I started using gym rings when I had a short term membership to the YMCA and really like using them because it is a whole body weight workout that utilizes a lot of muscles for strength and stability. I'm not a fan of just lifting weights because I get bored easily and I just want enough strength and flexibility to do gymnastic routines and Parkour.
There are instructables on here that show you how to make your own rings using wood or pvc but I have a lot of bicycle parts and like to do things a little more cheaply and simply. The frame won't be explained here are it was just some scrap metal I threw together to make what I wanted.
Step 1: Materials
The rings are 12" (30 cm) wheels from a child's bike and they are very strong. You might be able to use larger wheels but I'm not sure if they'll bend or not. I took the axle and spoke out of the rims and put them in my junk box for future projects.
The blue thing is a pool noodle for cushioning around the rims
Also included in the material list is duct tape and 50' (15 metres) of rope, both from the dollar store.
Total cost of these rings is about $10.
Step 2: WrappingThe Rim
The pool noodle is slit on one side all the way down one side of it so that it can be opened up. Then it is cut in half so there are two equal length pieces. After that the foam is placed over the rim from the inside until it forms a circle. It is quite lucky that the foam was just long enough to wrap around the inside of the rim without any cutting. Then the foam is wrapped in duct tape.
The ring looks quite large but the foam compresses so you can get quite a good handhold. If it is too big for your use then you can always wrap it in foam tape, cloth, etc., instead.
Step 3: Just Testing the RIngs
I have some 3000 lb (1363 kg) tow straps that I used to test the rings before and after wrapping to see if they would bend or if the bare rims would hurt. The rims don't bend but they definitely need cushioning. The only problem with the tow straps is that they aren't as adjustable as I wanted so I figured out how to do it with rope.
Yes, I'm too cheap to go to the store and buy adjustable straps!
Step 4: Attaching Rope to the Rings
Attaching the rope to the rings and the frame I used various knots but you don't have to use the same ones I did. Just make sure they're strong and do what you want them too.
For attaching the rope the ring I used about 6' (1.8 metres) of rope folded back on itself so that it is about 3' (90cm) long with a loop at one end. The loose ends are tied to the rim with a buntline hitch because this knot won't come undone even with a lot of movement. Again, there may be better knots out there so use them if they're better.
Step 5: Attaching the Slider Rope to a Frame
The rope is folded in half so there is a loop on one end and the loop part is put over the frame and the the rest of the rope is inserted in the loop like a cow hitch but the rope isn't tightened.
This should work anywhere that there is a strong enough bar above your head. You don't need a specific frame to use this on.
Step 6: Attach Rings to Slider Rope
Take the rope on the rings and wrap it around the loop end of the slider rope in a cow hitch. You want the tail of the slider rope to be straight up and down as this is what your knots will slide up and down on. When you are attaching the rings you want to tighten the cow hitch as close to the slider loop as possible. This creates a very tight grip while still allowing the knot to slide up and down. The straight rope that is in my hand and pulling on is the straight part of the slider rope and has no knots in it.
Step 7: Locking the Knots
The knot that locks everything is a slip knot. You can see where the slide rope and ring rope are tight up against each other on the straight slide portion of the slider rope. Then once you have the rings adjusted to the height you want them take the straight slider rope and wrap it twice around the bottom of the ring rope just below the knot. Then bring the slider rope into the loop created where the slider loop and ring knot meet. Fold a portion of the straight slider rope back on itself and insert it into the wrap and tighten. Not sure if I explained this properly but hopefully the pictures will explain everything.
The reason this holds is that once the knot is done the slider rope is now a part of the knot and shouldn't move.
To readjust the ring height just undo the slip knot and slide the ring knot up and down the slider rope.
I tried using a Prusik Knot and a Klemheist Knot but they didn't hold like I wanted them too since they work better with two different sizes of rope. Plus I doubled up the rope for extra strength and that might also affect the holding of these two knots.
I weight 170 lbs (80 kg) and this holds me quite easily. Just make sure that you get a strong enough rope! The rope I bought from the dollar store is rated for 200 lbs (90 kg) so that's why I doubled it up and the knots reduce the working load by a bit. If it breaks I'll just buy stronger rope.
Hopefully you can understand this instructable and have fun!