01 What Is a Jib Extension?

A jib extension is the simple, mechanical answer to "I need a bit more reach." It's a fixed-length section — usually a tube or lattice piece — that pins or bolts onto the tip of the spider crane's main boom, extending the working radius beyond what the standard telescopic boom provides on its own. Risenmega's own spec sheet notes it plainly: the standard telescopic boom extends to 8.5 meters horizontally, and "optional jibs can increase vertical reach" beyond that baseline for jobs that need the extra meters.

What makes a jib extension the budget option is exactly what makes it limited:

• No hydraulics. It's a passive structural add-on — there's no cylinder, no independent luffing motion, no powered adjustment once it's pinned in place.
• Fixed angle. To change its position, the boom typically needs to come down and the jib re-pinned on the ground. You can't re-angle it mid-lift from the remote.
• Capacity trade-off. Adding length at the tip of the boom without a powered counter-adjustment increases leverage on the load moment, which is why longer jib configurations come with reduced rated capacity — the same physics that makes any crane's chart de-rate capacity as radius increases.

For a job that just needs a known, fixed amount of extra straight-line reach — say, clearing a parapet wall by a set distance on every lift — a jib extension does the job at a fraction of the cost of a powered attachment.

02 What Is a Hydraulic Fly Arm?

The hydraulic fly arm is a different category of attachment entirely. Instead of a fixed structural extension, it's a powered secondary arm with its own hydraulic cylinder, connected into the crane's hydraulic circuit and controlled from the same wireless remote used to run the rest of the machine. That's what lets it do two things a plain jib can't:

• Luff and re-angle on the fly. The operator adjusts the arm's position from the remote without lowering the boom or repositioning the crane.
• Work as a searcher hook. Because it can be angled independently of the main boom, it can reach past an obstruction — an overhang, an arch, an existing structural element — to land a load somewhere the main boom has no straight line to. A fixed jib can add length; it can't reach around something in the way.

This is the attachment for jobs where repositioning the whole spider crane mid-task would cost real time — and on a tight urban site, repositioning often means re-deploying all four outriggers and re-leveling from scratch, not just rolling forward a few feet.

03 Quick Comparison: Fly Arm vs. Jib Extension

04 Why Does the Hydraulic Fly Arm Cost More?

The price gap between the two comes down to what you're actually buying. A jib extension is a structural part — steel, pins, a certified load rating. A hydraulic fly arm is a small powered machine bolted onto a bigger one:

• Its own hydraulic circuit. A dedicated cylinder, hoses routed through or alongside the main boom, and valve control — all of it has to be engineered and pressure-tested to the same standard as the rest of the crane's hydraulics, not just structurally rated like a static jib.
• Integration with the crane's control and safety system. Because the arm moves independently, its position has to be readable by the crane's Load Moment Indicator (LMI) — the system that tracks boom angle, length, and load weight to prevent overloading. That means angle and position sensing built into the attachment itself, not just a load rating stamped on a plate.
• More moving parts, more precision manufacturing. A cylinder, seals, hydraulic fittings, and remote-control integration all add manufacturing and testing steps that a fixed jib simply doesn't require.
• The searcher-hook function. Being able to reach around an obstacle isn't just a longer stick — it requires the arm to hold position accurately at odd angles under load, which is a higher engineering bar than a fixed extension held at one angle.

Set against the alternative — renting a second, longer-reach crane, or repeatedly breaking down and repositioning the spider crane's outriggers every time the load path is blocked — the fly arm's premium is usually the cheaper option over the life of a project, even if the attachment itself costs more than a jib up front.

05 The Dashboard Difference: Why the Fly Arm Shows Up on Your Display

This is the detail that trips up a lot of buyers. Risenmega's spider crane platform runs on a Load Moment Indicator (LMI) — the safety system that continuously measures boom angle, boom length, and load weight, and feeds that data to the operator's wireless remote display panel to prevent overloading in real time.

A hydraulic fly arm is part of that same powered, sensed system. Because it luffs under hydraulic control, its angle and extension are tracked the same way the main boom's are, and that data appears on the same dashboard the operator is already watching. A jib extension, by contrast, is a passive structural piece — it doesn't move, doesn't have its own actuator, and isn't a sensed component of the powered system in the same way. Its effect on capacity is accounted for in the crane's load chart for that configuration, but it isn't something the LMI is actively reading and displaying moment-to-moment the way it does with a powered fly arm.

In practical terms: with a fly arm, the operator can watch reach and load update live on the display as they luff the arm around an obstacle. With a jib extension, the configuration is set on the ground before the lift starts, and the operator works within the load chart for that fixed setup.

06 Which One Should You Order?

07 Tonnage & Compatibility Notes

Neither attachment is a universal bolt-on across every model in Risenmega's 1–12+ ton spider crane range. Fly arm and jib pricing and rated capacity depend on the base crane's tonnage and boom length — a heavier lift or longer reach requirement calls for a heavier chassis underneath it, the same way it does for the crane's other attachments (clamp, grab, and fork capacities scale the same way). Before ordering, share your target tonnage, typical load weight, and the reach or obstacle-clearance distance you're working with, and Risenmega will confirm the exact rated configuration in your quote.

08 Frequently Asked Questions