{"id":538,"date":"2026-05-22T07:05:41","date_gmt":"2026-05-22T07:05:41","guid":{"rendered":"https:\/\/rock-crusher-tractor.com\/?p=538"},"modified":"2026-05-22T07:05:41","modified_gmt":"2026-05-22T07:05:41","slug":"kit-drawbar-stone-crusher-korean-orchard-slope-guide","status":"publish","type":"post","link":"https:\/\/rock-crusher-tractor.com\/de\/kit-drawbar-stone-crusher-korean-orchard-slope-guide\/","title":{"rendered":"Kit Drawbar Explained \u2014 Why Korean Orchard and Mountain Farm Operators Demand It"},"content":{"rendered":"
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Kit Drawbar Explained \u2014 Why Korean Orchard and Mountain Farm Operators Demand It<\/h1>\n

The standard rear-hitch mounting becomes unstable above 20% slope. The Kit Drawbar solves this \u2014 here is the physics, the mechanics, and when you need it for Korean mountain farm conditions.<\/p>\n

Ask About the THOR 2.4 for Your Orchard<\/a><\/p>\n<\/div>\n<\/div>\n

<\/p>\n

Korean mountain orchards \u2014 apple and pear in Gyeongsangbuk-do, citrus and hallabong on Jeju Island, persimmon in South Gyeongsang \u2014 share a common characteristic: slope. The terraced, hillside, and valley-wall positions that produce the air drainage, light exposure, and temperature moderation conditions favorable for premium fruit production are also the positions that create serious challenges for tractor-implement operation. Slopes of 15\u201330% \u2014 the typical gradient range across much of Korea’s commercial orchard country \u2014 are where the limitations of standard rear three-point hitch implement mounting become genuinely dangerous.<\/p>\n

The Kit Drawbar, included as standard with the THOR 2.4 stone crusher<\/a>, converts the machine from rear-hitch mounting to a front-pull (drawbar) configuration that changes the physics of slope operation in ways that directly improve safety, traction, and working quality. This guide explains exactly what that conversion achieves \u2014 the mechanics, the practical conditions that call for it, and how to set it up correctly.<\/p>\n

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The Physics of Rear-Hitch Implement Mounting on Slopes<\/h2>\n

\"THOR<\/p>\n

To understand what the Kit Drawbar does and why it matters, it is necessary first to understand the problem it solves: the mechanical instability that rear-hitch implement mounting creates on steep slopes.<\/p>\n

The Rear-Hitch Lever Effect on Slopes<\/h3>\n

A tractor is a four-wheeled machine that maintains stability by keeping its center of gravity within the footprint defined by its four wheel contact points. On level ground, a rear-mounted implement’s weight adds to the rear axle load \u2014 this increases rear wheel traction (generally beneficial) but also adds a rearward moment (torque) around the rear axle that tends to lift the front wheels. Modern tractors compensate for this with front ballasting, and the geometry keeps the center of gravity within the stability footprint.<\/p>\n

On a slope \u2014 particularly ascending grade \u2014 the geometry changes in a way that compounds this problem. Consider a tractor with a 2,300 Kg stone crusher on its rear three-point hitch, ascending a 25% slope:<\/p>\n

The slope angle tilts the entire tractor-machine combination rearward.<\/strong> The weight of the machine, which acts downward from its center of gravity, now has a larger horizontal component relative to the tractor’s rear axle than on level ground. The moment arm of this force \u2014 the distance from the machine’s weight center to the rear axle pivot point \u2014 effectively increases with slope angle.<\/p>\n

The front axle becomes increasingly unloaded.<\/strong> The rear-mounted implement weight, amplified by the slope geometry, transfers load from the front axle to the rear, progressively lifting the front wheels off the ground as slope angle increases. At some slope angle \u2014 determined by the machine weight, its position behind the rear axle, the tractor’s wheelbase and weight distribution, and the front ballasting \u2014 the front wheels lose ground contact.<\/p>\n

Steering becomes impossible.<\/strong> A tractor with front wheels off the ground cannot be steered \u2014 the steering system controls the front wheels, which no longer have ground contact to provide directional control. The tractor follows the slope direction and gravity, not the operator’s input.<\/p>\n

On a 25% gradient orchard slope with a 2,300 Kg stone crusher on the rear hitch, this loss of front wheel contact can occur at gradients well within the normal Korean mountain orchard operating range. Korean mountain orchard operators experienced exactly this problem before the Kit Drawbar solution \u2014 tractors working between orchard rows on slopes above 20% with heavy rear-hitch implements were experiencing front-axle lift, traction loss, and directional control loss. This is the specific problem the Kit Drawbar was designed to solve.<\/p>\n

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How the Kit Drawbar Changes the Weight Distribution<\/h2>\n

\"THOR<\/p>\n

The Kit Drawbar converts the THOR 2.4 from rear three-point hitch mounting to a front-pull (drawbar) configuration. In this configuration, a drawbar extends from the front of the THOR 2.4’s frame and connects to the tractor’s rear drawbar hook \u2014 the fixed attachment point positioned at approximately the rear axle centerline. The stone crusher is now towed in front of (rather than behind and above) the rear axle in the direction of travel.<\/p>\n

The Mechanical Change and Its Consequences<\/h3>\n

In the standard rear three-point hitch configuration, the machine is suspended from the hitch linkage above and behind the rear axle. The machine’s weight creates a moment (torque) around the rear axle that lifts the front axle.<\/p>\n

In the Kit Drawbar pull-mode configuration, the machine is connected to the rear drawbar hook at approximately the rear axle centerline. The machine’s weight now acts vertically downward from a point approximately at the rear axle \u2014 not behind it. The moment arm of the machine’s weight relative to the rear axle is dramatically reduced. Instead of a large rearward-lifting moment, the machine weight now acts predominantly as a vertical load on the rear axle \u2014 pressing the rear tyres into the ground without the front-lifting effect.<\/p>\n

The 2,300 Kg machine weight that in rear-hitch configuration was lifting the front axle now, in pull-mode configuration, presses both rear tyres down more firmly while preserving front axle ground contact. The practical outcomes of this weight redistribution on slopes above 20%:<\/p>\n

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Front Axle Stays Grounded<\/p>\n

The tractor maintains full steering control at all working gradient angles up to the Kit Drawbar’s rated slope limit. The operator directs the machine precisely between orchard rows, along field boundaries, and around obstacles without the loss of directional control that front-axle lift produces.<\/p>\n<\/div>\n

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Rear Tyre Traction Maintained<\/p>\n

The rear tyres remain firmly loaded against the slope surface. On steep Korean mountain orchard gradients where rear wheel slip is a risk with a rear-hitch implement (because some of the axle load is going into lifting the front rather than pressing the rear), pull-mode maintains consistent rear wheel traction for continuous forward progress.<\/p>\n<\/div>\n

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Reduced Overall Rollover Risk<\/p>\n

Lateral stability (resistance to sideways rollover on cross-slope sections) is also improved because the combined tractor-machine center of gravity is lower in pull-mode than in rear-hitch mode \u2014 the machine’s weight acting near the rear axle, rather than high and behind it, lowers the effective center of gravity of the combined system.<\/p>\n<\/div>\n<\/div>\n

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Setting Up the Kit Drawbar \u2014 What the Conversion Involves<\/h2>\n

The Kit Drawbar is included with every THOR 2.4 at no additional cost \u2014 it is a standard component, not an optional upgrade. The conversion from standard rear three-point hitch mode to pull-mode is described by Watanabe as taking under 10 minutes and requiring no tools. The conversion involves:<\/p>\n

Disconnecting the three-point linkage arms:<\/strong> The lower link arms of the tractor’s three-point hitch are disconnected from the THOR 2.4’s hitch attachment points. The top link (position control) is also disconnected.<\/p>\n

Attaching the Kit Drawbar connection:<\/strong> The Kit Drawbar \u2014 a structural drawbar frame extending from the front of the THOR 2.4’s main frame \u2014 is connected to the tractor’s rear drawbar hook via a pin connection. The stone crusher now hangs behind the tractor, connected at approximately rear-axle height rather than suspended from the upper hitch linkage points.<\/p>\n

Ground support adjustment:<\/strong> In pull-mode, the THOR 2.4 rides on its own support skids and the rear wheels of the machine (if equipped), rather than being lifted clear of the ground by the three-point hitch. The machine’s ground contact pressure distributes between these support points \u2014 confirming correct ground contact before starting the working pass is part of the pull-mode setup check.<\/p>\n

PTO shaft angle check:<\/strong> In pull-mode, the geometry of the PTO drive shaft between tractor and machine changes relative to rear-hitch mode. Confirm that the PTO shaft universal joint angles are within the permitted range (typically \u00b115\u00b0 from parallel) in the actual pull-mode operating position before engaging the PTO. Excessive shaft angle causes vibration and accelerated universal joint wear.<\/p>\n

Operating in Pull-Mode \u2014 Practical Differences<\/h3>\n

Several operational characteristics change when transitioning from rear-hitch to pull-mode:<\/p>\n

Turning radius:<\/strong> In rear-hitch mode, the stone crusher turns with the tractor on a relatively tight radius. In pull-mode, the machine is towed \u2014 it follows the tractor path but requires a larger effective turning radius because the machine swings wide on tight turns (like a trailer). Korean mountain orchard operators in pull-mode account for this additional turning envelope at headland turns, leaving adequate clearance from orchard trees and boundary structures.<\/p>\n

Reversing:<\/strong> Pull-mode implements cannot be reversed in a straight line \u2014 the machine will jackknife toward the tractor if reversed. Korean pull-mode operators plan their working pattern to minimize the need for reversing, typically using wide headland turns to return to the next working pass without reversing. For orchard rows that are too short for a wide turn, a brief return to three-point hitch mode for the turnaround may be necessary.<\/p>\n

Depth control:<\/strong> In rear-hitch mode, the tractor’s hydraulic hitch controls the machine’s working depth relative to the ground. In pull-mode, the machine rides on its own ground contact supports \u2014 working depth is controlled by the support skid height adjustment rather than the tractor hydraulic position. Correct working depth setting is part of the pull-mode setup procedure.<\/p>\n

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When to Use Pull-Mode vs Standard Rear-Hitch \u2014 Field Decision Guide<\/h2>\n

The Kit Drawbar is not needed on every application \u2014 it is the solution for a specific set of slope conditions where standard rear-hitch operation becomes unsafe or operationally impractical. Use this guide to determine which configuration is appropriate for your specific working conditions:<\/p>\n

\n\n\n\n\n\n\n\n\n\n\n
Field Condition<\/th>\nRear-Hitch Mode<\/th>\nPull-Mode (Kit Drawbar)<\/th>\n<\/tr>\n<\/thead>\n
Flat to gentle slope (0\u201310%)<\/td>\nPreferred \u2014 simple, tight turns<\/td>\nNot needed<\/td>\n<\/tr>\n
Moderate slope (10\u201320%)<\/td>\nAcceptable with adequate ballasting<\/td>\nOptional \u2014 use if front lift observed<\/td>\n<\/tr>\n
Steep slope (20\u201330%) \u2014 typical Korean mountain orchards<\/td>\nNot recommended \u2014 front lift risk<\/td>\nRequired for safe operation<\/td>\n<\/tr>\n
Very steep slope (above 30%)<\/td>\nDangerous \u2014 do not use<\/td>\nUse with caution; confirm tractor spec<\/td>\n<\/tr>\n
Tight row spacing (2\u20134 m centres)<\/td>\nPreferred \u2014 tight headland turns<\/td>\nPossible but wider turning required<\/td>\n<\/tr>\n
Long straight sections, farm roads<\/td>\nEither acceptable on gentle grades<\/td>\nPreferred on slopes \u2014 fewer turns<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n

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Korean Orchard and Mountain Farm Conditions That Require Pull-Mode<\/h2>\n

Apple and Pear Orchards \u2014 Gyeongsangbuk-do<\/h3>\n

The primary apple and pear production zones of Gyeongsangbuk-do \u2014 Cheongdo-gun, Yeongcheon-si, Gunwi-gun, and Uiseong-gun \u2014 are distributed across the lower slopes and valley walls of the Taebaek and Sobaek mountain ranges. Commercial apple orchards in Cheongdo-gun are typically laid out on slopes of 15\u201330%, oriented for maximum solar exposure on south or southeast-facing aspects. Row spacing of 3.5\u20134.5 m accommodates tree canopy development and orchard management equipment access, but leaves limited clearance for stone clearing equipment on the steeper sections.<\/p>\n

Orchard operators in this region who adopted the THOR 2.4 for stone clearance and tree-row vegetation management consistently report that slopes above 20% require Kit Drawbar pull-mode for both safety and working quality. Below 20%, rear-hitch mode is manageable with proper front ballasting. Above 20%, pull-mode is required \u2014 the front-axle lift that rear-hitch mode produces on steeper sections reduces steering precision in tight rows to an unacceptable level.<\/p>\n

Citrus and Hallabong Farms \u2014 Jeju Island<\/h3>\n

Jeju Island’s topography is dominated by the volcanic cone of Mt. Hallasan and the surrounding basalt-derived agricultural plains and lower slopes. Most Jeju citrus farming is concentrated on the gentle-to-moderate slopes of the island’s lower flanks \u2014 typically 5\u201320% gradient \u2014 rather than on the steeper upper slopes. For most Jeju citrus operations, rear-hitch stone crusher operation is appropriate with adequate front ballasting on sections below 20%.<\/p>\n

However, Jeju’s additional challenge is the basalt rock surface itself. Jeju basalt is significantly harder and more abrasive than Korean mainland granite \u2014 sustained stone crushing in Jeju basalt conditions creates greater thermal load on the THOR’s oil-cooled transmission than in softer mainland granite. For Jeju operators running long clearing sessions in July\u2013August (the hot season coinciding with the annual basalt clearance cycle), the THOR’s oil cooling system provides the operational continuity that competing machines without dedicated cooling cannot match in this demanding combination of hard rock and hot ambient temperature.<\/p>\n

Mountain Farm Access Roads \u2014 Gangwon-do<\/h3>\n

Farm access road construction and maintenance in Gangwon-do’s highland areas \u2014 serving the apple, pear, and highland potato farms of Pyeongchang-gun, Hoengseong-gun, and Inje-gun \u2014 is the third major application where Kit Drawbar pull-mode provides genuine operational advantage. Mountain access roads in these areas routinely have gradient sections of 15\u201325%, with the occasional steeper hairpin section up to 30%.<\/p>\n

In pull-mode on mountain road construction, the THOR 2.4 acts as a towed implement \u2014 the tractor pulls it up the gradient while the rotor processes the road surface. Because the machine weight is borne by the drawbar connection near the rear axle rather than on the three-point hitch, the tractor can devote its full powered axle traction to forward progress on the slope rather than to supporting rear-hitch implement weight. Korean road contractors working on highland farm track construction report consistently better continuous progress on steep gradient sections in pull-mode compared to rear-hitch mode on the same gradient.<\/p>\n

What About the THOR 3.0 on Slopes?<\/h3>\n

The THOR 3.0 stone crusher<\/a> includes the same Drawbar Kit system and can be operated in pull-mode on slopes in the same way as the THOR 2.4. However, the THOR 3.0’s 3.0 m working width makes it physically unsuitable for many Korean mountain orchard inter-row applications where the row spacing is 3.5\u20134.0 m \u2014 regardless of the slope configuration. The THOR 3.0’s slope work capability is most relevant for mountain farm road construction and large-scale land clearing on open slope terrain, where the 3.0 m width is not constrained by row spacing. For inter-row orchard and narrow mountain terrace work, the THOR 2.4 is the appropriate model regardless of slope gradient.<\/p>\n

\"Soil<\/p>\n

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For Lighter Stone Loads \u2014 The EP-EW-4000 Rock Rake as an Alternative<\/h2>\n

Not every Korean mountain orchard slope condition requires the full crushing power of the THOR 2.4. On established orchard sites where annual frost-heave produces primarily small surface stones below 30\u201340 Kg, and where no large embedded boulders are present, the EP-EW-4000 Steinrechen<\/a> (75 HP minimum, 3.6 m working width, Cat. 2 hitch, 540 RPM PTO) provides an effective and lower-cost stone management solution. The rock rake sweeps surface stones into windrows without crushing them \u2014 allowing collection by stone picker or hand labor at windrow locations rather than processing the stone in-place.<\/p>\n

The rock rake operates at 75 HP \u2014 approximately the same tractor as the farm’s potato furrower and planter \u2014 which means it shares the existing farm tractor rather than requiring a 180 HP+ machine. On annual maintenance clearance passes of established orchards where the initial heavy-stone clearance has already been completed by the THOR 2.4, the rock rake is a cost-effective annual maintenance implement. The THOR 2.4 is the tool for the initial heavy clearance; the rock rake is the tool for annual maintenance once the large stones have been processed.<\/p>\n

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Frequently Asked Questions \u2014 Kit Drawbar and Slope Operation<\/h2>\n
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\nDoes the Kit Drawbar come with the THOR 2.4, or is it a separate purchase?<\/summary>\n

The Kit Drawbar is included as standard equipment with every THOR 2.4 purchased from Korea Watanabe \u2014 it is not an optional extra, an accessory kit, or an additional charge. Every THOR 2.4 delivered from Korea Watanabe local stock includes the Kit Drawbar as part of the standard machine. The decision to use pull-mode or standard rear-hitch mode depends on your field conditions \u2014 you have both options with every THOR 2.4 from day one.<\/p>\n<\/details>\n

\nWhat is the maximum slope rating for the THOR 2.4 in pull-mode?<\/summary>\n

The Kit Drawbar pull-mode is designed for slopes up to approximately 35\u00b0 gradient (approximately 70% slope grade). In standard rear-hitch mode, the practical safe operating gradient for most Korean operators is up to 25\u201330\u00b0. Above 35\u00b0 in either configuration, tractor stability concerns and soil erosion risk both increase significantly \u2014 consult your tractor operator’s manual for the tractor’s rated slope capability, and follow the tractor manufacturer’s guidelines on maximum operating gradient for tractor stability. Tractor stability on steep slopes depends on the combined tractor-machine system and on soil conditions underfoot \u2014 a firm dry surface has different tractor stability characteristics than a wet soil surface at the same gradient.<\/p>\n<\/details>\n

\nIs the pull-mode conversion safe for a single operator to perform?<\/summary>\n

Yes \u2014 Watanabe describes the Kit Drawbar conversion as a “practical and fast operation” taking under 10 minutes. The conversion is designed to be performed by a single tractor operator in the field without specialist tools. The pin connections between the drawbar and the tractor’s rear drawbar hook are standard agricultural implement connections that tractor operators in Korea handle routinely with all types of towed implements. The key checks to perform at each setup: confirm the drawbar pin is fully seated and locked; verify the PTO shaft angle is within the permitted range in the pull-mode geometry; and check that the machine’s ground support skids are correctly set for the working depth before engaging the PTO.<\/p>\n<\/details>\n

\nCan the THOR 2.4 be reversed on the slope while in pull-mode?<\/summary>\n

Reversing a pull-mode (towed) implement requires care \u2014 reversing with a towed implement tends to push the implement sideways (jackknife) unless the tractor and implement are perfectly aligned and the reversing speed is very slow. On a slope, reversing with the THOR 2.4 in pull-mode is particularly inadvisable \u2014 the machine weight and the slope gradient combine to create forces that can cause the machine to swing laterally even in slow reverse. Korean pull-mode operators plan their working patterns to avoid reversing: typically completing a full forward pass then making a wide forward headland turn to return to the next row, rather than reversing out of a row end. If a situation requires reversing, return the machine to three-point hitch mode before reversing where possible.<\/p>\n<\/details>\n

\nDo other stone crusher brands offer an equivalent pull-mode system?<\/summary>\n

Some competing stone crusher brands offer separate optional drawbar kits as accessories \u2014 distinct from the THOR 2.4’s Kit Drawbar, which is included as standard equipment. The mechanical principle is the same: converting from rear-hitch to drawbar-pull changes the weight distribution in ways that improve slope stability. The practical difference for Korean buyers is the cost structure (standard inclusion vs. additional purchase) and the availability of local technical support for the specific implementation. If comparing stone crusher options, confirm whether the competitor’s pull-mode system is a standard inclusion or an optional accessory, and verify that local technical support is available for setup and any field issues with the pull-mode configuration.<\/p>\n<\/details>\n

\nHow do I know if my orchard slope requires pull-mode or is manageable in rear-hitch mode?<\/summary>\n

The direct test: in rear-hitch mode on your steepest orchard section, observe the front wheel contact. If you can see visible front-axle lift \u2014 the front tyres losing firm contact with the ground \u2014 pull-mode is required. If you have a smartphone with an inclinometer app, measure the slope gradient on your working sections: below 15% gradient, rear-hitch mode is generally safe with adequate front ballasting; 15\u201320%, front ballasting is important and pull-mode should be considered; above 20%, pull-mode is recommended for slope stability and operational quality. For new operations on slopes you have not previously worked with a rear-mounted implement, our recommendation is to start your assessment in pull-mode and use rear-hitch mode only on sections where you have confirmed the front wheels maintain firm ground contact throughout the working pass.<\/p>\n<\/details>\n<\/div>\n

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Tell Us Your Orchard Slope and Row Spacing \u2014 We Confirm the Right Setup<\/p>\n

Typical slope gradient + row spacing + tractor HP \u2192 THOR 2.4 configuration recommendation with pull-mode or rear-hitch guidance specific to your Korean orchard or mountain farm conditions. THOR 2.4 with Kit Drawbar in Korea local stock, Ansan-si, Gyeonggi-do.<\/p>\n

Kontaktieren Sie uns jetzt<\/a><\/p>\n<\/div>\n

Herausgeber: Cxm<\/p>\n<\/div>","protected":false},"excerpt":{"rendered":"

Kit Drawbar Explained \u2014 Why Korean Orchard and Mountain Farm Operators Demand It The standard rear-hitch mounting becomes unstable above 20% slope. The Kit Drawbar solves this \u2014 here is the physics, the mechanics, and when you need it for Korean mountain farm conditions. Ask About the THOR 2.4 for Your Orchard Korean mountain orchards […]<\/p>","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_et_pb_use_builder":"","_et_pb_old_content":"","_et_gb_content_width":"","footnotes":""},"categories":[31],"tags":[],"class_list":["post-538","post","type-post","status-publish","format-standard","hentry","category-application-and-technical-guid"],"_links":{"self":[{"href":"https:\/\/rock-crusher-tractor.com\/de\/wp-json\/wp\/v2\/posts\/538","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/rock-crusher-tractor.com\/de\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/rock-crusher-tractor.com\/de\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/rock-crusher-tractor.com\/de\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/rock-crusher-tractor.com\/de\/wp-json\/wp\/v2\/comments?post=538"}],"version-history":[{"count":2,"href":"https:\/\/rock-crusher-tractor.com\/de\/wp-json\/wp\/v2\/posts\/538\/revisions"}],"predecessor-version":[{"id":540,"href":"https:\/\/rock-crusher-tractor.com\/de\/wp-json\/wp\/v2\/posts\/538\/revisions\/540"}],"wp:attachment":[{"href":"https:\/\/rock-crusher-tractor.com\/de\/wp-json\/wp\/v2\/media?parent=538"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/rock-crusher-tractor.com\/de\/wp-json\/wp\/v2\/categories?post=538"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/rock-crusher-tractor.com\/de\/wp-json\/wp\/v2\/tags?post=538"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}