Originally Posted by RJYU
Here's a good test to do. Pull tension on some sort of poly string at 28kg or so using the diabolo, and then after releasing tension, check the area that was in the grippers. Then do the same thing without using the diabolo. With many types of strings, you will see noticeably more "flattening" of the string when the diabolo is not used.
Here is a better test. The string in crushed by the gripper more if there is more tension on the string. Take a weight tie it to a string and measure the weight of the weight. Then wrap the string around a diablo and see if it weighs less.
Just in case you want a preview of what you are going to see I just did that. A 10 lb weight weighs 10.63 lbs hung from a string and when I wrap the string around my diablo it weighs 10.69 lbs. I think the reason for the 0.06 lb difference is the weight was free to swing when I did not use the diablo and when I did the string touched the the bar the crank slides on and that little bit of friction caused the difference.
You guys are too funny. Go on run you own test.