When you start running out of plates or stack, you’ve got two options: stop progressing, or cheat the machine.
GymPin exists so you never have to choose.
In this Q&A, Ben answers the questions we get every day – from KingPin vs GymPin vs Mini Pin, to internal vs external machine extenders, Light vs Pro D handles, which tricep rope to buy, and why our seat belt becomes non-negotiable on heavy leg day.
Use this guide to work out exactly which GymPin kit you need for your machines and your style of training.
This article breaks everything down into simple, clear answers so you can choose the right GymPin equipment for your goals.
Why the KingPin Only Comes in 10mm
The KingPin was designed to live a hard life. Heavy stacks, heavy abuse, no excuses – especially on stubborn lower-body machines like heavy adductors.
To do that safely, it has to be thick.
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KingPin: 10mm only – built for serious loads
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GymPin & Mini Pin: available in both 8mm and 10mm
An 8mm KingPin simply wouldn’t be strong enough for what people use it for. If your machine takes an 8mm selector, grab the GymPin 8mm or Mini Pin 8mm and you’ll get the strength you need in the right diameter.
https://gym-pin.co.uk/collections/gympins/products/thekingpin
Internal vs External Machine Extenders
When you’ve got more strength than the machine has plate space, that’s where machine extenders come in.
Internal Machine Extenders
Internal extenders are designed to slide inside the plate-loaded sleeve.
They’re ideal if you’re training on:
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Hammer Strength plate-loaded machines
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Machines where you or your members are already maxing the stack
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Set-ups where the end caps do come off
If the end caps unscrew or pull off, internal extenders will slot straight in and instantly give you more loading room.
External Machine Extenders
If the machine has fixed / non-removable end caps or a completely closed end, you’ll need external extenders instead.
They are:
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Made from welded steel
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Finished in textured black
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Perfect for leg presses, hack squats and other closed-end plate-loaded machines
In short:
| Machine end | Extender to use |
|---|---|
| End caps come off | Internal Machine Extenders |
| End caps don’t come off / closed end | External Machine Extenders |
Pick the extender based on your machine, and you’ll never run out of loading space again.
Light vs Pro D Handle Bars
We offer two versions of our popular D-handle bars: Light and Pro.
Light Range
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Made from laser-cut steel
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8mm thick
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Square 90° ends
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Budget-friendly
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Perfect for everyday cable work
Pro Range
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10mm thick steel
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Chamfered, smoothed, premium edges
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Fully polished holes and edges
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Available in textured black or raw stainless steel
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Rated to 150kg
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Built for heavy rows and serious lifters
If you want the best feel, grip, and finish — the Pro Range is the one.
Using the Mini Pin for Incremental Loading
The Mini Pin was created for lifters who find the jump between stack plates too big — especially for curls, triceps extensions and single-joint work.
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Mini Pin loadable space: 3 inches
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GymPin loadable space: 6 inches
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KingPin loadable space: 8 inches
It’s perfect for:
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Adding 1.25kg or 2.5kg plates
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Breaking past sticking points
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Microloading the stack in precise rep ranges
Weights of each pin:
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Mini Pin: ~500g
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GymPin: ~800g
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KingPin: ~1.1kg
They can even be used as add-on weight by themselves.
Raw vs Polished Finish
Raw Finish
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Mottled raw aluminium
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Machined for a subtle, dull, industrial look
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Minimal shine — premium functional style
Polished Finish
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Hand-polished by the team in-house
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High shine
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Maximum “wow” factor when you open the box
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Our most premium aesthetic option
Both perform identically. The choice is purely visual.
Which Tricep Rope Should You Buy?
GymPin currently offers three tricep rope options:
1.4m Double-Length Rope (Buy Here)
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The solution to cramped, short gym ropes
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Allows full extension and full contraction
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Eliminates uncomfortable internal shoulder rotation
Ergo Ropes (Most Popular) (Buy Here)
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Ergonomic contoured handles
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Rounded ends that sit perfectly in the palm
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Incredible tricep pushdown feel
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Constantly in use at commercial gyms
HD Ropes
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Partnership with HD Gym Equipment
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Loop ends allow supinated, pronated, or neutral grip variations
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Around 1.5m long
Recommendation: If budget allows, the Erggo Ropes offer the best overall experience.
Seat Belt Length & Why It's a Best Seller
If you’ve ever hit a heavy set of leg extensions and felt yourself physically lifting off the seat, you already know why our seat belt is such a game changer.
It fixes one of the most annoying problems in strength training:
The stack gets heavier, but your body starts fighting you instead of the weight.
Once you crank the seat belt around the base of the machine:
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your hips are locked in,
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your body stops shifting,
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and all your effort goes exactly where it should — into your quads or hamstrings.
It’s one of those accessories you don’t think you need…
until you train without it one day and instantly regret it.
Stats:
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Length: 1.7m (one size fits all)
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Fits every machine we’ve tested
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Rolls up small enough to live in your gym bag
What Size Pin Do You Need? (8mm or 10mm)
Most gym machines use either an 8mm or 10mm selector pin — and if you pick the wrong size, it won’t even fit in the stack.
To make it easy, we’ve put a brand chart on the GymPin website, but here are the quick rules lifters usually recognise:
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Matrix: could be 8mm or 10mm depending on the year
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Precor: also mixed
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Life Fitness: mostly 10mm
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Life Fitness Insignia: 8mm (the one that catches people out)
If you’re unsure, there’s a simple hack every lifter can do in 10 seconds:
Measure the diameter of the pin already in the machine.
It will be either 8mm or 10mm, no exceptions.
If you still aren’t sure, DM us a photo — we answer this question all day, every day.
How Many Plates Fit on a GymPin or KingPin?
Everyone wants to know the same thing:
“How many plates can I actually get on this thing?”
Here’s the truth:
It depends entirely on your plates.
Some gyms have thin steels, others have chunky rubber bumpers.
But as a rule of thumb:
| Pin | Loadable Space | Typical Plate Capacity |
|---|---|---|
| Mini Pin | 3 inches | 1 plate |
| GymPin | 6 inches | ~3 plates |
| KingPin | 8 inches | ~4 plates |
Some users fit even more depending on plate thickness.
See the GymPin Cable Stack Extender Size Guide
Joining the GymPin Athlete Team
Yes — we're always open to adding new athletes worldwide.
Head to:
Partners → Affiliates
on the website to apply for your own personalised GymPin code.