Hoist Fitness Leg Extension/Leg Curl HD-3400

Hoist HD-3400 Leg Extension Machine

The Hoist HD-3400 is a selectorized leg extension machine that also runs leg curls, training quads and hamstrings from one seated position. It suits commercial floors, studios, hotels and serious home gyms that need both knee movements in a single station rather than two separate frames.

• Series — Hoist HD Dual
• Builds — Standard HD or heavy HDG
• Curl style — Seated with back support
• Users at once — One per station
• Best fit — Shared, multi-user leg floors

What the HD-3400 Does From One Seat

Both exercises run from the same seat, so a user sets their position once and stays there for the whole leg block.

That is the practical case for this frame. A knee extension and a knee curl are opposite directions of the same joint, and the HD-3400 handles both without asking anyone to move to a second station or reset their whole position mid-session. Load selection happens at the stack rather than with plates, which is why it sits alongside the other selectorized leg machines rather than the plate-loaded builds.

Is the HD-3400 built for home gyms or commercial floors? Hoist positions the HD Dual Series for facilities where floor space or budget is tight — hotels, universities, corporate rooms and studios. Home buyers own them too, and the build standard is the same either way. The rest of the Hoist Fitness collection covers dedicated stations if a single-purpose frame fits your plan better.

Setting Up Your Leg Extension Machine

Three things govern fit on this frame, and only two of them are settings you make.

1. Back pad — eight adjustments for varying leg lengths.
2. Range of motion — multiple adjustments for both exercises.
3. Roller pad — self-aligning, so the shin needs no setting.

Most machines in this category ask you to position the ankle roller as well; telescoping ankle rollers and numbered ankle positions are standard selling points across the market. Hoist removes that step here. One fewer decision per user is worth real time on a floor that turns over all day, and it is the setup step shared rooms get wrong most often.

The trade-off deserves stating plainly. Because no roller adjustment range is published, the shin side of the fit is what the frame gives you. For most users that is a simplification. For anyone with unusual lower-leg proportions, it is worth testing before the frame is anchored. If you are still weighing whether you need both movements at all, how extensions and curls differ covers the programming side.

Pick the build that suits your users and add the HD-3400 to your cart.

What Wears First on a Combo Frame

Almost every listing in this category sells steel. Very few tell you what actually wears out.

Hoist publishes both. In the commercial and light-commercial tiers, frame and body components carry ten years and structural moving parts carry five. Pulleys, bearings and bushings carry three. Upholstery, grips and coatings carry one — and so do belts and cables.

That last line matters more on a dual-function frame than a single one. The HD-3400 runs on a single cable, 135⅛ inches long, and that one cable serves both exercises. Hoist's own maintenance schedule does not treat cable replacement as a repair; it lists replacement as a routine item, alongside inspecting for fraying, cracking, peeling or discolouration and pulling the machine from service until a worn cable is changed.

Choose the HD-3400 if you will service it on the schedule your room demands, not the one printed on the decal.

That is not a figure of speech. Hoist publishes two maintenance schedules — one for commercial and light-commercial rooms, one for home use — and every machine ships wearing the commercial decal. Home owners are told in the manual to follow the home schedule instead.

Confirm the warranty column that applies to your room before the order goes in, because the terms are not identical across use types. The warranty runs to the original purchaser only and covers defects in workmanship and materials under normal use or service; manufacturer defects are the only thing in scope, and Hoist reserves the right to change specifications, design and function. Complete warranty information sits in Hoist's own support documentation.

Key Features

✅ Switch exercises without leaving the seat

✅ Load changes take seconds between sets

✅ One setup number repeats for regular users

✅ Fewer setup steps for a busy queue

✅ Heavier build available for stronger lifters

✅ Smaller weight step for careful progression

✅ Anchored frame stays steady under load

✅ Hand grips steady the torso through reps

✅ Rubber feet protect the floor surface

✅ Wipe-down upholstery suits shared training

✅ Service schedule published for every part

✅ Parts ordered by model and serial number

Full Specifications

Both builds accept an optional 5 lbs. weight upgrade, part code RS-CAGE-NG-OPT3, which is what the add-on figures below reflect.

Size and clearance

• Product Length — 60.75" (154 cm)
• Product Width — 48.75" (124 cm)
• Product Height — 55.00" (140 cm)

Standard HD build

• Machine Weight — 557 lbs. (253 kg)
• Weight Stack — 215 lbs. (98 kg)
• Machine Weight with add-on — 569 lbs. (258 kg)
• Weight Stack with add-on — 220 lbs. (100 kg)

Heavy stack HDG build

• Machine Weight — 580 lbs. (263 kg)
• Weight Stack — 240 lbs. (109 kg)
• Machine Weight with add-on — 592 lbs. (267 kg)
• Weight Stack with add-on — 245 lbs. (111 kg)

Delivery, Assembly and Floor Space

Assembly takes two people and finishes with a squareness check to confirm the frame sits true.

Hoist specifies a ratchet wrench with half-inch, nine-sixteenths and three-quarter-inch sockets, an adjustable wrench, a rubber mallet, a tape measure, a level and a hex key set. The frame then bolts to the exercise floor using minimum four-and-a-half-inch bolts, and Hoist is blunt about why: an unanchored frame can tip, with serious injury or death in the warning.

How much floor space does a leg extension machine need? Plan the footprint above plus clear room to step in and out of the seat and let the roller travel through its arc. Add drilling access as well, because anchoring makes the position permanent — this is a one-time placement decision, not a piece you shuffle around a room.

Hamilton Home Fitness ships nationwide from Tennessee. Review the shipping and returns terms before ordering, and larger fit-outs can begin with a gym design consultation so the frame lands in the right spot first time.

A good fit if:

• One floor position must cover both movements
• Several users share the station each day
• The floor can take permanent anchors
• You prefer a fixed stack to loading plates

Look elsewhere if:

• Your program calls for a prone leg curl
• You need a published maximum user weight
• You need crate sizes before delivery day
• You want progression beyond the heavy stack

The prone-curl point is the one that sends buyers elsewhere most often. Curls on this frame are performed seated with the back supported, which keeps the hip flexed throughout. If your programming specifically calls for the hip-extended version, the Hoist prone leg curl RS-2408 is the correct frame instead.

How It Compares on This Site

Three routes cover most leg extension buyers here, and price alone will not tell you which one belongs on your floor. The dedicated Hoist Leg Extension RS-2401 and the wider range of leg extension machines both sit alongside this model.

Hoist HD-3400

• Exercises — Extension and curl
• Price — $3,960.00
• Loading — Pin-selected weight stack
• Suits — One frame covering both

Hoist Leg Extension RS-2401

• Exercises — Extension only
• Price — $5,226.00
• Loading — Roc-It selectorized stack
• Suits — Extensions running continuously

Body-Solid S2LEX Series 2

• Exercises — Extension only
• Price — $2,195.00
• Loading — Selectorized, 160 lb stack
• Suits — Budget leading the decision

Weigh those three against your floor, then choose the one that earns the space.

Common Buyer Questions

Does the number on the stack equal the weight you lift?

No. Hoist's owner's manual publishes a weight-ratio chart showing the leg extension delivering 85% of the selected stack and the leg curl 57%. Plenty of competing combos advertise a straight 1:1 ratio, so compare your working weights against those percentages rather than the stack total.

Is there a maximum user weight?

Hoist does not publish one for this machine — not in the spec sheet, the owner's manual or the product listing. If a stated user weight limit is a requirement for your facility, ask before ordering rather than assuming a number.

What are the crate dimensions for delivery?

Hoist does not publish crate sizes for the HD-3400. Measure doorways, lifts and turns, then confirm freight dimensions with the team before the truck is booked.

Why is HOIST sold under private invoice only?

HOIST is listed here as private invoice only, so the order completes directly with our team rather than through standard checkout. That also makes it simple to confirm the stack build and lead time before anything ships.

What happens if the stack build turns out wrong?

A 30-day return window applies to undamaged equipment in its original packaging, with a restocking fee and return shipping payable by the buyer. Equipment used beyond testing is not eligible, so settle the build question before the first session rather than after.

What does Hoist need to process a warranty claim?

Model number, serial number, date of installation and any information supporting the defect. Record the serial number in the manual at assembly and register the warranty with Hoist at that point — chasing it later is the part owners find painful.

Ready to move? Talk to the team, confirm your build, and get the HD-3400 on order with Hamilton Home Fitness — shipped nationwide from Tennessee, with the spec checked before it leaves.

Manual

Brochure

Spec Sheet