Bicycle and motorcycle geometry
Bicycle and motorcycle geometry is the collection of key measurements that define a particular bike configuration. Primary among these are wheelbase, steering axis angle, fork offset, trail; these parameters have a major influence on. Wheelbase is the horizontal distance between the centers of rear wheels. Wheelbase is a function of rear frame length, steering axis angle, fork offset, it is similar to the term wheelbase used for trains. Wheelbase has a major influence on the longitudinal stability of a bike, along with the height of the center of mass of the combined bike and rider. Short bikes are much more suitable for performing stoppies; the steering axis angle called caster angle or head angle, is the angle that the steering axis makes with the horizontal or vertical, depending on convention. The steering axis is the axis; the steering axis angle matches the angle of the head tube. In bicycles, the steering axis angle is measured from the horizontal. For example, Lemond offers: a 2007 Filmore, designed for the track, with a head angle that varies from 72.5° to 74° depending on frame size a 2006 Tete de Course, designed for road racing, with a head angle that varies from 71.25° to 74°, depending on frame size.
Due to front fork suspension, modern mountain bikes - as opposed to road bikes - tend to have slacker head tube angles around 70° although they can be as low as 62°. At least one manufacturer, Cane Creek, offers an after-market threadless headset that enables changing the head angle. In motorcycles, the steering axis angle is called the rake angle or just rake and is measured from the vertical. For example, Moto Guzzi offers: a 2007 Breva V 1100 with a rake of 25°30’ a 2007 Nevada Classic 750 with a rake of 27.5° The fork offset is the perpendicular distance from the steering axis to the center of the front wheel. In bicycles, fork offset is called fork rake. Road racing bicycle forks have an offset of 40–50 mm; the offset may be implemented by curving the forks, adding a perpendicular tab at their lower ends, offseting the fork blade sockets of the fork crown ahead of the steerer, or by mounting the forks into the crown at an angle to the steer tube. The development of forks with curves is attributed to George Singer.
In motorcycles with telescopic fork tubes, fork offset can be implemented by either an offset in the triple tree, adding a triple tree rake to the fork tubes as they mount into the triple tree, or a combination of the two. Other, less-common motorcycle forks, such as trailing link or leading link forks, can implement offset by the length of link arms; the length of a fork is measured parallel to the steer tube from the lower fork crown bearing to the axle center. Trail, or caster, is the horizontal distance from where the front wheel touches the ground to where the steering axis intersects the ground; the measurement is considered positive if the front wheel ground contact point is behind the steering axis intersection with the ground. Most bikes have positive trail, though a few, such as the two-mass-skate bicycle and the Python Lowracer have negative trail. Trail is cited as an important determinant of bicycle handling characteristics, is sometimes listed in bicycle manufacturers' geometry data, although Wilson and Papodopoulos argue that mechanical trail may be a more important and informative variable, although they both describe nearly the same thing.
Trail is a function of steering axis angle, fork offset, wheel size. Their relationship can be described by this formula: Trail bicycle = R w cos − O f sin and Trail motorcycle = R w sin − O f cos where R w is wheel radius, A h is the bicycle head angle measured from the horizontal, A r is the motorcycle rake angle measured from the vertical, O f is the fork offset. Trail can be increased by increasing the wheel size, decreasing or slackening the head angle, or decreasing the fork offset. Trail decreases as head angle increases, as wheel diameter decreases. Motorcyclists tend to speak of trail in relation to rake angle; the larger the rake angle the larger the trail. Note that, on a bicycle, as rake angle increases, head angle decreases. Trail can vary as the bike steers. In the case of traditional geometry, trail decreases as the bike leans and steers in the direction of
A trail is a path, track or unpaved lane or road. In the United Kingdom and the Republic of Ireland path or footpath is the preferred term for a walking trail; the term is applied, in North America, to routes along rivers, sometimes to highways. In the US, the term was used for a route into or through wild territory used by emigrants. In the USA "trace" is a synonym for trail, as in Natchez Trace; some trails are single use and can only be used for walking, horse riding and cross-country skiing. There are unpaved trails used by dirt bikes and other off-road vehicles and in some places, like the Alps, trails are used for moving cattle and other livestock. In Australia, the term track can be used interchangeably with trail, can refer to anything from a dirt road to an unpaved pedestrian path. In New Zealand, the terms track or walkway are used exclusively except in reference to cross-country skiing: "walkways vary enormously in nature, from short urban strolls, to moderate coastal locations, to challenging tramps in the high country ".
Walkway is used in St. John's, Canada, where the "Grand Concourse", is an integrated walkway system. In the United Kingdom, the term trail is in common usage. Longer distance walking routes, government-promoted long distance paths, collectively known as National Trails, are frequently called ways; the term footpath is preferred for pedestrian routes, including long distance trails, is used for urban paths and sometimes in place of pavement. Track is used for wider paths used for hiking; the terms bridleway, restricted byway are all recognised legal terms and to a greater or lesser extent in general usage. The increased popularity of mountain biking has led to a proliferation of mountain bike trails in many countries; these will be grouped to form larger complexes, known as trail centers. In the early years of the 20th century, the term auto trail was used for a marked highway route, trail is now used to designate routes, including highway routes, designated for tourist interest like the Cabot Trail, Nova Scotia and the Quilt Trails in the US.
The term trail has been used by developers and urban planners for a variety of modern paved roads and boulevards, in these countries, some highways continue to be called a trail, such as the Susquehanna Trail in Pennsylvania, a designation that varies from a two-lane road to a four-lane freeway. A unusual use of the term is in the Canadian province of Alberta, which has multi-lane freeways called trails. Trail segregation, the practice of designating certain trails as having a specific preferred or exclusive use, is common and diverse. For example, bike trails are used not only on roads open to motor vehicles, but in trail systems open to other trail users; some trails are segregated for use by both equestrians and mountain bikes, or by equestrians only, or by mountain bikes only. Designated "wilderness area" trails may be segregated for non-wheeled use. Trail segregation for a particular use is accompanied by prohibitions against that use on other trails within the trail system. Trail segregation may be supported by signage, trail design and construction, by separation between parallel treads.
Separation may be achieved by "natural" barriers including distance, banking and vegetation, by "artificial" barriers including fencing and walls. Bicycle trails encompass a wide variety of trail types, including shared-use paths used for commuting, off-road cross country trails and downhill mountain bike trails; the number of off-road cycle trails has increased along with the popularity of mountain bikes. Off-road bicycle trails are function-specific and most waymarked along their route, they may form part of larger complexes, known as trail centres. Off-road trails incorporate a mix of challenging terrain, smooth fireroads, paved paths. Trails with an easy or moderate technical complexity are deemed cross-country trails, while trails difficult to experienced riders are more dubbed all-mountain, freeride, or downhill. Downhilling is popular at ski resorts such as Mammoth Mountain in California or Whistler Blackcomb in British Columbia, where ski lifts are used to get bikes and riders to the top of the mountain.
EuroVelo bicycle routes are a network of long-distance cycling routes criss-crossing Europe in various stages of completion, more than 45,000 km was in place by 2013. It is envisaged that the network will be complete by 2020 and when finished, the EuroVelo network's total length will exceed 70,000 km. EuroVelo is a project of the European Cyclists' Federation. EuroVelo routes can be used for bicycle touring across the continent, as well as by local people making short journeys; the routes are made of both existing national bike routes, such as the Dutch LF-Routes, the German D-Routes, the British National Cycle Network, existing general purpose roads, together with new stretches of cycle routes to connect them. Off-road cycling can cause soil erosion and habitat destruction if not carried out on established trails; this is so when trails are wet, overall though, cycling may have only as mu
The rail profile is the cross sectional shape of a railway rail, perpendicular to its length. Early rails were made of cast iron or wrought iron. All modern rails are hot rolled steel with a cross section approximate to an I-beam, but asymmetric about a horizontal axis; the head is profiled to resist wear and to give a good ride, the foot profiled to suit the fixing system. Unlike some other uses of iron and steel, railway rails are subject to high stresses and are made of high quality steel, it took many decades to improve the quality of the materials, including the change from iron to steel. Minor flaws in the steel that may pose no problems in other applications can lead to broken rails and dangerous derailments when used on railway tracks. By and large, the heavier the rails and the rest of the trackwork, the heavier and faster the trains these tracks can carry. Rails represent a substantial fraction of the cost of a railway line. Only a small number of rail sizes are made by steelworks at one time, so a railway must choose the nearest suitable size.
Worn, heavy rail from a mainline is reclaimed and downgraded for re-use on a branchline, siding or yard. The weight of a rail per length is an important factor in determining rails strength and hence axleloads and speeds. Weights are measured in kilograms per metre; as a kilogram is 2.2 lb and a metre is 1.1 yards, the pounds-per-yard figure is exactly double the kilograms-per-metre figure. In rail terminology pound is a contraction of the expression pounds per yard and hence a 132–pound rail means a rail of 132 pounds per yard. Rails are made in a large number of different sizes; some common European rail sizes include: In the countries of former USSR 65 kg/m rails and 75 kg/m rails are common. Thermally hardened 75 kg/m rails have been used on heavy-duty railroads like Baikal–Amur Mainline, but have proven themselves deficient in operation and were rejected in favor of 65 kg/m rails; the American Society of Civil Engineers specified rail profiles in 1893 for 5-pound-per-yard increments from 40 to 100 lb/yd.
Height of rail equaled width of foot for each ASCE tee-rail weight. ASCE 90 lb/yd profile was adequate. In 1909, the American Railway Association specified standard profiles for 10 increments from 60 to 100 lb/yd; the American Railway Engineering Association specified standard profiles for 100 lb/yd, 110 lb/yd and 120 lb/yd rails in 1919, for 130 lb/yd and 140 lb/yd rails in 1920, for 150 lb/yd rails in 1924. The trend was to strengthen the web. Disadvantages of the narrower foot were overcome through use of tie plates. AREA recommendations reduced the relative weight of rail head down to 36%, while alternative profiles reduced head weight to 33% in heavier weight rails. Attention was focused on improved fillet radii to reduce stress concentration at the web junction with the head. AREA recommended the ARA 90 lb/yd profile. Old ASCE rails of lighter weight remained in use, satisfied the limited demand for light rail for a few decades. AREA merged into the American Railway Engineering and Maintenance-of-Way Association in 1997.
By the mid-20th century, most rail production was heavy. Sizes under 100 lb/yd rail are for lighter duty freight, low use trackage, or light rail. Track using 100 to 120 lb/yd rail is for lower speed freight branch rapid transit. Main line track is built with 130 lb/yd rail or heavier; some common North American rail sizes include: Some common North American crane rail sizes include: Some common Australian rail sizes include: 50 kg/m and 60 kg/m are the current standard, although some other sizes are still manufactured. Some American sizes are used on northwest Western Australian iron ore railways. Early rails were used on horse drawn wagonways with wooden rails, but from the 1760s using strap-iron rails, which consisted of thin strips of cast iron fixed onto wooden rails; these rails were too fragile to carry heavy loads, but because the initial construction cost was less, this method was sometimes used to build an inexpensive rail line. Strap rails sometimes separated from the wooden base and speared into the floor of the carriages above, creating what was referred to as a "snake head".
However, the long-term expense involved in frequent maintenance outweighed any savings. These were superseded by cast iron rails that were with the wagon wheels flat. An early proponent of this design was Benjamin Outram, his partner William Jessop preferred the use of "edge rails" in 1789 where the wheels were flanged and, over time, it was realised that this combination worked better. The earliest of these in general use were the so-called cast iron fishbelly rails from their shape. Rails made from cast iron broke easily, they could only be made in short lengths. John Birkinshaw's 1820 patent, as
A gun carriage is a frame and mount that supports the gun barrel of an artillery piece, allowing it to be manoeuvred and fired. The earliest guns were laid directly onto the ground, with earth being piled up under the muzzle end of the barrel to increase the elevation; as the size of guns increased, they began to be attached to heavy wooden frames or beds that were held down by stakes. These began to be replaced by wheeled carriages in the early 16th century. From the 16th to the mid-19th century, the main form of artillery remained the smoothbore cannon. By this time, the trunnion had been developed, with the result that the barrel could be held in two recesses in the carriage and secured with an iron band, the "capsquare"; this simplified elevation, achieved by raising or lowering the breech of the gun by means of a wedge called a quoin or by a steel screw. During this time, the design of gun carriages evolved only with the trend being towards lighter carriages carrying barrels that were able to throw a heavier projectile.
There were two main categories of gun carriages: These were designed for use aboard a ship or within a fortification and consisted of two large wooden slabs called "cheeks" held apart by bracing pieces called "transoms". The trunnions of the gun barrel sat on the top of the cheeks; because these guns were not required to travel about, they were only provided with four small wheels called "trucks", whose main function was to roll backwards with the recoil of the gun and allow it to be moved forward into a firing position after reloading. Traversing the gun was achieved by levering the rear of the carriage sideways with handspikes. An improvement on this arrangement started at the end of the 18th century with the introduction of the traversing carriage in fortifications but on ships as well; this consisted of a stout wooden beam. The beam was fitted to a pivot at the centre, to one or more trucks or "racers" at the front; this allowed the gun to be swung in an arc over a parapet. Alternatively, the pivot could be fitted to the front of the beam and the racers at the rear, allowing the gun to fire through an embrasure.
The traversing beam sloped upwards towards the rear, allowing the gun and its carriage to recoil up the slope. These were designed to allow guns to be deployed on the battlefield and were provided with a pair of large wheels similar to those used on carts or wagons; the cheeks of field carriages were much narrower than those on the naval carriage and the rear end, called a "trail", rested on the ground. When the gun needed to be moved any distance, the trail could be lifted onto a second separate axle called a limber, which could be towed by a team of horses or oxen. Limbers had been invented in France in about 1550. An innovation from the mid-18th century was the invention of the "block trail", which replaced the heavy cheeks and transoms of the "double-bracket" carriage with a single wooden spar reinforced with iron; the First World War is considered the dawn of modern artillery because, like repeating firearms, the majority of barrels were rifled, the projectiles were conical, the guns were breech loaded and many used fixed ammunition or separate loading charges and projectiles.
Some of the features of modern carriages are listed below and illustrated in the photo gallery: Box trail - A box trail is a type of field carriage, rectangular in shape and consists of a ladder frame with decking. The goal was stability. Box trail carriages on howitzers had an open area near the breech to permit the high angles of fire necessary for indirect fire. On larger guns, there was a ramp to hold ready rounds to make reloading easier. A problem with a box trail carriage is that it limits easy access to the breech, so the barrel needs to be lowered to load and raised for each shot which reduces the rate of fire. At the end of WW I box trail carriages became less common. Ease of loading and rate of fire were improved by providing better access to the breech. Pole trail - A pole trail was sometimes used with early horse-drawn light artillery; the single trail resembled a pipe and was meant to be strong, easy to maneuver and easy to work around. After the First World War, pole trails became less common because light horse-drawn artillery was in decline.
Some guns received new carriages to increase traverse, elevation and to make them suitable for motor traction. Split trail - A split trail carriage has two trails which can be spread to provide greater stability. However, another reason for this design is to provide greater angles of traverse. Since the carriage is stationary and elevation are controlled by separate hand wheels. Another advantage of a split trail is easier access to the breech for reloading at different angles. Many guns produced. Outriggers - Since the First World War many anti-aircraft guns have had collapsible two and four outrigger carriages with leveling jacks to provide stability, high-angle fire, 360° traverse; the three outrigger carriages tend to have two detachable wheels for transport, while four-outrigger carriages have four. The four-outrigger versions are referred to as cruciform carriages because when their outriggers are deployed they form a cross. Gun shields - Not all modern guns have shields. Before World War I, shields were intended to provide gun crews with protection at shorter ranges from the recently
Trail, British Columbia
Trail is a city in the West Kootenay region of the Interior of British Columbia, Canada. It was named after the Dewdney Trail. Trail has an area of 34.78 square kilometres. The city is located on both banks of the Columbia River 10 km north of the United States border; this section of the Columbia River valley is located between the Monashee Mountains to the west and the Selkirk Mountains to the east. The Columbia flows directly north-south from Castlegar, turns east near downtown Trail, meets the Canada–United States border at Waneta and the Pend d'Oreille River. Summer climate in Trail is hot and dry with moderately cool nights. Temperatures exceed 35 °C during summer afternoons, average 29 °C. Thunderstorms are common during the late-Spring and Summer season moving into the valley from the south; the fall months bring dense river fog overnight and in the morning, as a cold air inversion lingers above the warm river surface. Winters are mild to cold with periods of moderate snowfall. Nearby villages such as Warfield and Fruitvale receive greater amounts of snow due to higher elevation.
The Monashee Mountains are the first major mountain range east of the Coastal Mountains to intercept moisture laden westerly flow from the Pacific Ocean. As a result, areas west of Trail, including the Christina Range, Rossland Range, the city of Rossland, the Blueberry-Paulson section of the Crowsnest Highway receive greater amounts of winter precipitation in the form of heavy snow. Vegetation in the Trail area, although lush, is noticeably drier than other areas with a more westerly aspect. According to Statistics Canada, Trail's population was 7,709 during the Canada 2016 Census; the city is noted for its large Italian community. There are 1,320 people in Trail with Italian ancestry. Trail is the location of the head office of the Kootenay Boundary Regional District, one of the city's employers. Trail is part of School District 20 Kootenay-Columbia and schools in the town include: Glenmerry Elementary School J. Lloyd Crowe Secondary School James L Webster Elementary School St. Micheals Catholic School Kootenay-Columbia Learning Centre The school district in the Greater Trail area is focused on improving the district and schools and has a focused, well organized improvement plans in place.
The strategies selected to achieve the goals are a blend of research, best practice, innovative thinking. The district has implemented numerous strategies to support schools in improving student learning. Most schools have comprehensive and research-based strategies to meet the goals. In 2007, the J. Lloyd Crowe Secondary School Replacement program started the construction of a new facility in Trail to replace the existing school, built in the late 1950s; the new facility opened in September 2009. Trail’s statistics differ from that of the province in the percentage of the population aged 45–64 with a trades certificate or diploma: Trail—26%, compared to BC—14%; this is directly attributable to Teck Resources and the diversified mining and metals company's presence in the area. The percentage of this age group with a university level education is very different: Trail—12%, compared to BC—22%; the general picture is a working population geared to the trades and very reliant on Teck Cominco for employment.
Employing 1,800 people, Teck Resources is the region’s largest employer. The average age of an employee at Teck Resources' Trail operation is 47, it is anticipated that within 15 years Teck Resources' Trail operation will have a new and different labour force. A younger and more technical labour force will most replace those that are retiring; the big picture for the area is one of an aging population which brings about ongoing employment opportunities in the area. This is evidence based on the improved housing sales in the years between 2005 and 2007, making the Greater Trail area a target destination for people looking for better quality of life in a smaller community setting; the City of Trail is home to the largest hospital in the West Kootenay region. In 1927, a smelter in Trail was polluting, via smoke deposition, farmlands south of the border in the United States; the US agreed to bring the issue before the International Joint Commission. A 1931 report the IJC recommended Canada compensate the United States for a sum of $350,000 to the farmers, the US rejected the offer.
In 1935 the two countries agreed to arbitration, in which Canada again offered to compensate the US $350,000 for all damages caused before 1932. In April 1938, after extensive expert assessments, the tribunal acknowledged that the smelter had caused damage after 1932. In 1941, it held that "no State has the right to use or permit the use of its territory in such a manner as to cause injury by fumes in or to the territory of another or the properties or persons therein, when the case is of serious consequence and the injury is establish by clear and convincing evidence." This case, known as the "Trail smelter arbitration", is a landmark in environmental law, as it helped to establish the "polluter pays" principle for transnational pollution issues. As its contribution to the Manhattan Project's P-9 Project, Cominco built and operated a 1000 to 1200 pound per month electrolytic heavy water plant at Trail, which operated from 1943 to 1956. Lt-Col Nichols noted environmental damage from emissions to the "beautiful valley and mountain slopes"
Trail is a census-designated place and unincorporated community in Jackson County, United States. As of the 2010 census it had a population of 702, it has a post office with a ZIP code of 97541. Trail lies at the intersection of Oregon Route 227 and Oregon Route 62, just north of Shady Cove and west of Lost Creek Lake, a reservoir of the Rogue River. Trail is located around the mouth of Trail Creek at the Rogue River; this region experiences warm and dry summers, with no average monthly temperatures above 71.6 °F. According to the Köppen Climate Classification system, Trail has a warm-summer Mediterranean climate, abbreviated "Csb" on climate maps
An animal track is an imprint left behind in soil, snow, or mud, or on some other ground surface, by an animal walking across it. Animal tracks are used by hunters in tracking their prey and by naturalists to identify animals living in a given area. Books are used to identify animal tracks, which may look different based on the weight of the particular animal and the type of strata in which they are made. Tracks can be fossilized over millions of years, it is for this reason we are able to see fossilized dinosaur tracks in some types of rock formations. These types of fossils are called trace fossils since they are a trace of an animal left behind rather than the animal itself. In paleontology, tracks preserve as sandstone infill, forming a natural mold of the track. Flukeprint, the track of a whale on the surface of the ocean Footprint Pugmark Spoor Animal Tracks Animal Tracks Animal Tracks NatureTracking.com Animal Tracks Website Bear-Tracker Animal Tracks Website Tracker Certifications in North America Tracker Certifications in Africa