Title of Invention: LOAD-MINIMIZING, TROLLEY ARRESTER APPARATUS AND METHOD Abstract: A system comprising a cable held in suspension and a trolley traveling along the cable relies on a brake to control velocity and net downhill acceleration of the trolley. The trolley may include a brake pad positioned to contact the cable. At the downhill end of the ride, the lever actuating the brake is caught and lifted by a capture ring, thus relieving the braking load on the trolley. Also, the trolley engages a comparatively modest, second resistance mechanism, such as, for example, a system of springs, that gradually increases in resistance with distance of motion of the trolley thereagainst, bringing the trolley to a gradual halt. Detailed Description: RELATED APPLICATIONS This application is a continuation of co-pending U.S. patent application Ser. No. 12/233,270, filed Sep. 18, 2008, entitled LOAD-MINIMIZING, TROLLEY ARRESTER APPARATUS AND METHOD, and is a continuation-in-part of U.S. Pat. No. 7,637,213, issued Dec. 29, 2009, entitled UNIVERSAL BRAKE ASSEMBLY, which is a continuation-in-part of U.S. patent application Ser. No. 11/168,101, filed Jun. 28, 2005, now abandoned, and are hereby incorporated by reference. BACKGROUND 1. The Field of the Invention This invention relates to suspended cable systems and, more particularly, to novel systems and methods for braking and retrieving trolleys traveling on suspended cable systems. 2. The Background Art Weather conditions such as temperature and wetness affect the performance of typical trolleys configured to slide or roll along suspended cables. For example, rain on a cable may significantly change the coefficient of friction between a trolley brake and the cable. Accordingly, a trolley brake that is acceptable for dry conditions, may be unacceptable for wet conditions. Thus, operators must closely monitor weather conditions when using current trolleys. What is needed is a trolley brake providing acceptable performance across a greater range of weather conditions. Many trolley systems, sometimes called Ziplines, provide no braking. They simply use a cable declining at a shallow angle in which a rise at the lower end slows a user. Others may have a brake set at a fixed parameter. Also, current trolleys do not provide a user control “on-the-fly” over the magnitude of a braking force or friction force generated by the trolley as it travels along a cable. That is, to one degree or another, a user or knowledgeable operator must preselect the braking force or the range of braking force to be provided by the trolley. Once selected, the arrangement is not easily or safely changed without stopping the trolley and relieving the trolley of the user's weight. In certain embodiments, legal liability and user inexperience may favor such inflexibility. However, in other embodiments, greater user control may be desirable. Accordingly, what is needed is a trolley providing safe, “on-the-fly” adjustment between minimum braking and maximum braking. Furthermore, when using a trolley as the basis for an amusement ride, revenue may largely depend on the number operators employed to operate the ride and throughputs the number of users served within a given period of time. Currently, to a large degree, safety concerns dictate the numbers for both. For example, one of the potential hazards of an amusement ride employing a trolley is the possibility of collision. A first rider may ride a first trolley to some location along a cable. Assuming that the first rider has reached the bottom and exited the ride, a second rider may ride a second trolley down the same cable. Accordingly, if the first rider did not actually reach the lower end due to over-braking, serious injury may occur when the second rider collides with the first rider. What is needed is a trolley retrieval system configured to maximize user throughput, minimize operator interaction, and reduce or eliminate the risk of collision. BRIEF SUMMARY OF THE INVENTION In view of the foregoing, in accordance with the invention as embodied and broadly described herein, a method and apparatus are disclosed in one embodiment of the present invention as including a trolley comprising a frame, a brake assembly, and a sheave mount. In selected embodiments, a brake assembly in accordance with the present invention may provide significant adjustability. For example, a brake assembly may include a brake pad that may be removed and replaced, should wear so dictate. Additionally, a brake pad may itself be readily adjustable to provide a desired or customized braking effect to suit conditions. Various material properties and characteristics may be considered when selecting a material for a brake pad in accordance with the present invention. Often a material that has certain advantageous characteristics may have others that are disadvantageous. For example, one material may have excellent wear resistance, but its coefficient of friction against a cable may vary greatly depending on whether the cable is dry. Accordingly, the material may be suitable for dry conditions, yet be hazardous for wet conditions. In certain embodiments, it may be advantageous to provide a brake pad having repeatable and consistent performance with respect to wear, coefficient of friction, or the like regardless of temperature, wetness, etc. To provide the advantages of a brake pad in accordance with the present invention, a brake pad may be formed of various segments, typically positioned in series. So positioned, the width of each segment may control the contact area between each segment and the cable. The contact area may vary between segments. For example, in certain embodiments, one segment may have a width greater than the width of another segment. Accordingly, the former segment may provide a greater contribution to the overall performance of the brake pad than the latter segment. By controlling the composition of the segments, the contact area of the segments, and the gaps between the segments, the performance of a brake pad may be optimized to a given trolley application. For example, in selected embodiments, it may be desirable for a brake pad in accordance with the present invention to slide along a cable. That is, the brake pad may reduce the speed of the trolley along the cable 12, but not overly slow or stop it. Accordingly, in one embodiment, certain segments may be formed of a first, substantially inelastic material (e.g., high density polyethylene (HDPE), ultra high molecular weight (UHMW) polyethylene, or the like). The rest of the segments may be formed a second, elastic material (e.g., multi-rubber or elastomeric materials such as are used for the caliper brake pads of a bicycle). Elastomers may strip water from a surface, but typically do not wear as well as other polymers. Accordingly, overall, the brake pad may have both acceptable wear and frictional engagement even when applied to a wet cable. By adjusting the number of segments corresponding to the first and second materials and the contact areas associated with those segments, a proper balance of characteristics may be achieved. In selected embodiments, a trolley in accordance with the present invention may provide a user (e.g. operator, or rider in some circumstances) “on-the-fly” control over the magnitude of a braking force generated by the trolley as it travels along a cable. For example, by adjusting the moment arm (e.g. leverage) at which the weight of a user is applied to the frame of a trolley, the magnitude of the resulting moment may be controlled. The magnitude of the moment may then dictate the magnitude of the normal force against the cable generating the frictional braking force. Accordingly, by adjusting the moment arm at which the weight of a user is applied to the frame of a trolley, a user may control, within a particular range, the speed of the trolley for a particular catenary, or naturally hanging cable. In selected embodiments, a trolley may include a carriage configured to secure to, operate with, and be adjusted with respect to a frame or portion of a frame throughout a range of motion bounded by a first position of the carriage and a second position of the carriage with respect to the frame. A carriage may move along the frame through the range of motion without compromising the connection between a user and the cable. Accordingly, adjustment of the position of the carriage with respect to the frame, and the resulting adjustment to the braking force, may safely be accomplished in any suitable manner while the trolley including the carriage and frame is in motion along the cable. In certain embodiments, absent contrary inputs or forces, a carriage may, under the impetus of gravitational acceleration, move toward the second position. At the second position, the braking force may be at a maximum. Accordingly, a trolley in accordance with the present invention may have a default configuration corresponding to maximum braking, which, given typical cable declination, is sufficient to bring the trolley to a halt, such as in the event of any failure of the trolley. Trolleys in accordance with the present invention may be used as the basis for an amusement ride. For such rides, revenue may largely depend on the number of operators employed to operate the ride and the number of users served within a given period of time. Accordingly, a trolley retrieval system in accordance with the present invention may be configured to maximize user throughput, minimize operator interaction, and increase safety. In selected embodiments, a trolley retrieval system may include multiple cables held in suspension between first and second supports. A retrieval line may be suspended in an open line or in a closed loop extending from proximate a start area to proximate a finish area. A closed loop is more readily controllable and less likely to tangle or fail to deploy properly. A motivator (e.g. motor) may selectively circulate the retrieval line back and forth or around the loop. A controller may control operation of the motivator. In certain embodiments, a controller may include a processor and one or more sensors. The sensors may be operably connected to the processor to pass thereto a stop signal informing the processor that one or more of trolleys is sufficiently near the start area. The processor may be programmed to issue, in response to the stop signal, a stop command causing the motivator to cease circulation or other operation of the retrieval line. The processor may be further programmed to issue, in further response to the stop signal, a reverse command causing the motivator to reel in or circulate the retrieval line in an opposite direction when it resumes circulation of the retrieval line. For example, a motive source may comprise an electric motor. In such an embodiment, the controller of such a motivator may include a polarity switch switching, in response to the reverse command, the polarity of the current supplied to the electric motor. A controller may further include a retrieval switch operably connected to cause, when activated, the motivator to resume circulation of the retrieval line. In operation, an amusement ride in accordance with the present invention may begin with selection of a system comprising one or more cables held in suspension between first and second supports and a trolley positioned to travel along each cable. A user may then be connected to the trolley. Following securement of a user into a harness or possibly of a harness or seat of a user thereto, the trolley may be released to travel along the cable from proximate the start area to proximate the finish area. At the finish area, the user may be disconnected from the trolley. The trolley may then be connected to a retrieval line. Safety will usually favor fastening a user into a harness already connected to the main support cable rather than connecting and disconnecting harnesses and trolleys from a main support cable. Once a trolley is connected to a retrieval line, the motivator may be activated to draw the trolley along the cable from proximate the finish area to proximate the start area. When one or more of the trolleys connected to a retrieval line activates a sensor, the motivator may stop the retrieval line. The trolley or trolleys may then be disconnected from the retrieval line and secured for future use. As stated hereinabove, in selected embodiments, a processor may be programmed to issue, in response to a stop signal, a reverse command causing the motivator to circulate the retrieval line in an opposite direction when it resumes circulation of the retrieval line. So configured, the engagement locations between a retrieval line and a trolley may travel in a cycle from the starting (e.g. loading, launching) area to the finishing (e.g. end, unloading) area and back. Moreover, while one engagement location is stopped at the starting area, another may be stopped at the finish area. Accordingly, while one or more trolleys are being loaded with users, other trolleys may be connected to a retrieval line. Also, while one or more trolleys are towed or pulled back up from the finish area to the start area, other engagement locations on the retrieval line may be returning to the finish to continue the cyclical pattern. So configured, a trolley retrieval system in accordance with the present invention may provide a substantially continuous throughput, minimize operator interaction, and increase safety. BRIEF DESCRIPTION OF THE DRAWINGS The foregoing features of the present invention will become more fully apparent from the following description and appended claims, taken in conjunction with the accompanying drawings. Understanding that these drawings depict only typical embodiments of the invention and are, therefore, not to be considered limiting of its scope, the invention will be described with additional specificity and detail through use of the accompanying drawings in which: FIG. 1 is a perspective view of one embodiment of a trolley and cable in accordance with the present invention; FIG. 2 is a perspective view of one embodiment of a sheave mount from a trolley in accordance with the present invention; FIG. 3 is a perspective view of one embodiment of a frame from a trolley in accordance with the present invention; FIG. 4 is a perspective view of a brake assembly from a trolley in accordance with the present invention; FIG. 5 is an exploded view of the brake assembly of FIG. 4; FIG. 6 is a perspective view of the trolley of FIG. 1, omitting a cheek plate and brake shoe of the brake assembly; FIG. 7 is a top, plan, cross-sectional view of one embodiment of a brake pad and brake shoes in accordance with the present invention; FIG. 8 is a top, plan, cross-sectional view of an alternative embodiment of a brake pad and brake shoes in accordance with the present invention; FIG. 9 is a top, plan, cross-sectional view of another alternative embodiment of a brake pad and brake shoes in accordance with the present invention; FIG. 10 is a top, plan, cross-sectional view of another alternative embodiment of a brake pad and brake shoes in accordance with the present invention; FIG. 11 is a side, elevation view of an alternative embodiment of a trolley applying to a cable minimum braking in accordance with the present invention; FIG. 12 is a side, elevation view of the trolley of FIG. 11 applying to a cable maximum braking in accordance with the present invention; FIG. 13 is a perspective view of the trolley of FIG. 11; FIG. 14 is another perspective view of the trolley of FIG. 11; FIG. 15 is a perspective view of an alternative embodiment of a capture in accordance with the present invention; FIG. 16 is a partial, top, plan view of a trolley retrieval system in accordance with the present invention; FIG. 17 is a partial, perspective view of a line engagement system from a trolley retrieval system in accordance with the present invention; FIG. 18 is a schematic block diagram of a method for operating a trolley retrieval system in accordance with the present invention; FIG. 19 is a partial, top, plan view of an alternative embodiment of a trolley retrieval system in accordance with the present invention; FIG. 20 is a side, elevation view of a cable support in accordance with the present invention; FIG. 21 is a perspective view of a cable anchoring assembly in a slack-take-up mode in accordance with the present invention; and FIG. 22 is a perspective view of a cable anchoring assembly in a tied-off configuration in accordance with the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS It will be readily understood that the components of the present invention, as generally described and illustrated in the drawings herein, could be arranged and designed in a wide variety of different configurations. Thus, the following more detailed description of the embodiments of the system and method of the present invention, as represented in the drawings, is not intended to limit the scope of the invention, as claimed, but is merely representative of various embodiments of the invention. The illustrated embodiments of the invention will be best understood by reference to the drawings, wherein like parts are designated by like numerals throughout. Referring to FIG. 1, in discussing a trolley 10 in accordance with the present invention, it may be advantageous to establish a coordinate system 11. Accordingly, a trolley 10 may be defined in terms of a longitudinal direction 11a, a lateral direction 11b, and a transverse direction 11c, substantially orthogonal to one another. A trolley 10 in accordance with the present invention may be configured for travel along a cable 12 in the longitudinal direction 11a. In general, a trolley 10 of the present invention may be applied to a cable 12 held in suspension by two or more supports. For example, as disclosed in U.S. Pat. No. 6,622,634 issued Sep. 23, 2003 and entitled AMUSEMENT RIDE EMPLOYING A SUSPENDED TENSIONED STATIC CABLE, which is incorporated herein by reference, a cable 12 may be supported between two supports (e.g., towers, platforms). A first support may hold one end of the cable 12 at a higher elevation than a second support holds the other end of the cable 12. Accordingly, a trolley 10 secured to roll along the cable 12 may tend to travel from the first, upper support toward the second, lower support. While a suspended cable 12 may provide the basis for an amusement ride, other uses are also contemplated. For example, a suspended cable 12 may be used as part of a lift system transporting persons or goods over or up certain geologic obstacles. Suspended cables 12 are commonly used on ski lifts, gondolas, aerial trams, and the like. Similarly, suspended cables 12 have been incorporated into evacuation systems (e.g., oil derrick evacuation systems). Whether for repair, evacuation, or as part of the system itself, such suspended cable 12 systems often require a trolley 10 in accordance with the present invention. In selected embodiments, a frame 14 may provide the main structure of the trolley 10 or a base to which other components may secure. A frame 14 may be formed of any suitable material or combination of materials. Characteristics that may be considered when selecting the material for the frame 14 may include cost, formability, machineability, strength, rigidity, durability, corrosion resistance, density, etc. In certain embodiments, aluminum has been found to be a suitable material for a frame 14. A frame 14 may extend from a first end 16 to a second end 18. In certain embodiments, a brake assembly 20 may connect to the frame 14 proximate the first end 16 thereof. Proximate the second end 18, a bumper assembly 22 may connect to the frame 14. In one embodiment, a bumper assembly 22 may include a bumper 24 held between two cheek plates 26. In selected embodiments, a bumper 24 may be formed of a friction-reducing polymeric material (e.g., HDPE, UHMWPE, PTFE). In other embodiments, a bumper 24 may be formed of an elastomeric (e.g. rubber compound) material. A sheave mount 28 may connect to the frame 14 at a location between the brake assembly 20 and the second end 18. A sheave mount 28 may support one or more sheaves 30 positioned to roll along the cable 12. In selected embodiments, the portion 32 of the frame 14 between the sheave mount 28 and the second end 18 may be characterized as the user-suspension-portion 32. That is, the weight of a user may be directed to, and supported by, this portion 32 of the frame 14. In certain embodiments, the frame 14 of a trolley 10 in accordance with the present invention may be suspended below a cable 12 in the transverse direction 11c. A sheave mount 28 may extend upwardly from the frame 14, positioning a sheave 30 to roll on an upper surface of the cable 12. A brake assembly 20 may extend upwardly from the frame 12 to contact a lower surface of the cable 12. With the brake assembly 20 and user-suspension portion 32 on opposite sides of the sheave mount 28, the weight 34 of a user applied to the user-suspension portion 32 may generate a torque 36 or moment 36 urging the brake assembly 20 to “pitch” against the underside of the cable 12 (i.e., generate or urge rotation about an axis extending in the lateral direction 11b). The greater the moment 36 generated, the greater the braking force or friction force produced by the brake assembly 20. A carriage 38 may provide the primary interface between a user and a trolley 10 in accordance with the present invention. That is, while other locations, apertures, connection, structures, and the like may be used for redundant, fail-safe systems, in normal use, the majority of user weight 34 may be applied to the carriage 38. The carriage 38, in turn, may communicate that load to the frame 14. The position of the carriage 38 with respect to the frame 14 may be adjusted to provided a desired braking force. For example, the greater the distance 40 between the sheave mount 28 and the carriage 38, the greater the moment 36 and resulting braking force. The opposite may also be true. That is, the braking force may be minimized by minimizing the moment arm 40 over which the weight 34 of a user may act. Adjustability and securement between a carriage 38 and a frame 14 may be provided by any suitable structures. In selected embodiments, an array of apertures 42 may provide an array of positions at which a carriage 38 may be secured to a frame 14. A pin 44 or bolt 44 may pass through a carriage 38 and a selected aperture of the array 42 to lock the carriage 38 at a desired moment arm 40. Accordingly, a trolley 10 in accordance with the present invention may be tuned to a particular cable 12 arrangement. That is, a trolley 10 may be formed according to a single design, yet be flexible within that design to provide braking appropriate for a wide range of cable 12 arrangements. For example, given a first cable 12 arrangement involving a comparatively larger change in elevation, a trolley 10 traveling on such a cable 12 may tend to reach excessive speeds. Thus, the carriage 38 may be secured to the frame 14 at an aperture 46 in the array of apertures 40 providing a corresponding, comparatively larger moment arm 40. This greater moment arm 40 may increase the braking force and keep the trolley 10 within acceptable speed ranges. Conversely, consider a second cable 12 arrangement involving a minimal change in elevation. For such an arrangement, a carriage 38 secured at certain aperture (e.g., aperture 46) may provided excessive braking. For example, the resultant braking may cause the trolley 10 to stop without reaching the unloading area at the bottom of the cable 12. According, for such arrangements, a carriage 38 may be secured to the frame 14 at an aperture 48 in the array of apertures 40 providing a minimal moment arm 40. By so positioning the carriage 38, the trolley 38 may provide greater speed along the cable 12. While the weights of different users may vary, a trolley 10 in accordance with the present invention may automatically compensate for such variations. For example, the braking force required to regulate the speed of a trolley 10 carrying a user weighing 200 lbs. may be significantly greater than the braking force required to regulate the speed of a trolley 10 carrying a user weighing 100 lbs. However, with a single setting of the carriage 38 (i.e., a single moment arm 40), at trolley 10 may appropriately regulate the speed of both users. The braking force generated by a trolley 10 is equal to the coefficient of friction between the brake assembly 20 and the cable 12 multiplied by the normal force urging the braking assembly 20 against the cable 12. For a single moment arm 40, the only variable becomes the weight 34 of the user. Accordingly, the normal force urging the braking assembly 20 against the cable 12, which is result of the moment 36 applied by the weight 34 of a user to the frame 14, controls the braking force. Thus, without adjusting the position of the carriage 38, the braking force generated for a user weighing 200 lbs. user will automatically be roughly twice that generated for a user weighing 100 lbs. That is, a trolley 10 may be tuned to a particular cable 12 arrangement, but need not be tuned for each user. A trolley 10 in accordance with the present invention may include any desirable redundant or fail-safe systems. For example, in selected embodiments, a frame 14 may include a slot 50 within or along which the carriage 38 may travel. Accordingly, if the pin 44 holding the carriage 38 in a particular location were to fail, the carriage 38 would not be free to separate from the frame 14. Additionally, the orientation of the slot 50 with respect to the weight 34 of a user may urge an unpinned carriage 38 toward the end of the slot 50 corresponding to the second end 18 of the frame 14. At such a location, the moment arm 40 and corresponding braking force may be at a maximum. Accordingly, if a pin 44 were to fail, the link between the user and the cable 12 would not be lost and the trolley 10 would quickly be brought to a halt. Referring to FIG. 2, in selected embodiments, a sheave mount 28 in accordance with the present invention may be pivotably secured to a frame 14. For example, in certain embodiments, a bolt 52 may extend through the frame 14. If desired, a collar 54 may be positioned over the bolt 52 to improve wear resistance, increase the rigidity of the bolt 52, or the like. In certain embodiments, to increase safety, a sheave mount 28 may provide an enclosure capturing a cable 12 therewithin. That is, once the sheave mount 28 has received a cable 12 therewithin, it may resist inadvertent removal of that cable 12. For example, in one embodiment, a sheave mount 28 may include a first side 56 extending from the bolt 52 to an aperture 58 for supporting a sheave 30. This first side 56 may include one or more ribs 60 to increase the rigidity and strength thereof. A top 62 of the sheave mount 28 may connect the first side 56 to a second side 64 of the sheave mount 28. In selected embodiments, the second side 64 may control admittance and release of a cable 12 from within the sheave mount 28. In selected embodiments, the second side 64 of a sheave mount 28 may be separated into a hook portion 66 and a bail assembly 68. In one embodiment, the hook portion 66 may be connected to the top 62 and include an aperture 70 that, in combination with another aperture 58, may pivotably connect a sheave 30 to the sheave mount 28. A hook portion 66 may also include a hook 72. A bail assembly 68 may include a bail 74 and a bail mount 76. A bail mount 76 may connect to the bolt 52 or collar 54 extending through the frame 14 from the first side 56 of the sheave mount 28. A bail 74 may, in turn, extend from the bail mount 76 to engage the hook 72 of the hook portion 66. In selected embodiments, a bail 74 may be biased toward a closed position with respect to the hook 72. Accordingly, in certain embodiments, a bail 74 may be moved (e.g., pivoted) to permit entry of a cable 12 into the sheave mount 28. Once the cable 12 is captured with the sheave mount 28, the bail 74 may be released to return automatically to its preferred (biased), closed position. In selected embodiments, the interface between a bail 74 and a hook 72 may be such that the bail 74 is configured to open only toward the interior of the sheave mount 28. Thus, the bail 74 may be biased to permit entry of a cable 12 into the sheave mount 28 but resist inadvertent removal of that cable 12. As an additional safety feature, in certain embodiments, a bail mount 76 may include a slotted aperture 78 extending therethrough to receive the bolt 52, collar 54, or some combination thereof. A tensioner 80 may control the position of the bolt 52, collar 54, etc. within the slotted aperture 78. Accordingly, once a cable 12 has been received within a sheave mount 28 and the bail 74 has returned to a closed position, the tensioner 80 may be adjusted to move the bail assembly 68 with respect to the bolt 52, collar 54, etc. Thus, the bail 74 may be pulled 82 firmly into engagement with the hook 72. In such an arrangement, the hook 72 may resist opening of the bail 74. Additionally, the bail assembly 68 may assist in transferring loads from a sheave 30 to the frame 14 of the trolley 10. That is, the first side 56 of the sheave mount 28 need not act alone, thereby increasing the load-bearing capacity, and corresponding safety factor, associated with the sheave mount 28. Referring to FIG. 3, in selected embodiments, a trolley 10 in accordance with the present invention may include a brake assembly 20 that is pivotably secured to the frame 14. A pivotable connection between a brake assembly 20 and a frame 14 may support a more controlled and even wear on the break assembly 20. In certain embodiments, to provide a pivoting securement between a brake assembly 20 and a frame 14, the frame 14 may include various apertures 84, 86. A pivot aperture 84 may be sized and shaped to receive a pivot bolt (i.e., a bolt about which the brake assembly 20 may pivot). A limiting aperture 86 may be sized and shaped to receive a limiting bolt (i.e., a bolt moving with the brake assembly 20 and abutting the extremes of the limiting aperture 86 when the brake assembly 20 reaches a desired limit to its pivoting). In selected embodiments, a frame 14 may include multiple pivoting apertures 84a, 84b, 84c. For example, a first pivoting aperture 84a may provide a pivot point (e.g., central pivot point) for a brake assembly 20 of a first size. A second pivoting aperture 84b may provide a pivot point for a brake assembly 20 of a second, smaller size. A third pivoting aperture 84c may provide a pivot point for a brake assembly 20 of a third, even smaller size. If desired, multiple limiting apertures 86 may be provided. In one embodiment, however, a single limiting aperture 86 may be sized and shaped to providing a limiting effect to brake assemblies 20 pivoting in any of the various pivoting apertures 84. Referring to FIGS. 4 and 5, a brake assembly 20 in accordance with the present invention may provide significant adjustability. For example, a brake assembly 20 may include a brake pad 88 that may be removed and replaced, as wear so dictates. Additionally, a brake pad 88 may itself be adjustable to provide a desired or customized braking effect. In selected embodiments, a brake pad 88 may comprise a plurality of interchangeable brake pad segments 89. Thus, the sequence, composition, gaps, and the like of the various segments 89 may be selected to provide a desired resistance to wear, frictional coefficient, all-weather braking, and the like. In certain embodiments, the various segments 89 of a brake pad 88 may be held in place by one or more brake shoes 90. For example, in one embodiment, a first brake shoe 90a may engage one side of the brake pad 88, while a second brake shoe 90b may engage the other side of the brake pad 88. Accordingly, in such an embodiment, the brake shoes 90 may securely hold the brake pad 88 therebetween. In selected embodiments, the brake pad 88 and one or more brake shoes 90 may be configured to facilitate mutual engagement. For example, in one embodiment, the various segments 89 of a brake pad 88 may include one or more extensions 92. The brake shoes 90 may include one or more recesses 94 shaped and sized to receive the extensions 92. Accordingly, when assembled, the brake shoes 90 may secure the brake pad 88 in all three dimensions 11a, 11b, 11c. If desired or necessary, a brake assembly 20 may include various structural members providing additional strength, rigidity, safety, or the like. For example, in selected embodiments, a brake assembly 20 may include one or more cheek plates 96. In one embodiment, a brake assembly 20 may include a first cheek plate 96a positioned to reinforce a first brake shoe 90a and a second cheek plate 96b positioned to reinforce a second brake shoe 90b. In certain embodiments, a cheek plate 96 may include various apertures to support desired functionality. For example, a cheek plate 96a may include an aperture 98 sized and positioned to receive a limiting bolt, one or more apertures 100 sized and positioned to receive a pivot bolt, and one or more apertures 102 sized and positioned to receive assembly bolts or bolts securing the brake assembly 20 together. In selected embodiments, corresponding apertures 98, 100, 102 may be formed in other cheek plates 96b, as well as the various brake shoes 90. In selected embodiments, a brake assembly 20 may include a groove 104 or slot 104 sized and positioned to accommodate a portion of the frame 14 therewithin. Accordingly, in such embodiments, a brake assembly 20 may effectively straddle the frame 14, permitting various fasteners (e.g., pivot bolts, limiting bolts, etc.) to pass through both the brake assembly 20 and the frame 14. If desired or necessary, a slot 104 may extend some distance less than the entire length of the brake assembly 20. For example, in one embodiment, opposing brake shoes 90a, 90b may each include a shoulder 106 extending to meet the other. The shoulders 106 may effectively close the slot 104. Accordingly, any fastener (e.g., assembly bolt) passing through the area of the shoulder 106 may be tightened without clamping the frame 14 and reducing the ability of the brake assembly 20 to pivot with respect to the frame 14. A brake assembly 20 in accordance with the present invention may include a capture 108. A capture 108 may secure a cable 12 therewithin. That is, once a trolley 10 is applied to a cable 12, the capture 108 may secure the brake assembly 20 to the cable 12. Accordingly, the capture 108 may provide a redundant safety mechanism and, should there be a catastrophic failure of the sheave mount 28, the trolley 10 may be secured to the cable 12 via the brake assembly 20 and capture 108. If desired, a capture 108 may include a slide 110. In certain embodiments, a slide 110 may provide an interface between a capture 108 and a cable 12. For example, a capture 108 may in certain situations slide along a cable 12. In such situations, a slide 110 may prevent abrasion or grinding that may reduce the structural integrity of the capture 108. In one embodiment, a slide 110 may include a groove 112 or slot 112 providing a preferred or default location of engagement between a slide 110 and a cable 12, should contact occur therebetween. Referring to FIG. 6, a capture 108 in accordance with the present invention may have any suitable shape or configuration. Additionally, a capture 108 may secure to the rest of the brake assembly 20 in any suitable manner. For example, in one embodiment, a capture 108 may be positioned and secured to bracket the rest of the brake assembly 20. Such bracketing may improve the structural integrity of the brake assembly 20 without requiring additional fasteners (e.g., bolts), which may interfere with the adjustability or functionality of the brake assembly 20. Portions of the capture 108 may be held in place by one or more bolts extending in the lateral direction 11b through the brake assembly 20. For example, in one embodiment, a capture 108 may be held in place by a limiting bolt 114 and an assembly bolt 116. Referring to FIG. 7, various material properties and characteristics may be considered when selecting a material for a brake pad 88 in accordance with the present invention. Properties and characteristics that may be considered include cost, availability, machineability, wear resistance, toughness, all weather performance (e.g., characteristics at various conditions of humidity, moisture, corrosion, temperature, and the like), coefficient of friction against a cable 12 in various weather conditions (e.g., temperature and wetness levels), and the like. Often a material that has certain advantageous characteristics may have others that are disadvantageous. For example, one material may have excellent wear resistance, but its coefficient of friction against a cable 12 may vary greatly depending on whether the cable is dry. Accordingly, the material may be suitable for dry conditions, yet be hazardous for wet conditions. In certain embodiments of a trolley 10 in accordance with the present invention, it may be advantageous to provide a brake pad 88 having repeatable and consistent performance with respect to wear, coefficient of friction, or the like regardless of temperature, wetness, etc. For example, by providing a brake pad 88 with consistent wear, fixed maintenance schedules may be determined and executed. The resulting decrease in subjectivity may be accompanied by an increase in consistency and safety. Similarly, by providing a brake pad 88 with a consistent coefficient of friction regardless of the wetness of the cable 12, rain need not concern an operator of a trolley 10 in accordance with the present invention. Again, the resulting decrease in subjectivity and weather dependence may be accompanied by an increase in consistency and safety. In selected embodiments, a brake pad 88 may be configured to operate within a specific range. For example, a brake pad 88 may perform within a range, regardless of environmental temperature and the wetness or dryness of a cable 12. A brake pad 88 may deliver a rider to the bottom end of a cable 12 at a first speed in a dry environment at 90 degrees Fahrenheit. That same brake pad 88 may deliver a rider to the bottom end of a cable 12 at a second speed, different from the first speed, in a wet (e.g., saturated cable 12) environment at 65 degrees Fahrenheit. However, the difference between the first and second speeds may be such that both are within an acceptable range. For example, while the first may be 20 miles per hour and the second may be 27 miles per hour, both speeds may be below a hypothetical safety cutoff of 35 miles per hour. To provide the advantages of a brake pad 88 in accordance with the present invention, a brake pad 88 may be formed of various segments 89 The various segments 89 may be formed in various shapes and of various materials. As stated hereinabove, the shape of the various segments 89 may support engagement with the rest of the brake assembly 20 (e.g., the brake shoes 90). The shape of the various segments 89 may also control the contact area between a segment 89 and a cable 12. In selected embodiments, a brake pad 88 may include a plurality of segments 89 positioned in series. So positioned, the width of each segment 89 in the longitudinal direction 11a may control the contact area between each segment 89 and the cable 12. The contact area may vary between segments 89. For example, in certain embodiments, one segment 89a may have a width 118 greater than the width 120 of another segment 89b. Accordingly, the former segment 89a may provide a greater contribution to the overall performance of the brake pad 88 than the latter segment 89b. Although friction forces are independent from the area engaged, wear is not. If desired, gaps 122 may be included between various segments 89 of a brake pad 88. In certain embodiments, gaps 122 may improve the all weather performance of a brake pad 88. For example, when a cable 12 is saturated with water, the gaps 122 may provide locations for the water to escape from between the cable 12 and a segment 89 being pressed thereagainst. The size 124 or width 124 of the gaps 122 in a brake pad 88 may vary from a minimum of direct abutment between adjacent segments (e.g., segment 89a and segment 89b) to some maximum. By controlling the composition of the segments 89, the contact area of the segments 89, and the gaps 122 between the segments 89, the performance of a brake pad 88 may be optimized to a given trolley 10 application. For example, in selected embodiments, it may be desirable for a brake pad 88 in accordance with the present invention to slide along a cable 12. That is, the brake pad 88 may lower the speed of the trolley 10 along the cable 12, but not overly slow or stop it. Accordingly, in one embodiment, certain segments 89a, 89c, 89e, 89g may be formed of a first, substantially inelastic material (e.g., high density polyethylene (HDPE) or ultra high molecular weight polyethylene (UHMWPE)). The rest of the segments 89b, 89d, 89f, 89h may be formed a second, elastic material (e.g., multi-rubber or other natural or synthetic elastomeric materials such as those used for the caliper brake pads of a bicycle). So arranged, the first material may provide the desired wear resistance and a suitable (e.g., limited) frictional engagement with a dry cable 12. The second material may not wear as well as the first material, yet provide a suitable water stripping or frictional engagement with a wet cable 12. Accordingly, overall, the brake pad 88 may have both acceptable wear and frictional engagement even when applied to a wet cable 12. By adjusting the number of segments 89 corresponding to the first and second materials and the contact areas associated with those segments 89, a proper balance of characteristics may be achieved. Referring to FIG. 8, in selected embodiments, two materials and two larger gaps 122 may be all that is required to provide a satisfactory brake pad 88. Additionally, for optimum performance, the contact area between the two materials may only slightly favor one material over the other. In such an embodiment, a first plurality of segments 89a, 89c, 89e, 89g, 89i may be formed of a first material. A second plurality of segments 89b, 89d, 89f, 89h may be formed of a second material. If desired, the segments 89 may be positioned in an alternating pattern. Accordingly, each segment 89 of the second material may be positioned between segments 89 corresponding to the first material. Alternatively, the segments 89a, 89c, 89e, 89g, 89i comprising the first material may be positioned adjacent one another, and the segments 89b, 89d, 89f, 89h comprising the second material may be positioned adjacent one another. In such an embodiment, the segment 89a, 89c, 89e, 89g, 89i comprising the first material may be consolidated into a single monolithic (i.e., seamless) unit. Similarly, the segments 89b, 89d, 89f, 89h comprising the second material may be consolidated into a single monolithic unit. Referring to FIG. 9, in selected embodiments, two materials and minimal gaps 122 may be all that is required to provide a satisfactory brake pad 88. Additionally, for optimum performance, the contact area between the two materials may favor one material over the other (e.g., 75 percent one material, 25 percent another). In such an embodiment, a first plurality of segments 89a, 89c, 89e, 89g, 89i may comprise a first material. A second plurality of segments 89b, 89d, 89f, 89h may comprise a second material. Again, the segments 89 may be positioned in an alternating pattern. Alternatively, the segments 89a, 89c, 89e, 89g, 89i comprising the first material may be positioned adjacent one another and the segments 89b, 89d, 89f, 89h comprising the second material may be positioned adjacent one another. Adjacent segments 89 of common material may be consolidated as desired. Referring to FIG. 10, in selected embodiments, more than two materials 122 may be required to provide an optimal brake pad 88. For example, for optimum performance, three materials may be needed in varying degrees (e.g., contact area comprising 45 percent of a first material, 30 percent of a second material, and 25 percent of the last material). In such an embodiment, a first plurality of segments 89a, 89e, 89i may comprise a first material. A second plurality of segments 89c, 89g may comprise a second material. A third plurality of segments 89b, 89d, 89f, 89h may comprise a third material. Again, the segments 89 may be positioned in an alternating or distributed (e.g., balanced) pattern. Alternatively, the segments 89 may be separated and arranged by material type, and, if desired, consolidated into a minimum number of segments 89 (e.g., only one segment 89 for each type of material). Referring to FIGS. 11 and 12, in selected embodiments, a trolley 10 in accordance with the present invention may provide a user readily adjustable, or even “on-the-fly,” control over the magnitude of a braking force 126 or friction force 126 generated by the trolley 10 as it travels along a cable 12. The braking force 126 may be equal to the normal force 128 urging the brake assembly 20 against the cable 12 multiplied by the friction coefficient for the brake pad 88 against the cable 12. With the friction coefficient for the brake pad 88 against the cable 12 being substantially constant, the braking force 126 may perhaps most easily be manipulated by manipulations of the normal force 128. For example, by adjusting the moment arm 40 at which the weight 34 of a user is applied to the frame 14 of a trolley 10, the magnitude of the resulting moment 36 may be controlled. The magnitude of the moment 36 may then dictate the magnitude of the normal force 128. Accordingly, by adjusting the moment arm 40 at which the weight 34 of a user is applied to the frame 14 of a trolley 10, a user may control, within a particular range, the braking force 126 generated by the trolley 10. In selected embodiments, a trolley 10 in accordance with the present invention may include a carriage 38 configured to travel along a frame 14 or portion of a frame 14 through a range (e.g., continuous range) of motion bounded by a first position of the carriage 38 proximate the sheave mount 28 (e.g., the position of the carriage 38 in FIG. 11) and a second position of the carriage 38 proximate a second end 18 of the frame 14 (e.g., the position of the carriage 38 in FIG. 12). In certain embodiments, a carriage 38 may travel along the frame 14 through the range of motion bounded by the first and second positions without compromising the connection between a user and the cable 12. Accordingly, adjustment of the position of the carriage 38, and the resulting adjustment to the braking force 126, may safely be accomplished in any suitable manner while the trolley 10 is in motion along the cable 12. That is, in selected embodiments, neither a stopped trolley 10 nor any change in the connection between a user and a cable 12 may be necessary to transition from minimum leverage and braking to maximum leverage and braking. In selected embodiments, the default position of a carriage 38 with respect to the frame 14 may be the second position (e.g., the position of the carriage 38 in FIG. 12). That is, absent contrary inputs or forces, a carriage 38 may, under the impetus of gravitational acceleration, move toward the second position. At the second position, the braking force 126 may be at a maximum. Accordingly, a trolley 10 in accordance with the present invention may have a default configuration corresponding to maximum braking, which, given typical cable 12 declination, is sufficient to bring the trolley 10 to a halt. Referring to FIGS. 13 and 14,
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