DIY InStep Tear Repair Extraordinaire

With the increasing scarcity of footbag shoes (Lavers, Quantums, Gunits, ect) it is becoming ever more important to extend the life of your shoes as long as possible. One common problem that causes an otherwise decent pair of shoes to be retired is the dreaded instep tear. The instep tear starts and spreads from the clipper sweet spot where the instep fabric meets the sole and eventually becomes large enough to swallow the bag and make it difficult to perform sets from the inside surface. The underlying cause of the tear is an increased amount of stress in this area which is exacerbated by the following factors:

  1. When you crank your ankle into a “fist” for a clipper or inside stall the fabric is stretched very tightly in this area
  2. The bag hits this area most often and causes more cyclic stretching
  3. Whenever you have an interface between a hard rigid material (shoe sole) and a soft flexible material (instep fabric) there will be a stress concentration in the flexible material nearest to the interface. The larger the difference between rigidity the greater the stress concentration. Most footbag shoes glue the instep fabric directly to the sole causing a huge stress concentration in the fabric closest to the sole.

instep_holes01_stress

I had previously repaired the Quantum 2 shoes above following a tutorial posted by Anssi where I directly re-stitched the instep fabric back to the sole. The repair extended the life of the shoes another 6 months or so, but then tears and holes started forming again. In order to improve how long the repair keeps the shoes playable and decrease the difficulty of performing the repairs I made the following improvements:

  1. Pre-drill holes in the soles of the shoes with a power drill to make it easier to get the needle in and out rather than trying to use the needle to make the holes.
  2. Add a material with an intermediate tensile strength between the rigid sole and fragile instep fabric to decrease the stress concentration on the instep fabric. This improvement also increases the length of the instep fabric allowing it to be sewn to its original tension instead of being pulled even tauter if you re-stitch directly.

I have performed this improved repair on two pairs of Quantum 3 shoes with great success extending the life of each pair by more than a year. The required equipment and supplies and detailed procedure for performing the repair can be found below:

Equipment & Supplies:

Procedure:

1. Mark dots with a pen where you will drill holes along the length of the sole spaced about 5 mm apart along the length of the tear. I tend to make the hole spacing a little tighter near the clipper stall area in order to provide more support for the fabric.

instep_03

2. Secure the shoe in a vise with the instep facing upwards. I usually put some shop towel or foam (not shown in picture) between the shoe and the vise to help prevent gripping damage.

3. Put on safety glasses and use a power drill with 1/16” drill bit to predrill the holes along the uppermost part of the sole. I do not recommend putting your hand into the shoe while drilling as there is a danger that you may drill a finger. If you feel like you need additional support to prevent the sole from flexing while drilling, handi-clamps supporting the sole on each side of the hole are a good solution.

instep_clamp

4. Gently cut the instep fabric along the length of the tear with a utility knife to give a clean and straight edge that can be sewn to.

instep_exacto_arrow

5. Unlace the shoes to make it easier to get your hands into the shoe for sewing.

6. Find a piece of synthetic bias tape that is stronger and more durable than the instep fabric and cut it to the length of the tear. I didn’t have any bias tape, so I used some trim from an old pair of basketball shorts

bias_tape_dim

7. Fold the bias tape around the edge of the instep fabric and pin in place with bobby pins or sewing pins

bias_tape02

8. Sew the bias tape to the instep fabric using the denim thread and a needle. Use diagonal stitches going from the direction of the heel to the toe

bias_tape03

Then come back again from toe to the heel with diagonal stitches orientated such that you end up with little crosses or x’s along the length of the bias tape.

bias_tape04

Make sure to smooth out the bias tape as you go to prevent material bunching. Also make sure the instep fabric is pushed in far enough to the bias tape to catch both the upper and lower stitches. I have included an additional image from the inside of the shoe for your reference:

bias_tape05

9. Tie knots with the thread on each end of the bias tape and add a dab of super glue to prevent it from unravelling.

10. Sew the bias tape to the sole of the shoe using the denim thread and the predrilled holes. Use straight stitches going from the direction of the heel to the toe.

sewing01

Then come back again from toe to heel such that you end up with a continuous line of stitches along the sole.

sewing02

It is relatively easy to push the needle through the holes from the outside to the inside of the shoe, but it can be difficult to find the holes going from the inside to the outside. To overcome this I pushed a sewing pin through the hole I was trying to go through and then used that to line up the needle on the inside.

sewing03

Don’t worry if you sometimes miss the holes that you predrilled and end up forming new ones. If you have weak hands like me and it is still difficult to push the needle through even with the predrilled holes then hold the needle with linesmen pliers instead of your fingers as you push through.

11. Tie knots with the thread and add a dab of super glue to prevent them from unravelling.

12. Carefully spread a little bit of shoe goo along the length of the stitches on the sole to help prevent them from breaking. Be careful not to get any shoe goo on the fabric or bias tape or it will cause it to stiffen. I recommend wearing nitrile gloves for this step, so that your fingers don’t get all sticky.

13. Go have fun and play footbag in your freshly repaired shoes!

sewing04_smiley

Written by Rory Dawson

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