What's the rule for strop rope strength?

I bought 3.97 cord with 50 lb (pound) weight load limit. Is that good rope for a strop? I weigh 150 lbs.

I use amsteel and its breaking point is 3200lbs.................aj

That would work unless you want to jump hooked in. Then something that will hold your weight ++ makes more sense ? Strop length is a personal thing. Leave it long enough that you can play with the larks head at one end until it feels the right length. You want to take the whole load on your spreader and have your arms at a comfortable length to do the steering. Usually a little over a foot. Start with almost 2 before making larks heads.

50 lb test will of course break. Go to a marine store and look for running line used for dingies (small sailboats). It is Spectra or Dyneema and is sheathed with braided material for wear protection. It will be 1000 lb test or more. Diameter is 1/4 or 5/16 inch- around there.

Or if you are not near water try a climbing shop.

Length will be 15 - 19 inches depending on body size and rig. Start long and re-tie the loop knot on one end shorter until you get it right (for you).

I get my strops from mountaineering or boat stores. I usually use 5-6mm climbing / boating rope that has a spectra core and dacron braided sheath as AC descriped above.

Length of the strop should never be longer than the length of your arm from shoulder to wrist, otherwise if you drop one handle, you won't be able to reach it to pull it back in.

Paracord works fine for me, idk what the breaking strength is but it holds me when I jump.