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Increasing speed & range of sandals

Hack sandals for running.

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Human shoes are an utter disaster for lions. After many Hokas & ASICs, the next step was sandals. They have since allowed personal record breaking speeds, but not as much distances.

Human shoes are an utter disaster for lions.  The single greatest idea for making human shoes fit lion paws came from 

http://fellrnr.com/wiki/Modified_Nike_Free

This is the only way we can run reasonable distances without blisters, pantar fasciitis, & black clawnails.  Over the years, as lion fitness improved, distances & speeds increased, & even this has run into limitations.  Barepaw running is unacceptable, because of the dog manure, human waste, & rocks.  Humans are nasty animals.

Another problem which has arisen is shoes are now being discontinued after only 1 production run.  Like books, programming languages & blockbuster movies, they're being positioned for only 1 use & thrown away.  Finding another shoe which works as well as last year's blockbuster can take years, if ever.  The only long term solution is something you can make from scratch, from historically available materials.

After extreme blistering in a 19 hour race, lions experimented with slow quarter miles in $8 Walmart sandals.  In the 19 hour race, shoes trapped sand & moisture from the beach track.  If they just had more ventilation, the problems might have been avoided. Sandals could actually hit decent speeds, with a bit more upswing.  It became clear the best chance lions have of reaching the next level is  modified sandals.  Sandals won't allow the maximum speeds, but they should allow the maximum distances.

Humans have since created

https://xeroshoes.com/
https://lunasandals.com/

extremely expensive versions of $8 Walmart sandals, with more straps.  $40 for the Xeroshoes Genesis would be reasonable if it wasn't for another problem.  The last pair of shoes wore down in only 3 months.  Most of a lion's life is spent running on inner foam rather than rubber.  

The Goog may actually embargo all but adsense paying commercial links, since it reveals no hacks.  Of course, lions don't sew & don't want to be like the male humans who do sew.

http://www.diyfootwear.com/huarache-sandals/

A nugget of info escaped the Alphabet corporation's embargo.

https://www.youtube.com/results?search_query=Huarache+Sandals

Sandals & how to tie them.  All these guys have pretty beat up feet & watching their videos conjure up foot odors.  Something is a bit off when it's only being done by men.  The dominant search result is https://www.youtube.com/channel/UCAq7JfGUobKA-pDDxVQ58Rw, but he's bald.  

1st lion run in sandals

Current bill of materials:

1mm Vibram soling sheet for the bottom, adhered with E6000 tacks:

https://www.amazon.com/Vibram-Tania-Protective-Sheet-Style/dp/B00I3LW9K2/

On top of the soles, a polypropylene sheet to reinforce string attachment points & defeat rocks.  Polypropylene squares if not worried about rocks.


For the top, 2x6mm white EVA layers tacked by E6000

https://www.amazon.com/Bulk-Buy-Darice-1199-20-10-Pack/dp/B0033M2FBY/

Leaning on a top layer of suede to improve traction in rain.

#18 white mason line for the toe strap....

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  • Death of cheap 2mm rubber

    lion mclionhead04/21/2019 at 17:47 0 comments

    It wore through a lot faster than the expensive Vibram.  The string did well, since these were only worn for 151 miles.

    Other changes would be reverting the length to the original Walmart  size, since the lacing was never accurate enough to precisely center the paw.  The string can't be trimmed until after some running.  Softer adhesive needs to be used to terminate the string.

    Finally had a sole fall completely off because of the hot glue becoming disengaged.  It could have been hot pavement.  The decision was made to use E6000 to adhere the soles from now on.

    The mane problem is E6000 reacts with rubber to cause it to warp.  The 1st attempt to deal with the problem was tacking the outside with hot glue after making a bead of E6000 on the inside.  This still didn't produce a durable seam & made it heavier. 

    A new Vibram sheet costing 25% more than the last one arrived.  Not sure if it was a tariff or Pandering Powell. 

     Getting the ideal seam requires a jig.  Cut up the last of the flip flops to press the seams together while not pressing the string.  It had been a long time since lions wore those flip flops for 13 miles & even longer since they were a radical design.  They lasted 50 miles if they were lucky.

    Glue pattern

    The plastic hardware was rounded to try to reduce the wear on the sole.

    Latest measurements of the plastic bits.  They have to be long & narrow to prevent the string from getting under.  

    Gravity was not enough to do the job & they still warped.  Wood clamps would be required.   Chinese are manufacturing magicians.

    Hot gluing over the CA glue areas ended the chafing from those parts.  The white string caused less chafing than the yellow string, but frayed more.

  • New pair

    lion mclionhead02/25/2019 at 17:34 0 comments

    The journey began with a template of a modified Walmart sandal with the holes punched.

    These can be arranged better, to allow more scrap foam to be reused.  You're out of luck if your paws are longer than 12".

    E6000 was applied.

    Soling was cut 1/8" bigger around the sides but not the length, to prevent sideways expansion of the foam from pressing the string directly on pavement.  The length of sole could be neglected.

    Then came the plastic bits for reinforcing the foam. The latest measurements for the plastic bits:

    https://hackaday.io/project/88623-increasing-speed-range-of-sandals/log/162191-death-of-cheap-2mm-rubber

    String was installed.  Sizing the rear string is hard.  For lions, the piece on the inside of the paw needs to be 5" & the piece on the outside of the paw needs to be 1".

    The rear string is pulled tight, with the relative lengths of the 2 sides kept at a 4" difference.

    Then the heel segment is pulled out to 1/2" beyond the back.


    The rear string is wrapped around itself 3 times.  The inner segment is now longer than the outer segment, allowing them to be fastened on the outside of the paw.

    Fasteners are installed.

    Rear laces fastened.

    Front laces are installed.  Important to keep the scotch tape as far from the toes as possible, so it's really a double pass for most of its length.



    https://www.amazon.com/SoleTech-Sole-Guard-Mini-Check-Rubber-Soling/dp/B00CCPYLWO

    After experiencing short lifetimes with 1mm soling material, a 2mm soling material was ordered.  Lions are grateful for the amount of soling material sold separately for the weird pasttime of making shoes. 

     The soles were placed directly over all the foam, laces, & plastic reinforcements, revealing a solid rubber underside. 


    Method of adhering the soles to the EVA:

    https://hackaday.io/project/88623-increasing-speed-range-of-sandals/log/162191-death-of-cheap-2mm-rubber

    Extra laces are trimmed.  CA glue is applied to the ends.
    The extra soling material was manely placed on the outside of the paw, where the string experiences the most wear.








  • New design

    lion mclionhead01/18/2019 at 07:27 0 comments

    A proper hole punch provided much more accurate holes than the drill.  The rear holes were 1/2" farther back than the Walmart template.

    Polypropylene squares for foam reinforcement returned.  Should definitely make the rear squares wider.  Considered using a single sheet of tough plastic over the entire sandal, to protect from rocks.  Such a variant is a must for trails.  Titanium would actually now be practical in place of all the plastic, if only lions had the money.  This would give the toughness of 4mm Vibram soles without the weight.  It's still hard to believe lions once ran on bare 4mm soles without any foam.

    The 2 layers of foam were tacked with E-6000.  1/16" string was painstakingly bundled for another attempt.

    Now the string would be completely above the soles instead of extending below the soles, hopefully providing enough protection for the 1/16" string.

    The soles were hot glue tacked to the foam, to allow the string to be replaced.

    The soles will need extra patches, when the most heavily worn areas are determined.

    After lacing, the laces were trimmed again.  Getting the right lengths of rear lace is still a bit of trickery.  Fortunately, a bit of effort can still shift the rear lace around without removing it.

  • 400 miles on 1mm soles

    lion mclionhead01/13/2019 at 08:07 0 comments

    400 miles since the introduction of 1mm rubber

    It manely wore in front.  The problem is the front has to be tacked to prevent it from flopping down.  When the material over the tacks wears through, it'll flop down.

    The protective flaps wore through.   Nothing to do but glue new flaps on top of the old ones.

    The string was indistinguishable from random fibers.  Blog posts since 8/26/18 show the string gradually fraying.  The frayed sections could now no longer be pulled through the holes.  The string was replaced on Aug 26, at least 700 miles ago.  It's amazing it was ever as pristine as it once was.  Not sure what causes the fraying or why it hasn't disintegrated.  

    With OSH closed, the smooth Lehigh 1/8" string is no longer sold locally.  

  • 24 miles in EVA sandals

    lion mclionhead12/26/2018 at 18:20 0 comments

    It was the fastest 24 miles a lion ever ran, manely because of the pawwear.  It was 2 days after a speed workout.  The toe plug tape wore through & a hot spot still developed on the toe. Need to double the tape.  Cushioning from 12mm of EVA was adequate.  Foot pain was about equal to the Hokas.  

    Got 2 blisters.  This was not from socks or a toe box but the toes rubbing against each other & the EVA.  There is going to be a lot of taping.

    The multiple plies of EVA definitely have to be tacked to each other & the sole to prevent them from sliding around.  Allowing the EVA to slide around causes it to tear.  

    Hot glue has been effective at tacking.

  • EVA lifespan

    lion mclionhead11/29/2018 at 05:27 0 comments

    100 miles seemed to be the limit of dual 6mm EVA sheets.  Only 1 sheet fully disintegrated.

    The compression after 100 miles was less than a flip flop.

    A way was revealed to swap the EVA without completely undoing the string.  Getting the lengths right continues to be a problem, since the lengths change as the foam compresses. Toe taping & careful placement of the cable farsteners has allowed the string to be tied at any tightness without chafing.  It might someday be practical to use knots.

    Definitely time to invest in a 1/4" hole punch.  The only ones big enough are the hammer & chisel type.  Drilling holes with the drill bit & exacto knife was terribly inaccurate, whether or not it weakened the material.

    With OSH joining the retail closures, the Lehigh NML48 string which was so easy on lion paws is a lot more expensive.  

  • 12mm EVA + 1mm Vibram

    lion mclionhead11/07/2018 at 23:45 0 comments

    After 28 miles, the 6mm EVA was crushed down to 2mm & the metatarsal started acting up again, so the decision was made to double up the EVA.

    A  small plate was sandwiched inside to aid the toe plug.

    Another flap was hot glued outside protect the toe plug.

    70 miles later, the metatarsal had no problems, the 12mm EVA was crushed, but it was still easier on the metatarsal than 6mm alone.  The mane problem was the EVA becoming very slippery when wet.  The 2 sheets also tended to slip on each other.

    The soles after 100 miles were on track to last maybe 500 miles.

  • EVA + Vibram

    lion mclionhead10/29/2018 at 17:30 0 comments

    $32 turned into a small sheet of rubber.  It definitely didn't look big enough to justify the price.

    https://www.amazon.com/Vibram-Tania-Protective-Sheet-Style/dp/B00I3LW9K2/

    https://www.amazon.com/Bulk-Buy-Foamies-10-Pack-1199-21/dp/B00KDMQB4Y

    To save money, work on electronics instead of clothing.  EVA foam &  rubber are what all running shoes are made of.  You too can buy the raw materials, just like China.  Vibram rubber is much harder than ordinary shoe rubber.  The choice of thickness was more due to weight than softness.

    The rubber had to be tack glued in places to keep from flopping around.  1mm was thin enough to use scraps to protect the string.

    8 miles revealed they were very good for road races.  They were lighter than flip flops.  The foam compressed like flip flops.  They were just as sensitive to rocks as flip flops, but less sensitive than bare rubber.  The most abundant foam is 6mm.  12mm might be serviceable on trails.  The 1mm Vibram  showed no wear.

    The foam is a brittle packing foam rather than the tough material a yoga mat is made of.  It's not as tough as the glossy 2mm foam sold locally.  The glossy 2mm might be a good liner for thicker soled sandals.

  • Back to sandals

    lion mclionhead10/25/2018 at 02:15 0 comments

    A month after going back to shoes, the swelling & pain manely disappeared.  Ran in sandals again & the swelling & pain returned.  It didn't return with the flip flops, only with the vibrams.  The metatarsal stress isn't from 300lbs of lion pressing down on it but from the whiplash as the toes follow behind the midpaw.  The whiplash is a much smaller force, but repeated thousands of times.  Might have to see a human doctor to finally heal the paw.  Being part human has these problems, despite being manely lion.

    Ideas emerged for using thinner vibram material, adding stock EVA foam on top, & ditching the suede.  Surprisingly, the existing lace holes have held stacked materials together nicely without any heavy adhesive.

  • Hoka vs home made

    lion mclionhead10/05/2018 at 02:13 0 comments

    Opening the toe boxes came a lot faster than it did back in the days of being used to wearing shoes.  The Hoka was truly awful, after 3 years of racing flats & sandals.  The severe hamstring pain, blisters, & plantar fascia pain returned.  It became obvious how they could cause all the tendinopathies of years past.    Cushioning converts force into heat.   The compression of the load bearing paw & expansion of the raised paw checks your paw strikes slightly higher than normal, exerting more stress on the hamstrings in their extended positions.   

    Metatarsal healing proceeded rapidly after converting to the Hokas.  Got back to 9 slow miles within a week, but swelling was persistent.  

    Then, got back to 18.6 slow miles.  The thick sole of a Hoka caught a curb & sent the lion down for the 1st time in 7 years. There was unbelievable hamstring pain from the Hokas & the historic initial plantar fascia pain which slowly faded away with use, but the feet didn't hurt as much as sandals.  Have come to recognize it as swelling in the upper hamstring tendons rather than glute pain, because the pain is magnified by sitting & eventually leads to pinching of the sciatic nerve.

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