805)) \\ | + | {{:techtalk:ref:wheels:vrod_brembo_front_caliper_rebuild_1_by_bassboy311.jpg?direct&300|}} ((photo by bassboy311 of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-drivetrain/sportster-motorcycle-tires-wheels-and-brakes-aa/117093-how-to-rebuild-a-brake-caliper?t=1127805)) {{:techtalk:ref:wheels:vrod_brembo_front_caliper_rebuild_2_by_bassboy311.jpg?direct&250|}} ((photo by bassboy311 of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-drivetrain/sportster-motorcycle-tires-wheels-and-brakes-aa/117093-how-to-rebuild-a-brake-caliper?t=1127805)) {{:techtalk:ref:wheels:vrod_brembo_front_caliper_rebuild_3_by_bassboy311.jpg?direct&300|}} ((photo by bassboy311 of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-drivetrain/sportster-motorcycle-tires-wheels-and-brakes-aa/117093-how-to-rebuild-a-brake-caliper?t=1127805)) \\ |
| ====== GMA Calipers ====== | ====== GMA Calipers ====== | ||
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| * **Not recommended for use with imported stainless steel rotors**. | * **Not recommended for use with imported stainless steel rotors**. | ||
| - | |GMA 4-pot calipers on a 1977 XLH ((photo by BLIGHT of the XLFORUM http://xlforum.net/forums/showthread.php?t=667563&page=3))|GMA 4-pot calipers on a 1978 XLH ((photos by ericfreeman of the XLFORUM http://xlforum.net/forums/showthread.php?t=667563&page=3)) \\ Custom brake lines & angled banjo adapter to make bleeding the calipers easier.|| | + | |GMA 4-pot calipers on a 1977 XLH ((photo by BLIGHT of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/86228-gimme-a-break-er-some-brakes/page3?t=667563&page=3))|GMA 4-pot calipers on a 1978 XLH ((photos by ericfreeman of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/86228-gimme-a-break-er-some-brakes/page3?t=667563&page=3)) \\ Custom brake lines & angled banjo adapter to make bleeding the calipers easier.|| |
| |{{:techtalk:ref:wheels:1977_xlh_w_gma_caliper_by_blight.jpg?direct&300|}}|{{:techtalk:ref:wheels:1978_xlh_w_gma_caliper_pic1_by_ericfreeman.jpg?direct&300|}}| {{:techtalk:ref:wheels:1978_xlh_w_gma_caliper_pic2_by_ericfreeman.jpg?direct&300|}}| | |{{:techtalk:ref:wheels:1977_xlh_w_gma_caliper_by_blight.jpg?direct&300|}}|{{:techtalk:ref:wheels:1978_xlh_w_gma_caliper_pic1_by_ericfreeman.jpg?direct&300|}}| {{:techtalk:ref:wheels:1978_xlh_w_gma_caliper_pic2_by_ericfreeman.jpg?direct&300|}}| | ||
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| * Pad Volume (in³): 0.63 | * Pad Volume (in³): 0.63 | ||
| - | * Galfer pads: ((bplinson of the XLFORUM http://xlforum.net/forums/showthread.php?t=73101)) | + | * Galfer pads: ((bplinson of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-drivetrain/sportster-motorcycle-tires-wheels-and-brakes-aa/37011-wilwood-caliper-replacement-pad-part-s?t=73101)) |
| * FD068G1054 = Organic | * FD068G1054 = Organic | ||
| * FD068G1375 = Sintered | * FD068G1375 = Sintered | ||
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| Galfer (800) 685-6633 \\ | Galfer (800) 685-6633 \\ | ||
| Caliper Bolt Torque (per Wilwood): 22 ft-lbs \\ | Caliper Bolt Torque (per Wilwood): 22 ft-lbs \\ | ||
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| ====== Experiences from XLFORUM Members ====== | ====== Experiences from XLFORUM Members ====== | ||
| - | + | From Randy_rots: ((https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-drivetrain/sportster-motorcycle-tires-wheels-and-brakes-aa/169230-master-cylinder-size-w-4-piston-caliper?t=1815643)) \\ | |
| - | From Randy_rots: ((http://xlforum.net/forums/showthread.php?t=1815643)) \\ | + | |
| What counts the most is the summary size of all the pistons. I was messing up with various calipers and master cylinders. \\ | What counts the most is the summary size of all the pistons. I was messing up with various calipers and master cylinders. \\ | ||
| Here's what I found: \\ | Here's what I found: \\ | ||
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| - XL 14mm MC and 2000-2003 4 pot single caliper (not tested yet but I belive it will feel better than with 9/16" MC since it's little smalled I.D.) | - XL 14mm MC and 2000-2003 4 pot single caliper (not tested yet but I belive it will feel better than with 9/16" MC since it's little smalled I.D.) | ||
| - XL 1/2" MC and Brembo 4 pot single caliper (32mm piston size) - not tested yet but I believe it will be the best way to go | - XL 1/2" MC and Brembo 4 pot single caliper (32mm piston size) - not tested yet but I believe it will be the best way to go | ||
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