If you're shopping for a cable functional trainer and keep seeing both single-stack and dual-stack versions of the same rack attachment, you're not imagining things — the single vs dual stack functional trainer decision is one of the more consequential choices in a home or small commercial gym, because it determines whether two people can train on the unit at once.
Body-Solid's GPRFT and SPRFTS functional trainer attachments are a good real-world example of the tradeoff: same rack-mounted cable concept, very different capability and price.
What "Single vs Dual Stack" Actually Means
A single-stack functional trainer has one weight resistance source feeding the cable arms, so only one person effectively drives the machine at a time. A dual-stack unit gives each side its own independent weight stack, which means two people can use opposite sides of the same frame simultaneously, each with their own weight selection.
GPRFT Functional Trainer Attachment (Single)
Price: $1,495 | Weight Capacity: 600 lbs. | Product Weight: 190 lbs. | Footprint: 77"L x 74"W x 81.25"H
The GPRFT Functional Trainer Attachment is Body-Solid's single-unit rack-mounted functional trainer, rated to a 600 lb. weight capacity. It's designed to bolt onto a compatible power rack rather than stand alone, which keeps its footprint and price down compared to a full dual-stack station. For a single user working through cable exercises like presses, rows, and cable crossovers, the GPRFT covers the movement patterns without the cost of a second independent weight stack.
Best for: Single-user home gyms or spaces where only one person trains on the cable station at a time.
SPRFTS Functional Trainer Attachment (Dual)
Price: $4,250 | Dual 210 lb. Weight Stacks (upgradable to 310 lb.) | Product Weight: 672 lbs. | Dimensions: 91"L x 58"W x 92"H
The SPRFTS Functional Trainer Attachment steps up to two independent 210 lb. weight stacks, upgradable to 310 lb. each, so two lifters can select completely different resistance and train both sides of the frame at the same time. That independence is the entire value proposition of a dual-stack machine — it's not just "more weight," it's simultaneous, separate use. At 672 lbs. product weight and a 91"L x 58"W x 92"H footprint, it's also a substantially bigger commitment of both space and budget than the single-stack GPRFT.
Best for: Shared home gyms, small studios, or facilities where more than one person needs to train on the functional trainer at once.
Single vs Dual Stack: Which Should You Buy?
The decision mostly comes down to how many people will realistically use the machine at the same time, plus your budget and space. At $1,495, the GPRFT is roughly a third of the SPRFTS's $4,250 price and needs a smaller footprint, making it the more practical choice if you're the only one training or if your household or gym members are willing to take turns. The SPRFTS costs more and takes up considerably more floor space, but the dual 210 lb. stacks (upgradable to 310 lb.) mean two people never have to wait on each other or compromise on resistance.
It's also worth thinking about upgrade paths: because the SPRFTS ships with dual stacks that are individually upgradable to 310 lb., it has more built-in headroom to grow with a lifter's strength than a single-stack unit capped at its rated capacity.
Rack Attachment Considerations
Both the GPRFT and SPRFTS are listed as rack attachments, not standalone machines — they're designed to bolt onto a compatible power rack rather than free-stand on their own. If you don't already own a compatible rack, factor that into your total cost and footprint planning before comparing GPRFT and SPRFTS pricing side by side.
Best Functional Trainer for a Shared Home Gym
If more than one person in your household trains regularly — especially at different times or different strength levels — the dual-stack SPRFTS removes the single biggest friction point of a shared cable station: waiting for the other person to finish, or fighting over the same pin-loaded weight. For a single dedicated lifter, that flexibility is nice to have but not worth the roughly $2,750 price gap over the GPRFT.
Why Buy From Everything Gyms?
As an authorized Body-Solid dealer, Everything Gyms ships every functional trainer attachment straight from Body-Solid's warehouse near Chicago, with free nationwide shipping, a price match guarantee, and the full Body-Solid manufacturer warranty backing your purchase.
Frequently Asked Questions
What are the benefits of a dual stack functional trainer?
A dual-stack trainer like the SPRFTS gives two users independent weight stacks, so both sides of the machine can be used at the same time with different resistance selected for each person.
How many weight stacks does a functional trainer need?
It depends on how many people use it. A single stack, like the GPRFT, is enough for one primary user. Two or more regular users benefit from a dual-stack unit like the SPRFTS so nobody has to wait.
What's the difference between the GPRFT and SPRFTS?
The GPRFT is Body-Solid's single-unit functional trainer attachment rated to 600 lbs., priced at $1,495. The SPRFTS adds two independent 210 lb. weight stacks (upgradable to 310 lb.) for simultaneous two-person use, priced at $4,250.
What's the best functional trainer for a shared home gym?
For households or small facilities with more than one regular user, the dual-stack SPRFTS is the better fit since it lets two people train at once without sharing a single weight source.
Do I need a power rack to use these attachments?
Yes — both the GPRFT and SPRFTS are rack attachments designed to bolt onto a compatible Body-Solid power rack rather than stand alone.
Find Your Functional Trainer
Whether you need the space-saving GPRFT single-stack attachment or the two-person SPRFTS dual-stack attachment, Everything Gyms has both ready to ship from Body-Solid's warehouse.