Guide · Rack pins, band pegs and small hardware
When an attachment's locking pin does not line up
If a J-cup, spotter arm or other attachment cannot take its locking pin as the maker shows, it is not installed. Why it happens and what to ask the maker.
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Short answer
Stop and do not use it. An attachment whose locking pin cannot be installed the way the maker shows is not installed. Take it off the rack and ask the attachment maker whether your rack is a listed host. Never drill, file, bend or ream anything, and never leave the pin out.
Why it happens
Many attachments hang on one pin and lock with a second pin, a hitch pin or a tab that must land in another hole. That second point is built for a set distance. If your rack's hole pitch is different, the second point misses.
Some examples of attachments that rely on more than one pin, from their makers:
- Titan states 200 mm between the centers of the two pins on its T-2 spotter arms (T2SA, SKU 401090).[1]
- Titan's T-3 strap spotter arms lock with two hitch pins per arm and fit racks with 2x3 in uprights and 11/16 in holes.[2]
- Rogue's Monster Safety Spotter Arms 2.0 are secured with a pin through the arm and upright after the arm's mounting pin is rotated down, one pin per arm as shown in the manual.[3]
And racks use different pitches:
| Rack | Front spacing the maker lists |
|---|---|
| Titan T-2 | 2 in on center[4], with some sections measuring 1 in[1] |
| REP PR-1000 | 2 in[5] |
| REP PR-1100 | 3 in[5] |
An attachment built around one of these patterns can hang on the other but fail to lock.
The documented case
Garage Gym Experiment reported that Titan T-2 accessories relying on lock-in pins did not fully work on a REP PR-1100: roller J-cups fit, but their lock-in pins could not be used as intended.[6] Dip bars without lock-in pins worked in that comparison. This is one reviewer's report on specific racks, not a rule for every pairing. Our rule does not change: if the required lock cannot be installed, the attachment is not installed.
It can happen within one brand
Same maker does not mean same pattern. Titan states that its T-2 Series Adjustable Monolift Attachments are not compatible with T-2 Series Power Racks made before October 2020.[7] Check the rack year as well as the model; our guide to identifying your rack shows where to find it.
What to ask the maker
Send the attachment maker:
- Your rack's maker, model and purchase year.
- The upright size, hole diameter and hole spacing in the zone you are using. Our measuring guide shows how.
- Photos of the attachment on the rack with the pin that will not go in, and a ruler across the holes.
- The attachment's model or SKU and where you bought it.
Ask one question: "Is this attachment listed for my rack, and if so, how should the lock be installed?" If the answer is no, return or exchange it for the version made for your rack.
Why makers will not promise cross-brand fit
REP states it cannot guarantee compatibility between REP items and non-REP items because of manufacturing and machining differences.[8] Its warranty page adds that REP does not guarantee compatibility with other companies' products and that warranties can be voided in those cases.[9] The safe source of fit is the attachment maker's host list for your exact rack.
Next
Questions
My J-cup's lock pin misses the hole. Is it safe to use?
Treat it as not installed. Take it off the rack and contact the attachment maker with your rack model, year and hole spacing.
Can I drill a new hole?
No. Do not drill, file, bend or ream the rack or the attachment, and do not leave the pin out. REP says products modified outside REP lose warranty coverage, and the lock exists for a reason.[9]
Why do Titan parts not lock on my REP rack?
Titan lists T-2 holes at 2 in on center and REP lists the PR-1100 at 3 in, so a part built for one pitch can miss on the other. Garage Gym Experiment reported that T-2 accessories relying on lock-in pins did not fully work on a PR-1100.[4][5][6]
Does the rack maker guarantee other brands' parts?
REP says it does not guarantee compatibility with other companies' products and that warranties can be voided in those cases.[9]