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Hoist Fitness Pec Fly/Rear Delt HD-3900
Hoist HD-3900 Pec Fly and Rear Delt Machine
The Hoist HD-3900 is a selectorized pec fly machine that trains rear delts from the same frame. One weight stack drives both movements, and the exercise arms adjust so each user sets their own path. It suits studios, clubs, and serious home gyms that want two upper-body angles from one station.
- Assembled footprint — 66.50" L x 55.50" W (169 x 141 cm)
- Frame height—77.75" (198 cm)
- Machine weight—649 lbs. (294 kg)
- Seat adjustments—seven, numbered 1–7
- Arm pivots—dual on each arm
- Application—commercial and light commercial
- Best fit—two angles, one station
What This Pec Fly Machine Trains
This station covers a horizontal push and a horizontal pull without the chest and back fighting over the same handles. Bring the arms together and the pectorals do the closing work on their own, with no triceps and no pressing. Open them in the other direction and the load moves to the rear deltoids and the muscles between the shoulder blades.
What muscles does a pec fly machine work? The fly drives the pectoralis major, with the front deltoids assisting near the finish. The reverse direction shifts that to the posterior deltoids, rhomboids and mid-trapezius. That pairing is the reason dual-function frames exist at all: most training programs run heavy on pressing and light on pulling, and one machine closes the gap without a second purchase.
Where this sits in the range matters too. The HD-3900 is an isolation station, not a press, so it earns its floor space next to a pressing machine rather than instead of one. If pressing is the missing piece, the chest and shoulder machines collection covers that side.
The Changeover Nobody Explains
Switching between the two exercises is a repositioning, not a seat tweak — and almost no listing says so.
Here is the evidence. The HD-3900's own parts list includes a chest pad assembly, which is what you brace against for the reverse direction. Separately, Hoist markets a different model, the Club Line CL-3309, as the first machine ever to offer both exercises facing the same direction. Read those two facts together, and the picture is clear: on a conventional dual-function frame, the second exercise means getting up and turning around.
How do you switch from pec fly to rear delt? You leave the seat, reverse your body position, and reset the seat height for the new contact point. The stack stays where it is; you move.
That has a consequence buyers only discover after delivery. The seat height that puts the handles at chest level for the fly is not automatically the height that puts the pad on your sternum for the reverse fly. Seven numbered positions exist precisely because one setting cannot serve both directions. Note both numbers during your first session, and every session after that is fast.
Choose the HD-3900 when you want the larger stack and will log two seat numbers; choose a same-direction frame when a two-second switch matters more than resistance.
Key Features
✅ Two upper-body angles from one footprint
✅ Swiveling grips let wrists find their line.
✅ Dual pivots per arm follow your own path.
✅ Range-of-motion set separately per exercise
✅ Numbered seat stops make setups repeatable.
✅ Threaded stops keep both arms level.
✅ Caged weight stack on Hoist's shared platform
✅ Optional upgrade lifts the stack ceiling.
✅ Pin changes take seconds between sets.
✅ Chest pad braces the reverse-fly direction.
✅ Leveling foot squares and uneven floor spots
✅ Separate home and club care schedules
Hoist Sells This Move Three Ways
Hoist builds this movement across three lines at three price points, and the cheapest one carries the biggest stack. That is worth knowing before you assume the premium badge buys more resistance.
Is a dual-function machine worth it? It is when floor space is finite and both movements get trained. It is not when the station only ever sees flies, because a dedicated frame gives a cleaner setup with nothing to reverse. The Roc-It Pec Fly RS-2302 is the dedicated option here.
HD-3900 Pec Fly / Rear Delt
- Hoist line — HD Dual Series
- Movements—pec fly and rear delt
- Stack — 310 lbs. (141 kg)
- List price — $3,960.00
- Pick it when resistance and value lead
Club Line CL-3309
- Hoist line—Club Line
- Movements—pec fly and rear delt
- Stack—200 lbs. (91 kg)
- List price—$4,840.00
- Pick it when same-direction switching wins
Roc-It Pec Fly RS-2302
- Hoist line—Roc-It Selectorized
- Movements — pec fly only
- Stack — 255 lbs. (116 kg)
- List price — $5,226.00
- Pick it when — flyes are the only job
Nothing above is a knock on the pricier frames; they buy different things. Browse the full selectorized chest and shoulder line to see where each one sits.
Full Specifications
Every figure below comes from the HD-3900 specification sheet and owner's manual published by Hoist.
Build and Resistance
- Stack upgrade part — RS-CAGE-NG-OPT1, 5 lbs.
- Machine weight with add-on — 661 lbs. (300 kg)
- Weight stack with add-on—315 lbs. (143 kg)
- Stack build—Hoist WS#12, 20 lb top weight
Movement and Adjustment
- Hand grips—swiveling with rotating grips
- Range of motion—adjustable for both exercises
- Arm levelling—threaded stop and jam nut
Setup and Ownership
- Anchoring—minimum 4 1/2" floor bolts
- Assembly—two people plus hand tools
- SKU—HD-3900
- Ordering—HOIST private invoice only
- Warranty—original purchaser only
Ready to price it for your floor? Request pricing on the HD-3900 and we will confirm freight and lead time for your address.
Who It Fits and Who Should Skip
A good fit if:
- You train chest and upper back in one session
- Your stack needs headroom past a 200 lb ceiling
- The station has a permanent floor position
- Two movements per footprint beats two machines
Look elsewhere if:
- Circuit speed matters more than load
- The floor cannot be drilled for anchor bolts
- Overhead or under-beam clearance runs tight
- You will only ever perform the fly
That last point deserves honesty rather than a soft sell. Buyers' training flyes alone are better served by a dedicated frame, and buyers who mostly press should look at the Hoist Chest/Shoulder Press HD-3300 first. If budget is the constraint rather than movement, the BodyKore GR633 Pectoral Fly/Rear Delt covers the same pairing at a lower entry point.
Ordering, Delivery, and Warranty
Hoist runs on private invoice, so the HD-3900 is quoted rather than checked out like a small accessory. Hamilton Home Fitness is an authorized Hoist dealer based in Tennessee, shipping to all 50 states by freight.
Hoist warrants the product to the original purchaser only, against defects in workmanship and materials under normal use or service. Coverage applies to manufacturer defects, and complete terms sit under the Support link. Hoist also reserves the right to change specifications, design, and function at any time, which is worth remembering if you are matching a second unit to one already on your floor.
Plan the room before the freight arrives. A 649 lb frame is not repositioned casually, and the anchor points are permanent. Full terms are on the shipping and returns page, including the 30-day window and the condition requirements that come with it.
Pec Fly Machine Questions
Is this a pec deck or a chest fly machine?
Both names describe the same seated movement, and retailers use them interchangeably. The practical difference is whether the arms reverse for upper-back work. This one does.
How much resistance reaches each handle?
Hoist publishes a weight ratio chart in the owner's manual showing roughly 20% of the selected stack per handle, which works out to 62 lbs. per handle at the top setting. Ratios differ between manufacturers, so judge the machine by how it moves rather than by the number on the plate.
Can one person assemble the HD-3900?
No. Hoist specifies two people plus hand tools, and the manual includes a squareness check once the frame is together. Budget an afternoon and a second set of hands.
What user weight limit does Hoist publish?
None. No user weight limit appears in the specification sheet, the owner's manual or the product listing. We would rather say that plainly than repeat a figure from somewhere else.
Is the optional 5 lb upgrade worth adding?
It is worth adding at order time rather than later, because retrofitting means opening the stack cage again. It suits shared floors where lifters want a smaller jump near their working weight.
Can I return it if it does not fit the room?
Returns run on a 30-day window with the equipment undamaged and back in original packaging, and a restocking fee applies. Measure the doorway, the ceiling and the anchor position before you order, since a machine built on site is no longer boxed.
Two movements, one stack, one footprint. Put the HD-3900 on your floor with a quote built around your delivery access and layout, or book a gym design and we will plan the station placement with the rest of the room.
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