Buying task · Measuring and buying
Before you buy: measure your rack, read the rating, check the seller
Identify your rack, measure upright size, hole diameter and spacing, match the attachment maker's list, read the rating's scope, then check the seller and returns.
We may earn a commission if you buy through links on this page. How we make money
Short answer
Identify your rack system, measure its upright size, hole diameter and hole spacing, and buy only an attachment whose maker lists your rack or those exact numbers. Then read the rating in the maker's own scope and check who actually sells the listing. A matching tube size is not proof of fit: REP says it cannot guarantee its parts fit other brands' racks.[1]
Why measuring comes first
Rack attachments fit by three independent numbers: the upright's outside size, the hole diameter and the hole spacing. Pin size and position, and the rack's inside depth for parts that span it, come next. Two racks can share one number and differ on the others.
Labels make this harder, because nominal sizes look alike. One inch is exactly 25.4 mm,[2] so a 2x2 in upright works out to 50.8 mm, not the same size as a 50 mm metric tube.[2] A 3x3 in upright is 76.2 mm, 1.2 mm larger per side than a 75 mm tube.[2] A 60 mm tube is about 2.362 in, which Bells of Steel labels 2.3 in[3] and Force USA labels 2.4 in.[4] Those are calculations, never fit tolerances.
The decisions, in order
1. Identify the rack. Find the maker, the line and, where it matters, the version or year. The identify-your-rack guide shows where to look, and the fit finder lists what each maker publishes for 20 rack systems.
2. Measure the three numbers. Use a caliper or a good tape on the outside of the tube, the hole and the distance between hole centers. The measuring guide walks through each one, the tubing guide covers near-miss sizes, and the hole spacing guide explains Westside and uniform patterns. If you only know the tube, start with the upright size finder.
3. Match the attachment maker's host list. REP states it cannot guarantee compatibility between REP items and non-REP items because of manufacturing and machining differences.[5] Read the list the attachment maker gives; never widen it.
4. Read the rating's scope. A rating per pair, per peg, combined, rackable or as a drop capacity are different statements. Quote each the way the maker writes it. The load ratings guide explains the terms. For general-use products subject to consumer product safety rules, the CPSC says a manufacturer or importer must issue a General Certificate of Conformity;[6] that rule does not tell you any one attachment's rating.
5. Check the seller, returns and warranty. US Customs and Border Protection says about 87% of counterfeit seizures occur in small packages and advises shopping from authenticated online sources.[7] Amazon's US policy lets most items be returned within 30 days of delivery, with eligibility shown on each product page,[8] and items shipped by third-party sellers go back to that seller.[8] REP says warranties can be voided when its products are used with other companies' products.[9] The online buying checklist and the warranties guide go through each step.
How to choose
Do steps 1 and 2 before you open a product page. When an attachment comes in several sizes, the measurement picks the variant. Synergee is an example: its J-cups come in 2x2, 2x3 and 3x3 versions with a converter for 5/8 in or 1 in holes,[10] and its safety straps come in 23, 29 and 35 in inside-depth options.[11] Synergee's own J-cup page links its Amazon store in the US and Canada.[10]
Picks that fit2 products
Synergee J-cups: choose your measured upright (2x2, 2x3 or 3x3) and, for 1 in holes, a version with the 5/8 in / 1 in converter.
More on choosing
Synergee safety straps: choose your upright and the option closest to your measured inside depth (23, 29 or 35 in; 2x2 in 23 in only). On Amazon, check that 'Ships from / Sold by' shows Amazon.com or Synergee.
Choose Synergee if your rack is not on any maker's named list
Synergee J-Cups, pair (2x2, 2x3 or 3x3; 5/8 in or 1 in converter)
Straps sold by upright size and inside depth
Synergee Safety Straps, pair (2x2, 2x3 or 3x3; 23, 29 or 35 in inside depth)
Every page on measuring and buying
Guides
- Identify your rack before buying any attachment
- How to measure your rack's uprights, holes and spacing
- 2x2 vs 50 mm, 3x3 vs 75 mm and 60 mm rack tubing
- Westside vs 2-inch vs metric hole spacing
- Bolt-down, flat-foot and folding racks: what the maker says
- Attachments for mixed racks: a studio inventory by rack system
- Buying rack attachments on Amazon or AliExpress: what to check first
- Rack attachment warranties and returns by maker
Tools
- Rack attachment fit finder: pick your rack system
- Upright size finder: 2x2, 2x3, 3x3, 60 mm or 75 mm
Upright sizes
Rack systems
- Rogue: Infinity and R-Series, Monster Lite, SML-2, RML-390F Flat Foot, Monster
- REP: PR-1000 and PR-1050, PR-1100, PR-4000, PR-5000
- Titan: T-2, T-3, X-3, TITAN Series
- Bells of Steel: 60 mm racks, Hydra, Manticore
- PRx: Profile ONE, PRO and CORE
- Force USA: MyRack
- Powertec: power racks and half racks
- Sunny Health & Fitness: Power Zone racks
Key terms
Nominal size, caliper, center-to-center spacing, fit attributes, cross-brand fit, seller of record, counterfeit and original purchaser.
Everything in this topic
Guides
- 2x2 vs 50 mm, 3x3 vs 75 mm and 60 mm rack tubingHelps you tell whether your rack is imperial or metric tubing and why that matters for attachments.
- Attachments for mixed racks: a studio inventory by rack systemHelps a coach or studio owner track which attachments fit which rack and buy by each rack's record.
- Bolt-down, flat-foot and folding racks: what the maker says before you add attachmentsHelps a rack owner find the rack maker's anchoring instruction and exclusions before adding a front or outside attachment.
- Buying rack attachments on Amazon or AliExpress: what to check firstHelps you check a marketplace listing for a rack attachment before you order: right variant, real seller, workable returns.
- How to measure your rack's uprights, holes and spacingHelps you record your rack's upright size, hole diameter and hole spacing correctly before you buy an attachment.
- Identify your rack before buying any attachmentHelps you pin down the exact rack model, year and published specs before you choose any attachment.
- Rack attachment warranties and returns by makerShows what each maker's warranty covers for rack attachments and pins, and who it covers, before you choose where to buy.
- Westside vs 2-inch vs metric hole spacingHelps you identify your rack's hole pattern and know when it matters for an attachment.
Tools
- Rack attachment fit finderShows what your rack maker publishes about its fit numbers and attachments, so you can match an attachment to your exact rack.
- Upright size finderTurns your measured upright size into the hole and pin sizes makers list for it and the rack systems that use it, without treating conversions as fit.
Common questions
Will 75 mm J-cups fit my 3x3 rack?
Not on the strength of the label. 3x3 in works out to 76.2 mm, 1.2 mm per side larger than 75 mm. Only the attachment maker's host list or stated upright size can answer it. More in 2x2 vs 50 mm, 3x3 vs 75 mm and 60 mm rack tubing
Is 60 mm the same as 2.4 in?
60 mm is about 2.362 in. Force USA labels its 60 mm MyRack tubing 2.4 in, while Bells of Steel labels its 60 mm tubing 2.3 in. Both are rounded labels for the same metric size. More in 2x2 vs 50 mm, 3x3 vs 75 mm and 60 mm rack tubing
Is 2x2 the same as 50 mm?
No. A 2x2 in upright works out to 50.8 x 50.8 mm, which is not the same size as a 50 x 50 mm metric tube. More in 2x2 vs 50 mm, 3x3 vs 75 mm and 60 mm rack tubing
Do Bells of Steel J-cups fit other brands' 3x3 racks?
Bells of Steel says the Hydra version of its standard J-cups fits non-Bells of Steel racks with true 3 x 3 in uprights and 5/8 in holes. Both conditions apply; measure before relying on it. More in 2x2 vs 50 mm, 3x3 vs 75 mm and 60 mm rack tubing
Can I standardize attachments across different rack brands?
Rarely. REP says it cannot guarantee compatibility with non-REP items, and an independent reviewer reported that Titan T-2 lock-in pins could not be used as intended on a REP PR-1100. Buy per rack, by each maker's host list. More in Attachments for mixed racks: a studio inventory by rack system
How do I keep track of which J-cups fit which rack?
Keep one record per rack with its model, year, upright size, hole diameter, hole spacing, pin class and the attachments whose makers list it, and label each attachment with its rack. More in Attachments for mixed racks: a studio inventory by rack system
Do Bells of Steel attachments work across its racks?
Bells of Steel says Hydra attachments fit Manticore racks through the keyholes, though they may lift slightly when pushed upward, and calls Manticore parts on a Manticore rack the most stable fit. That covers Bells of Steel racks only. More in Attachments for mixed racks: a studio inventory by rack system
Do attachments for one Titan rack fit an older rack of the same series?
Not always. Titan says its T-2 Adjustable Monolift Attachments do not fit T-2 racks made before October 2020. More in Attachments for mixed racks: a studio inventory by rack system
Questions
How do I know an attachment fits my rack?
When the attachment maker names your rack, or states your exact upright size, hole size and spacing. REP, for example, says it cannot guarantee its parts fit non-REP racks because of machining differences, so a matching tube size alone is not proof.[5]
Is 3x3 the same as 75 mm?
No. A 3x3 in upright works out to 76.2 x 76.2 mm, which is 1.2 mm larger per side than a 75 x 75 mm tube. That is a calculation from the exact inch, not a fit tolerance.[2]
Are Amazon rack attachments genuine?
Check who sells and ships each listing. US Customs and Border Protection says about 87% of counterfeit seizures occur in small packages and advises shopping from authenticated online sources; a brand's own page linking a store is the clearest sign.[7]
Will a third-party attachment void my warranty?
It can, depending on the rack maker. REP says it does not guarantee compatibility with other companies' products and that warranties can be voided in those cases. Read your rack maker's warranty before mixing brands.[9]