Product Features
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BUILD 3D DELTS
Ditch the dumbbells and get more out of every rep! The smartly positioned weight horns increase tension at the bottom, where dumbbells fall short, targeting your delts more effectively. Perform lateral raises, single-arm front raises and rear delt flies to leave no delt undone on this full-shoulder solution!
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UNLOCK CHEST FLIES
On dumbbell chest flies, your biceps steal the show and pushing to failure feels more like gambling than training. But thanks to the Shoulder Boulder’s design, that sweet burn stays focused on your chest muscles. Plus, the 360° dial sets the ideal starting position AND acts as a safety catch—because your pecs deserve better odds than the roulette table.
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COMPACT SHOULDER & CHEST STATION
Why let a bulky machine take over your home gym? The Shoulder Boulder Lateral Raise Attachment mounts directly to your power rack and occupies a fraction of the footprint of a rear delt/chest-fly machine. This keeps your Castle of Gainz clutter-free; after all, the best gym is one you can actually walk through.
Product Details
Build boulder shoulders and poppin’ pecs for that iconic V-taper look!
Dumbbell shoulder and chest isolations suffer from inconsistent resistance, but the Shoulder Boulder’s design provides smooth, controlled movement with a superior resistance profile.
A standalone rear delt/chest fly station takes up a whopping 5-foot x 5-foot footprint (or more), while this rack attachment mounts to your rack to save space. Easily adjust its height on your power rack for the ideal fit.
This nifty unit uses weight plates, saving you money. Plus, easily micro-load the smaller muscles of your shoulders to minimize injury and get better gains!
While it doesn’t beat a cable machine for chest flies, the Shoulder Boulder comes in as a close second. Set it low & wheel over a bench (or mount a Seal Row Pad) for better chest flies that keep the tension exactly where it belongs: on your pecs.
With the new tightener knob and updated UMHW lining, the new 3" x 3" Shoulder Boulder fits securely on any 3" x 3" (75mm x 75mm) rack.
The 2.3" x 2.3" Shoulder Boulder is compatible with any 2.3" x 2.3" Cable Towers, All-in-One Trainers, or Power Racks with 2.3" x 2.3" (60mm x 60mm) uprights.
IMPORTANT: For user & equipment safety, ensure your rack or cable tower is bolted down or otherwise secured. Tighten the spin lock before each use. Locking on your weight plates with collars is highly recommended.
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- PSPeter S.Verified BuyerRated 5 out of 5 starsYesterdayBest Chest/ Shoulder attachment
The Bells of Steel chest and shoulder attachment is the best on the market! I love the easy to use and versatility it offers for any rack not just BoS. Add that extra ummpf to your workout without compromising space.
Bells of Steel USA9 minutes agoThanks a bunch for the stellar review, Peter! We're pumped to hear that the Shoulder Boulder/Chest Fly Attachment is a game-changer in your workouts. Easy to use and versatile? Just how we like it! Big thanks for the photo and video, too – they really bring your words to life!
Yours in strength,
The B.o.S. Crew. - AAlanVerified BuyerRated 3 out of 5 stars3 days agoDecent, poor quality control
Works as intended. Def has loose metal shavings in the arms which rattle when using. Irritating. Also the weight arms are misaligned, well the selector plate is. So the handles don’t start at the same angle. Irritating, if you have OCD. Does work fine for shoulders. Chest is meh.
Bells of Steel USA21 seconds agoHey Alan, thanks for sharing your experience and those snapshots. We’re sorry to hear about the loose metal shavings and misaligned selector plate! Please reach out to support@bellsofsteel.com if you would like to further discuss this issue. We appreciate you bringing this to our attention!
Yours in strength,
The B.o.S. Crew. - JBJustin B.Verified BuyerRated 5 out of 5 stars1 week agoDecent space saving attachment
Takes a bit of work to get everything adjusted properly and setup. Not as nice as a stand alone piece, but does the job. I find the workout is better if you hook to cable machine instead of using free weights. Free weights don’t keep muscles under tension for full range in my opinion .
Bells of Steel USA1 week agoThanks a ton for the detailed review and the stellar 5-star rating, Justin! We're pumped to hear that the Shoulder Boulder/Chest Fly Attachment is delivering as a solid space-saving solution for your setup. You're absolutely spot-on about the cable machine setup—that constant tension throughout the full range of motion really does make all the difference for maximizing those gains! Here's to efficient workouts and epic shoulder and chest development!
Yours in strength,
The B.o.S. Crew. - CWCory W.Verified BuyerRated 5 out of 5 stars2 weeks agoVery nice attachment! Blows up the shoulders!
Have really enjoyed this attachment! It works well for lateral raises, single arm front raises, rear delt raises as well as pec flys! Great addition to my home gym.
- TPTy P.Verified BuyerRated 4 out of 5 stars2 weeks agoBest in Class???
I’ve only had my Shoulder Boulder for a week at the time of this review, so I’m still dialing things in. As far as I know, this is the only unit in its class that can do a lying pec fly. The others I’ve seen only allow for standing pec flys, which don’t seem to offer the same stretch. I added roller pads to my Shoulder Boulder (see my video below), which allow more force to be generated in most movements. It’s not the same feel as lying pec fly or standing lateral raise machines, but for the money and footprint, it’s a value add for any home gym.
Bells of Steel USA1 week agoHey Ty! Thanks for taking the time to share your thoughts on the Shoulder Boulder/Chest Fly Attachment, and we're pumped to hear you're already dialing it in after just a week!
You're absolutely right about the lying pec fly capability — it's something we're pretty proud of since that stretch really does make a difference compared to standing-only options. Those roller pads you added sound like a brilliant modification to amp up the force generation, and we love seeing customers get creative with their setups!
We totally get that it's not going to feel identical to those big commercial machines, but we're thrilled you're finding it a solid value add for your home gym setup. That balance of functionality, footprint, and price point is exactly what we were aiming for.
Thanks for the honest feedback and for giving us 4 stars — we appreciate you!
Yours in strength,
The B.o.S. Crew
