Bicycle Braking Systems

roll Braking Systems Year 11 Engineering Studies Merewether High schoolhouse Nathan Dunshea 29/06/2012 Abstract In this report a compar great originator of collar Braking corpse of ru slight mensurate, debone and saucer entrust be do on a variety of beas including * * Effectiveness * Performance * Features * Materials * Frictional Components * Difference from same railroad car systems An Orthogonal and Pictorial drawing bequeath also be entrustd on a selected section of one of the braking systems being comp atomic number 18d. Introduction Bicycle Braking systems be a means of which we argon able to halt the movement of a wheel with the expulsion of kinetic nix.The Kinetic potential energy that is present in a moving bicycle is converted in to 3 diametrical forms of energy rut, sound and light. This is tire oute through the defense of a wheel to move when a halt applies a abrasional squeeze against the spinning movement of a wheel. Three different types of halt atomic number 18 gener aloney use on bicycles today the calliper, shell and criminal record systems. These triplet popular braking systems pitch their admit unique set of advantages and disadvantages that twist the population to purchase them. 2 caliper bracken draw Calliper stop Diagram 3 magnetic disc pasture brake Diagram 3 book Brake Diagram 4 Drum Brake Diagram 4 Drum Brake Diagram Procedure I used the Internet to research pictures, binds and suppliers of Braking systems in put up to access the appropriate culture needed for this report. Results Effectiveness, Performance, Features Comparison Effectiveness 10 Cross-Section of a bicycle raise pasture brake 10 Cross-Section of a bicycle jampack brake The effectiveness of these Braking systems will be a measure of their business leader to execute over a period of time.It is necessary for these brake not to only perform tumesce once, moreover over umteen instances, including moments of seriou sly excessive braking. In todays modern bicycle, m twain things will affect the braking systems ability to be effective. The weather, go and tear over many uses, as thoroughly as the type of braking taking place roll in the hay all go for unfavourable effects on brake system. Drum brake system are not the closely popular style of brake for a bicycle. This could be accredited to their effectiveness over time compared to both measure halt and disc stop. Drum halt are typically genuinely heavy, complicated to perform upkeep on and are lots egress to brake fading.Break fading apprize be defined as the injury of braking force able to be exerted by the braking system at any point, and this oftentimes happens due to overheating as a result of unvarying hard braking. Drum brake are unable to dissipate heat anywhere near as efficiently as disc brakes as the frictional forces that turn kinetic energy into heat are all enclosed at bottom the devise itself, which is ofte n housed at the hub of the wheel. In fact, many companies defy been forced to put warning labels on their hubs to contrive sure children arent unaware of the heat generated, and subsequently burn themselves.This makes them especially susceptible to brake fading, roundthing that both phonograph record and caliper brakes dont rich person a great problem with. In adverse weather conditions, the gravel brake can show of its unique summation both the disc and mensurate brake does not work. The Drum brake is fully enclosed, and therefore is not affected by rain, mud and early(a) substances that may impede the frictional force exerted on the wheel. 12 phonograph record brake to be fitted to a tummy Bike 12 phonograph record brake to be fitted to a Mountain Bike Disc Brakes are precise popular on Mountain Bikes, which require blockheaded wheels and are often subject to grim terrain.Because the disc brake is mount to the hub, a certain clearance from the ground is maintained at all times, generally keeping mud from obstructing the pads and disc. If water is to get stuck to a embarrasseder place a disc brakes pad, there are generally holes through which it can quickly escape so to not compromise the friction produced in the system. Touring bikes have been cognise to prefer disc brakes to types of calliper brakes, as the foresightful journeys and significant use of brakes would not wear out the rim as they do using a calliper brakes system.The typical Disc Brake system is a truly adaptable structure as it can perform better than Calliper Brakes in the mud, rain and snow as the coefficient of friction isnt as at risk of contaminants disturbing the system. Disc brakes are also less(prenominal) prone to brake fading when subject to long periods of braking pressure, as they are very good at cooling put through compared to tog up and calliper brakes. A disk brake is also less likely to cause a popped tyre, with the heat not being clean directly into t he tyre as in calliper brakes. 14 Shimano Bicycle Caliper Brake 14 Shimano Bicycle Caliper BrakeCalliper Brakes are generally the most vernacular of the braking system for the eitherday bicycle. Excluding the original founding quality of the equipment and significants, calliper brakes are often affected in general by the moisture that is on the rim, as that will significantly interrupt the ability to stop. Tyre thickness can also pose a problem to the calliper braking system, as the arms will be under greater flexion, thus lessening brake effectiveness. However, the Calliper brake system is effective on the average road bike and is the simplest and easiest to perform maintenance on of all trey conceptions.This system also has a very bigger mechanical advantage, meaning very little trial has to be put in by the rider in order to properly apply the brakes. Calliper brakes are also by far the ligh tribulation and least expensive, making them popular among non-competitive rid ers, with most road bikes sedate come fitted with this system. Performance The performance of a braking system is based on the raw fish fillet queen and ability for one item-by-item use. This comparison will be based purely on stop billet and performance, disregarding things much(prenominal) as * Weight of system * Weather/Terrain Brake Fading * Heat Dissipation The Disc Brake is said to have the grea evidence fillet power, and therefore permits least stopping distance, of all terzetto systems. This means they are often fitted to competitive riders bikes, because they are often tone dyinging a higher speed and therefore need the greater stopping power that the disc brake provides compared to that of the drum and calliper braking system. In a report By Guy Kesteven for UK organisation What Mountain Bike, a variety of disc brakes were tried and true from many different manufacturers to tribulation the power of each system.The try was performed as follows All the brake s were tested with a 180mm rotor and a 50Nm force on the jimmy (1N is the sum of cash of force required to accelerate 1kg at 1m/s2), with the stock pads. To fully posterior in the rotors and pads, the brakes were given 60 one-second pulls at 15km/h, followed by 30 devil-second pulls at 20km/h. After a 30-second cooling-down period, the testing began. With the wheel spinning at 30km/h, each brake was applied for three seconds and then left to get for 10 seconds. This cycle was repeated 15 times. The results were then averaged out to provide a single power rating. Guy Kesteven What Mountain Bike. After the test had been completed, the Formula R0 disc braking system had the sterling(prenominal) power of all 33 separate tested. It was found to have a power of 124 Nm when stopping, which is capable to 12. 645 kilogram-force meters. Calliper Brakes have one of the best designs in basis of their Mechanical Advantage. Very little effort has to be put in by the user to have the bra kes perform as well as possible. Disc Brakes have an overall stopping power advantage over the general calliper brake, however some versions of the calliper brake have a greater stopping power than the drum brake design.With the huge variety of designs in the field of Calliper Brakes, stopping power can range from quite poor to very high. An workout of this stopping power is the test carried out by Matt Pacocha in the June 2009 edition of Velo raws. A group of Bicycle Calliper brakes were to be tested to measure their stopping power This test was performed on a flat, windless road. For each brake, the rider accelerated to 40km/hr then grabbed the brakes hard on a pre-determined mark and recorded stopping distance.This test was performed 10 times for each brake, and the stopping distances were averaged. Matt Pacocha Velonews. At the end of the test, the Shimano 7900 dual pivot calliper brake was found to have the greatest braking force, with the shortest stopping distance of 7. 18 metres. It was also found that the average slowness of the bicycle was 8. 59 m/s2, whilst the greatest deceleration was recorded at 10. 35 m/s2 (Over 1 G-force). Drum Brakes are less powerful than the disc brake, and therefore have a greater stopping distance in normal, controlled conditions.Compared to Calliper brakes it is not clear-cut which has a better stopping distance, as there are many different versions of each type of brake to choose from. However, it is said that the modern drum brake is able to provide a much smoother, more authorized deceleration than the majority of calliper brake systems. Features Each of these braking systems have their own features which help to enhance the ability to stop the movement of a bicycle. Whilst some of these advantages are purely performance based, others may have features that are cost-efficient or maintenance friendly.One of the most fundamental features in the success of the disc brake is its ability to dissipate the heat genera ted from the frictional forces. Disc brakes are out in the open air with a macroscopic surface area, meaning the cooling process happens more quickly and efficiently. another(prenominal) important, yet perhaps underestimated feature of the disc brake is its positioning. Disc brakes are well away from the tyres and ground, thus creating distance amid the braking system and mud, dirt and other potential environmental interferences.Drum brakes however, are certainly the best in resisting those environmental factors. As the braking mechanism itself is housed within a shell of sorts, no amount of weather can have an adverse effect on the ability of the drum brake to perform its task. Once encloseed, drum brake system is also very low maintenance, and often doesnt have to be managed again until a new wheel is needed. condescension this, Drum Brakes can be a hassle if maintenance must occur, as they can be thorny to access because of the shell it is housed in. Calliper Brakes are gen erally the cheapest of the three designs available.As they are often mounted to the bicycle at one single point, accessing the brake pads and cables is made much easier than the other systems. Another feature that is multipurpose on the majority of road bikes with calliper brake systems is the quick relieve mechanism. This feature is designed as to loosen the brake system exuberant so the wheel can be removed without having to mess roughly with loosening brake cables as well. Materials used for construction and frictional components Brake Pads are perhaps the most important part of both the Disc and Calliper braking systems.The brake pad is generally made from a carrefour that possesses a moderately high coefficient of friction, but also depends on the materials ability to absorb and dissipate the heat produced in the process of braking. If these criteria can be met without having a negative impact on overall braking performance, an appropriate material has been found. In years gone by, an asbestos based immix was the most common material from which brake pads would be made, however because of the toxic nature of asbestos that coif no longer allowed. The modern bicycle Brake Pad is enerally made from arctic compound. The rims on bicycles directly affect the performance of the Calliper braking Systems. whatever bike rims today are made from an aluminium alloy, which provide a coefficient of friction when in tactual sensation with the rubber heterogeneous of the brake pads of nearly 0. 4. Other materials, such as various Carbon poises, have lately become more popular as they are light and aerodynamic. However, they do not provide a very good frictional force between the everyday brake pad, and so other materials are often prefer by the everyday cyclist.Calliper brake systems also have brake cables that transfer the motion actuated by the rider from the brake lever to the braking system itself. These brake cables are made from thin wire trade name that has been braided together to improve its tensile strength and ability to perform. The Disc in the saucer brake system is an integral part of the bicycles stopping power. The Brake pad (rubber composite) must have a high plentiful coefficient of friction when applied to the disc to halt movement with damaging the surface.To provide this, the disc is made from alloy, with stainless steel being popular among spile bikes. A brake drum has an outer shell in which the braking system itself is contained. This outer shell is subject to weathering from the outside and heat from within. With this in mid, cast-iron is generally the material chosen as it can cope with these two burdens other materials could falter under. The shoes of the Drum brake are the parts that push outwards to produce the frictional forces needed in the brake design.These brake shoes are generally made when two pieces of saddlery steel are welded together. After they are welded together, the frictional materia l known as brake lining is connected on to the sheet steel with either adhesive resin or other means such as a rivet. It is also important to remember that the rubber composite of bicycle tyres also has frictional forces acting from the material it is rolling on. For instance, if a cyclist was riding along a concrete surface, the coefficient of friction would be 0. 8, much higher than that of rubber or brake lining to metal (0. ). Thankfully, the relatively light weight of the human body compared to the force exerted by our mechanical braking systems allows us to still move along these surfaces. (FF = ? RN) How they differ from comparable car systems On most bicycles, the braking systems installed will often be very simplistic and just there to do the job. Most will have the same type of brake on both attend and approve wheel, with the braking of the bike mostly relying on human action with levers and cables, as well as the mechanical advantage some of these designs provide.Howe ver, when upgrading these systems to work on a much heavier vehicle such as a car, many things can change. It is not uncommon to have different types of brakes on the former and back set of wheels, and hydraulics become a very important part of stopping your car. In todays modern designs, at least one set Disk Brakes are fitted to just about every car on the road. Disk Brakes are the most effective type of braking system that we could fit to our cars, however, it is still common for the front brakes to be disk, but the rear to be drum brakes.Drum brakes can be used as the lay brake, and by suitable them to the rear of the car, companies can save money by not having to install another braking system. The Disc Brake in a car is obviously in a much bigger scale than that of a bicycle. Despite this, the two systems are very similar in the basic design concept. Strength of this part however, must be much greater when installed in an Automobile. Winnard & Sons Ltd, a company base d in the UK that deals with commercial vehicle braking components, has a guideline to the tensile strength on the brake contact surfaces of their products. Guideline tensile strength on test pieces machined from brake drum/disc contact faces 241 N/mm2 European Requirement minimum 35,000 psi Amercian Requirement minimum Winnard & Sons Ltd Brake Disc and Brake Drum Material Specification The materials used in the brake pads of both the disk and calliper brakes are different when they are made for cars. When gimpy the momentum of a car, the brake pad is put under a much greater force than when stopping a bicycle. This is due to a number of things, including the speed at which the car is travelling and the mass of the vehicle, both of which are generally higher in cars.The metals used are normally steel, copper or brass fibres, as well as a mixture of many different composites including graphite, iron oxide, glass fibres, phosphate and rubber that are bonded together with a res in of phenol formaldehyde. The metals that are added help to increase life span by improving the ability of the compound to dissipate heat at high speeds. The complexity of all three designs is greatly heightened when moving from bicycle to motor vehicle. One aspect of move Vehicle braking that creates extra pressure is the hydraulic action of the brakes.Hydraulics rely on brake fluid, typically containing ethylene glycol, to transfer pressure from the controlling unit of measurement to the brake mechanism. In a motor vehicle, drum brakes often serve a specific purpose that they would be useless for when installed on a bicycle the park brake. As I stated earlier, these Drum brakes are fitted to the rear wheels and can save companies significant amounts of money by not having to install a completely separate parking brake. As this asset of an emergency brake is vital to a larger system, not only are they more common in cars, but they must also be bigger and exert a greater force.T hese three types of braking systems hold the same principles when applied to a greater surface vehicle in a motor car, however many things must change to accommodate these increased forces. Conclusion Each of these three braking systems are often used by a specific type of bicycle with a specific need. An example of this is Disc brakes being preferred by those who ride either Mountain or Touring bikes. As shown by the two field tests referenced in this report, completed by Velonews and What Mountain Bike, both Calliper brakes and disc brakes both have a very big potential to have immense stopping power.But to have that stopping power, the proper materials with appropriate frictional forces would have had to been in place. At the absolute top of the line models, every little percentage point is considered, i. e. * * Weight * Frictional Forces * Materials * Angle * Type of System It was also discovered that as we transition from bicycle to car braking systems, many things must be altered. Although the basic engineering principles are often the same, there are many variables that are altered to improve to braking systems to cope with the extra forces exerted by a motor vehicle.For example, the change in materials of brake pads to accommodate the much more intense levels of heat being produced when heavy braking is taking place. I consider this report reveals that the braking system you own can make a big difference on effectiveness and performance. The features, materials used and frictional forces in act can all be positive or negative depending on the type of riding taking place. Recommendations I recommend selecting one of these three types of braking systems based on what their use in the long run will be.If you plan to use the bike for competitive purposes when increased stopping power is necessary, I would suggest purchasing a Disc brake system. However, if the bike is simply for leisure, perhaps the more cost effective Calliper Brake system would bett er suit. If you are planning to ride in muddy areas where the possibility of substances interfering with the frictional forces throughout the braking system, the fully enclosed drum brake system could be the appropriate option. However, if you wish to simply have the greatest overall stopping power, I would recommend a Disk Brake system be installed. The most mportant thing to remember is that every situation is unique, and to do research in order to attain the conciliate brake for your needs. Bibliography * http//www. edmunds. com/car-technology/brakes-drum-vs-disc. hypertext markup language * http//www. bikewebsite. com/bicycle-bra. htm * http//www. jaxquickfit. com. au/brakes * http//www. exploratorium. edu/cycle/brakes2. hypertext mark-up language * http//bikeadvice. in/drum-brakes/ * http//www. sheldonbrown. com/gloss_dr-z. hypertext mark-up languagedrum * http//www. livestrong. com/article/340500-adjust-bicycles-drum-brakes/ * http//www. skyshop. com. au/LANDING. pdf * http //www. razyguyonabike. com/doc/page/? page_id=8174 * http//sheldonbrown. com/calipers. html * http//www. bicyclestore. com. au/parts/brakes/calliper-brakes. html * http//www. 123helpme. com/view. asp? id=57299 * http//www. bike-riding-guide. com/bicycle-brakes. html * http//eecycleworks. com/VNJune%20BrakeTest. pdf * http//auto. howstuffworks. com/auto-parts/brakes/brake-parts/brake-calipers2. htm * http//urbanvelo. org/torker-graduate-commuter-bike-review/ * http//www. cycle-systems-academy. co. uk/index. php/topics/brakes/brakes-theory/mechanics-of-brakes/mechanics-of-the-system? tart=5 * http//www. physicsforums. com/showthread. php? t=158582 * http//www. longjohn. org/bremsen/bremsen_en. html * http//www. abcarticledirectory. com/Article/Bicycle-Brakes-Guide/786406 * http//www. cdxetextbook. com/brakes/brake/disc/brakefrictionmat. html * http//www. bikeforums. net/archive/index. php/t-302000. html * http//www. alibaba. com/salesroom/aluminum-bike-rim. html * http//cars. about. c om/od/thingsyouneedtoknow/a/discvsdrum. htm * http//www. fezzari. com/ frequent/rb_brakes * http//bicycletutor. com/sidepull-caliper-brakes/ * http//www. icycling. com/bikes-gear/bikes-and-gear-features/big-squeeze-road-disc-brakes * http//www. unitconversion. org/moment-of-force/newton-meters-to-kilogram-force-meters-conversion. html * http//www. bikeradar. com/mtb/gear/ class/components/disc-brake-systems/product/review-formula-ro-12-46051 * http//www. winnard. co. uk/downloads/twcbd1_material_specification_2011. pdf * http//www. autoshop101. com/forms/brake03. pdf * http//www. pbr. com. au/technical/documents/hydraulicbrakesystemsguide. pdf * http//www. tcbbrakesystems. com/hdopenroad-text. html * http//www. sae. rg/events/bce/presentations/2009/okamura. pdf Appendix Braking Power test Matt Pacocha, Velonews June 2009 Braking Power test Matt Pacocha, Velonews June 2009 What Mountain Bike UK Calliper Brake Power Testing &8212&8212&8212&8212&8212&8212&8212&8212&8212&8212&8212&821 2&8212&8212 1 . http//www. edmunds. com/car-technology/brakes-drum-vs-disc. html 2 . http//www. bikewebsite. com/bicycle-bra. htm 3 . http//www. jaxquickfit. com. au/brakes 4 . http//www. jaxquickfit. com. au/brakes 5 . http//www. exploratorium. edu/cycling/brakes2. html 6 . http//bikeadvice. in/drum-brakes/ 7 . http//www. heldonbrown. com/gloss_dr-z. htmldrum 8 . http//www. livestrong. com/article/340500-adjust-bicycles-drum-brakes/ 9 . http//www. exploratorium. edu/cycling/brakes2. html 10 . http//sheldonbrown. com/sturmey-archer_3-spd. html 11 . http//www. skyshop. com. au/LANDING. pdf 12 . http//www. mountainbikestoday. com/mountain-bike-resources/should-my-mountain-bike-have-disc-brakes 13 . http//www. crazyguyonabike. com/doc/page/? page_id=8174 14 . http//sheldonbrown. com/calipers. html 15 . http//www. bicyclestore. com. au/parts/brakes/calliper-brakes. html 16 . ttp//www. fezzari. com/support/rb_brakes 17 . http//www. 123helpme. com/view. asp? id=57299 18 . http//www. bike-riding-guide. com/bicycle-brakes. html 19 . http//www. bikeradar. com/mtb/fitness/article/how-we-test-hydraulic-disc-brakes-24345/ 20 . http//www. unitconversion. org/moment-of-force/newton-meters-to-kilogram-force-meters-conversion. html 21 . http//www. cycle-systems-academy. co. uk/index. php/topics/brakes/brakes-theory/mechanics-of-brakes/mechanics-of-the-system? start=5 22 . http//eecycleworks. com/VNJune%20BrakeTest. pdf 23 . http//eecycleworks. om/VNJune%20BrakeTest. pdf 24 . http//auto. howstuffworks. com/auto-parts/brakes/brake-parts/brake-calipers2. htm 25 . http//urbanvelo. org/torker-graduate-commuter-bike-review/ 26 . http//www. physicsforums. com/showthread. php? t=158582 27 . http//www. longjohn. org/bremsen/bremsen_en. html 28 . http//www. tcbbrakesystems. com/hdopenroad-text. html 29 . http//www. abcarticledirectory. com/Article/Bicycle-Brakes-Guide/786406 30 . http//bicycletutor. com/sidepull-caliper-brakes/ 31 . http//www. cdxetextboo k. com/brakes/brake/disc/brakefrictionmat. html 32 . ttp//www. alibaba. com/showroom/aluminum-bike-rim. html 33 . Paul L. Copeland, Engineering Studies The Definitive guide 34 . http//www. bicycling. com/bikes-gear/bikes-and-gear-features/big-squeeze-road-disc-brakes 35 . http//www. bicycling. com/bikes-gear/bikes-and-gear-features/big-squeeze-road-disc-brakes 36 . http//www. autoshop101. com/forms/brake03. pdf 37 . Paul L. Copeland, Engineering Studies The Definitive guide 38 . Paul L. Copeland, Engineering Studies The Definitive guide 39 . http//cars. about. com/od/thingsyouneedtoknow/a/discvsdrum. htm 40 .