How to measure distance between Rings?

I work out usually in public gyms so everytime I do the rows in RC, I have to put them up and then take it down.  Is there any tips in making sure they're about 50 cm apart without bringing in a measuring tape?

Fingertip to elbow is 50 cm on my arm...

Ravn said:

Fingertip to elbow is 50 cm on my arm...

So there ya have it. Just bring Ravn's arm. Eazy Peazy.

I hang mine from the Smith machine where the smooth part meets the knurly part.  For an olympic bar, that comes out to 42cm according to this image:

Cut a piece of string to 50cm. Put it on your bag.

Just measure 50cm from fingertip to elbow along your arm and remember where that is. If it's slightly off it's really not that big of a deal.

Ravn said:

Fingertip to elbow is 50 cm on my arm...

Measured mine, shoulder to wrist is roughly 50 cm

alan tseng said:

Measured mine, shoulder to wrist is roughly 50 cm

Wow dude you have short ass arms!

my brother surfs and has about an easy 2in reach gain on me. he's 5yrs younger. I put mine at 19-ish inches too.