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Adjustable TRX-style Suspension Work Out System - Less than $20

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I have been working out a fair amount in my garage but was having a hard time working out my back. I was inspired by this  instructable as well as the TRX website.  The TRX suspension system is very versatile and can be used for a wide range of exercises, but is really expensive. The other instructable is a great start, but I wanted something that would be a little more versatile. By making it adjustable, the handles can be used for a wide variety of workouts at varying difficulties. I often use them for rows (as pictured), pull ups, very difficult push-ups, and chest flys.
 
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Step 1: The Materials

The parts needed to make this are as follows:

2 - eye-bolts (I used 5/16" x 4")

2 - 1" x 6' locking tie-downs. I picked up these  ones at my local Harbor Freight for $7.99. They are plenty strong and have worked well.

2 - 5' lengths of nylon rope. I was surprised i needed this much for each handle, but it's a nice length. Make sure the cord or rope is rated to hold your weight. This can be purchased by the foot at home improvement stores or good outdoor stores. (REI, etc.)

2 - Handles. I sacrificed an old resistance band. PVC would probably work, but make sure the edges are rounded so they don't cut the cord.

Step 2: Assemble and Hang the straps

From here, it is pretty straight forward. Find a good anchor location. Make sure you sink the eye-bolts in to ceiling joists/studs. Drill pilot holes and then screw in the eye bolts.

Run the rope through the handles/pipe and tie a knot with a loop, trying to keep the same length for each handle.

Hook the straps on to the eye bolts. Keeping the latch at the top allows you to keep the excess tie-down out of the way.

Hang the handles on the other end and you're ready to go.
Looks good, but you really (I mean REALLY) should have those bolts secured into something more robust than just screwed into the wood. Through the wood and a BIG nut and washer would be better, proper load bearing beams and brackets would be better yet, remember you are putting a DYNAMIC load on those roof beams, which were only designed to take a STATIC load. As soon as a load starts MOVING the numbers start getting really big REALLY fast. Remember G-Forces MULTIPLY your mass and if you start making even a gentle swing you can easily double your body weight and more.

You MAY get away with it for a while, you may get away with it for several years, but it's not good engineering practice, and when it fails, that looks like concrete underneath you...
FryGuy2086 (author)  Dream Dragon3 years ago
That is indeed concrete beneath me! The thought has run through my mind, especially when I am facing the ground doing push ups. I thought about putting bolts through the beams as you described but was concerned that over time, the leverage created by the straps on a horizontal bolt might damage the 2x12. Any thoughts? The eye bolts are in there quit a ways and are holding fine, but I am definitely open to trying a new anchoring method that would be safer. Do you think a horizontal bolt through the beam is the way to go?
My gym hooks are placed in 2x4 and last a year now with no sign of failing , I wouldn't worry to hard about your system failing
No matter how securely the bolts are fastened, some matting on the concrete would probably be a good idea in case you slip and to reduce wear & tear on your feet from standing on concrete. The giant puzzle-piece type of matting sells for about $25/6 tiles (24 sqare feet).
FryGuy2086 (author)  CatTrampoline3 years ago
I think you are right. Currently, I just have a piece of carpet there, which isn't much padding. Everything against the wall in the pictures is sitting on the puzzle-piece mats like you're describing, but I will eventually upgrade it all to the mats. Thanks for the post!
It looks like a pretty nice set-up (I envy your clean garage!), but cringed at the thought of head or knee hitting that floor. Glad to hear you have a little padding anyway. Can't help it - I'm a mom & once broke my knee on concrete floor. I notice you have a nice big fan, too - a must-have in a work out room. Good luck in the contest!
Nice Job

If you were to drill a hole in the beam and then thread an machine eye screw with a nut you should be fine.

Cheers and may all your workouts be successful

The eye bolts you used to mount your suspension system are more than adequate to support your weight, and in fact, will handle much more weight and lateral motion than you'd probably ever hang from them. However, if the bolts you used have machine threads, you should replace them immediately with "lag bolt" style eye bolts of at least 3 inches in length. I've used lag style eye bolts to hang porch swings without any problems. My previous house had some that had been in frequent use for over 60 years without fail. I wouldn't worry about the open span of your floor joists succumbing to lateral forces too much, but if you're still concerned, you can nail some braces between them, just like you would do for an attic access.
I can't tell from the pictures if there is space above the beams, would you be able to fit a U-bolt over them? That way, you aren't modifying the material (by drilling or screwing) and detracting from the strength.
Those 2x12"s appear to be on 16" centers and while I can't see the span I think you'll find that many floors that people walk on, jump on, have cocktail parties on (live loads) are not built to that level of robustness. Modern code would give a similar member a maximum 18' span in a floor application with 40 psf live loading. My concern would be pull out of the threads in the wood, the beams themselves are not going anywhere. That said, I would not try this type of live loading on my garage with trusses built out of 2x4"s and with truss plates holding the joints together.

Even the pullout concern is probably overstated. For example, the GRK structural screws I typically use (http://www.grkfasteners.com/en/RSS_1_2_information.htm) have a pullout value of 1136 pounds per inch of thread engagement in wood with a 0.55 SG. Over time, the loads acting to rock the eyebolt back and forth could compress the wood and reduce the pullout strength but I say if ain't broke don't fix it.
Very true! You know your stuff ;)
Cool that you made your own set, but I'd suggest going all the way and using connected handles on one piece of rope. Balancing each side adds a lot to the workout.
FryGuy2086 (author)  fungus amungus3 years ago
I thought about doing this, and think it would definitely work better for some workouts. I chose to go with two separate handles because I didn't think I would be able to do pull ups, push ups, or chest flys as well if the handles were connected. I have never tried a real TRX system, and could be mistaken, but that was my thinking. Thanks for the input.
I LOVE doing push ups on the TRX! Makes it a lot more fun imo. Pull ups won't work because there's just one anchor point, but I'll have to try some chest flys next time.
bubbapebi3 years ago
The Wood Handbook from the US Forest Service is available for download free, either the whole volume at one go, or chapter by chapter.  You would be particularly interested in Chapter 5, which deals with the mechanical properties of wood, and Chapter 8, which describes fasteners of various kinds.

Here's the page:  http://www.fpl.fs.fed.us/products/publications/several_pubs.php?grouping_id=100&header_id=p

In another life I also used home-brew exercise machines.  If you don't work out with a spotter, it's best to take care.
Hewer3 years ago
I wonder if carefully measuring the straps and inking lines across the straps in say, 1 inch increments would help you adjust the strap lengths and keep them even. Maybe use 4-5 different ink colors in succession, so, if you move one buckle to a red line, you can quickly move the buckle on the other strap to it's red line, and you've got them at the same length. You'd use so many different colors so that matching colors are far enough apart that you won't mistake them and don't have to even count them to make sure you're on the right line.
FryGuy2086 (author)  Hewer3 years ago
Great suggestion! I'm going to give that a try. I think I will do one set of marks for the highest postion, and one for the lowest, as those don't need to change to vary the difficulty. In the middle, I'm going to put some color-coded lines, probably with 4-6 inch intervals. Thanks!
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