Most of the folks tie their shoelaces with Square knots:



or with Granny knots:



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FEATURES:


  • NO-TIE LACING SYSTEM: Turn any pair of lace-up tennis shoes into slip-on sneakers. LOCK LACES are the original, PATENMade in the USA.
  • Style: Round Athletic Shoelaces (NOT VERY THICK) - Approximately 1/8" Wide.
  • 2 Pairs (4 Laces).
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  • Great Shoelaces for Sneakers, Boots, and Shoes.
  • The Best Way to Find the Length of Shoelace You Need: Remove the Current Shoelace From the Shoe, Measure it from Tip to Tip, This is the Length for the New Shoelace - Keeping in Mind to Add or Subtract to Your New Laces if Your Old Laces are too Long or too Short.



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FEATURES:


  • Nylon.
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  • Pair of shoelaces that are 3/16" Round and come in four different lengths. Perfect for adding some flair to your shoes. Great for all types of shoe.
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  • One Pair Per Order.
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To be continued...
OR some other less common forms of knots. These knots share a similar structure:

When you pull the “end side”, the lace slides and the loop shrinks, until the knot fails. These type of knots are easy to untie, therefore widely used as shoelace knots.

When you walk or run, your feet accelerate. So the end part and loop part feel inertia force. (Some math below...)

Suppose the acceleration of your foot is: aa, the length of the loop part is l1l1, the length of the end part is l2l2

The inertia force acting on the loop part is:

F1=2l1ρaF1=2l1ρa (2 is for two folds)

where ρρ is the linear density of the lace.

The inertia force acting on the end part is:

F2=l2ρaF2=l2ρa

Since the whole structure is equivalent to a movable pulley, the pulling force towards the loop is 1/2F11/2F1

So the total pulling force acting on the lace is |l1−l2|ρa|l1−l2|ρa
If the total pulling force is towards the end part (when l2>l1l2>l1), and the total force is larger than the friction, then the lace slides to untie the knot by itself. While when the total pulling force is towards the loop part and overwhelms the friction, the lace slides and the knot turn to a dead knot. In either way, some kind people on the street will mention that “you shoelace looses”

Therefore there are following suggestions to prevent the shoelace from loosing:

1, use a lighter shoelace. That is to reduce ρρ so as to reduce the inertia force.

2, make the loop part equal long as the end part. That is to reduce |l1−l2||l1−l2|, thus to reduce the total inertial pulling force.

3, use soft, flat laces instead of hard, cylindrical laces. Because the flat one has a larger contact surface in a knot to provide more friction.

4, Don’t use heavy aglets. Because that will increment the inertia force.