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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 sold more for publicity & 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 making shoes from scratch, from easily obtainable 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.

https://www.homedepot.com/p/ANVIL-1000-ft-White-Twisted-Nylon-Mason-s-Line-57478/300976861


#18 yellow nylon mason line for the heel strap.

https://www.homedepot.com/p/ANVIL-500-ft-Fluorescent-Yellow-Braided-Nylon-Mason-s-Line-57476/300960491?MERCH=REC-_-pipinstock-_-NA-_-300960491-_-N

The 2 colors of string are actually different materials which compromise durability for chafing.

E-6000 adhesive. 

Hot glue.

Cord fasteners with 8.25mm or bigger holes.

https://www.amazon.com/Haiker-Plastic-Toggle-Spring-Single/dp/B01JWJ911S

The toe strap uses a bundle of 8 x #18  white string, 19" long.  White is less durable but less abrasive.

The heel strap uses a bundle of 11 x #18 yellow string, 35" long. Yellow has proven more durable but more abrasive.

Strings are parallel rather than braided, which reduces chafing. 

Cord fasteners have to be ground out...

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  • Replacing toe plugs

    lion mclionhead06/06/2020 at 07:15 0 comments

    So with no need to commute, the lion kingdom washed its sandals after every run & the white toe plugs quickly became frayed.  It was time to replace them with yellow string, which despite being more abrasive, would hopefully not fray.

    Replacing the toe plug in permanently adhered soles was hard.  Your biggest allies in this part of the battle are the AMD knife, tweezers & blade screwdriver.

    To remove the frayed string, cut 1 side of the toe plug near the sole where it isn't frayed.  Wiggle the other side while pulling it & push the cut side with the knife.  The polypropylene protects the foam from pulling.

    Then push the new string in a hole, 1 loop at a time & under the polypropylene with the knife.  Use the tweezers to pull the loops out the other side.  Use the screwdriver to keep the polypropylene in place.  It's helpful to mark the position of the loops on the string. 

    This process passes 4 loops containing 8 strands of string.  Only 7 of the strands are used, since only 7 strands of yellow string fit in the unmodified farsteners for the old toe plug.  For the yellow string, the farsteners should be modified & 8 strands should be passed through, exactly like the white string.

    After trimming the string & CA gluing the ends, the sandals are ready.

  • Luna teardown & enhancements

    lion mclionhead05/11/2020 at 00:11 0 comments

    It was clear that the lacing was useless, so it was time to tear it apart.  The lion kingdom desperately wanted to stick with heal straps for such a heavy sole, while moving to string for the toe plug.

    This led to the strapworks gootube channel 

    https://www.youtube.com/user/Strapworks/videos

    There actually is a method to fastening straps.  Eventually ordered a pile of random fasteners from them instead of amazon.comAmazon.com tends to sell only large quantities of 1 type of fastener for a lot more money.  Sometimes the only plan is just to try out random ideas.

    2 weeks later, a bag of farsteners arrived.  

    The biothane was a waste, too stiff for any use besides maybe a strap on a vehicle.  It was all a casualty of not being able to see things in person.

    https://www.strapworks.com/Blue_Water_Tubular_Nylon_p/wsr-nyl-bwt-058.htm

    The best webbing has been 5/8" neon green tubular nylon.  The tracer marking may look ugly, but it's useful for measuring.  The prototypes began, heavily relying on hot snot for temporary bonds.


    The new toe plug was made from  9 19" long strands of #18 white masons line.  This was the maximum thickness which could go through the hole.  All the white string will be replaced by yellow mason line because it frays when it gets wet.

    Since past sandals had no indentation for the toe plug, lions had to make the toe plug loop around 2 holes.  The Lunas have an indentation for the toe plug, allowing a single length to be hot glued in.  This will be replaced by epoxy with some kind of mold release so it can be removed.

    Lions have black toes from wearing shoes.

    A simple cord fastener allowed the toe plug to loop around the side farstener.  There are a few other places to loop it.  The holy grail of sandals was achieved: independently adjustable toe plug, rear heal, & front heal  in a minimally abrasive system.

    The best design thus far achieved independently adjustable toe plugs & front ankle straps, no chafing from the plastic or the straps.  The key is to keep all the farsteners as close to the ankle as possible.

    https://www.strapworks.com/Plastic_Strap_Adjusters_p/psa.htm

    The ages old strap adjuster, 0.75" - 1", proved to be the best way to make an adjustable front ankle strap.  It could use some extra rounding of the edges to prevent chafing.  The rear ankle strap will eventually be a fixed length, as it was on the EVA sandals.  All suede was eventually replaced with nylon straps.

    The rubber soles eventually proved to be the  mane cause of blisters.  The traditional solution is a layer of suede on the rubber, but these are already super heavy soles.

  • Luna sandal details

    lion mclionhead05/09/2020 at 21:30 0 comments

    The lion kingdom bought the most expensive pair of sandals in lion history to aid its quest for the ultimate trail sandal.

    The heal bumper is some kind of neoprene sewed onto fake leather.

    The sole was the only differentiating factor lions could find between their $80 & $110 sandals.  It's much softer than Vibram's 1mm soling material but thicker.  The lace fasteners go below the sole, so they'll wear out.

    The sole contains Vibram rubber, probably a neoprene cushion, & a harder upper rubber.  Also note the plastic lace attachment is sewed together.

    The lace is a single nylon tube of some kind.  It doesn't use velcro but merely a fabric bungy cord of some kind to squeeze the end together.

    Fastener for toe plug & heal strap.  It adds friction to keep the 3 lace segments the same size.

    Heal to sole fastener.  Plastic to withstand the wear from being exposed under the sole, but sewed instead of glued or riveted.  It adds friction to keep the heel the same size.

    The toe plug has a fabric piece joining 2 nylon lace segments of different diameter.  The fabric piece is the scene of a lot of sharp edges.  The lion kingdom's 1st idea was to wrap it in scotch.

    It was a useful example of how to manage a flat lace.  Lions prefer separate laces for the toe plug & the heal.  No fasteners should be exposed under the sole, since no plastic is as durable as Vibram soling material.

    Obviously the soling material came from Italy & the plastic bits came from China, but there was a lot of sewing that could have been done in Seattle.

    3 miles in those ended badly.  The areas of the nylon lace system which were wrapped in bungy cords &  fabric attacked the lion paws.  The entire toe plug was a knife.  The plastic side fasteners rode up on the sides of the sole, creating a blister causing bowl.   At least the soles were effective at defeating rocks.  There won't be an easy off the shelf trail sandal.

    The nylon lace might be salvageable if it has a less abrasive covering on certain sections.  The side fasteners need to be replaced by suede or something soft.  It might involve sewing.  In the worst case, the entire lace system can be replaced by tried & true multi pass string.


    Rigid plastic fasteners which are fixed to the sole are how they prevent your paws from sliding around on hills.  Shoes trade stiffness for covering your paw in a larger area of fabric, so to get the same stability from a softer material would require turning the soles into shoes.  

  • 2 more pairs

    lion mclionhead05/03/2020 at 06:37 0 comments

    The mane addition with these sandals was extra bits of rubber in the highest wear areas.

    The lace ends were taped together into loops until they fully stretch.  Then, the laces may be cut again & hot glued or left as loops.

    The photo record says the last pairs were built in April & Aug 2019.  The April pair was only used once per week & went at least 400 miles.  The Aug pair was used 5 days per week & went a lot farther.  They finally got replaced, today.  The mane cause of death is the soles wearing down.  While the EVA quickly compresses into cardboard, the compression hasn't been the mane problem.  Alternating sandals for every run may undo some of the compression.

  • Cracked rubber

    lion mclionhead05/02/2020 at 23:04 0 comments

    The dream of improving the sandals continues to give way to the need to keep the current fleet alive as it wears out.

    It came to pass that a $40 sheet of soling material became cracked from being stored in a folded position. This sheet only yielded 2.5 pairs of intact sandals, but lions have realized soles can be created by gluing smaller pieces.

    In the last 2 months, a rise in the need to fabricate face masks from fabric caused a lot of men to start sewing.  

    This got the lion kingdom thinking more seriously about sewing straps instead of strings.

    Reviewing the Luna sandals offerings, their top line sandals are now $120 instead of $200.  That's cheaper than what lions paid for Hokas.  Their bottom of the line is $80 & sold through resellers.  They're all using a single toe plug instead of a toe strap.  The toe plug & heal all use nylon straps.  The nylon narrows down before inserting between the toes.  

    As it was when lions dropped $40 on a zeroshoes pair to get started, the trail sandal begins with dropping a certain amount on a Luna pair.

  • Trail dreams

    lion mclionhead09/21/2019 at 09:36 0 comments

    The current design has worked well on roads, as long as there are very few rocks.  It's pretty bad on trails.  Making minimal sandals bearable on trails has long been an impossible dream because they would have to be heavier & this would make the toe plugs more painful & cause more chafing from the string.

    As long as the weather wasn't humid & the strings weren't too tight, lions have gone 25 miles without any chafing from the latest toe plugs & strings, without any tape, but they do result in scabbing where the toe plug enters the foam.  A trail sandal needs to have straps instead of strings to distribute the increased weight & handle sideways forces.  The lion kingdom believes suede straps might do the job, but these require a quick fastener for straps instead of cords.  Velcro has proven very short lived in sweaty environments.

    https://www.amazon.com/10-Inch-Lever-Plastic-Buckles/dp/B00GS9L5U6/

    Levered buckles are intriguing but bulky.  It may be the good old fashioned 

    https://www.amazon.com/Plastic-Tension-Triglide-Backpack-Suitcase/dp/B07797M878/

    backpack tension lock is the best solution.  Unlike a backpack, they wouldn't require taking the sandals off  or odd contortions to adjust.



    For rock resistance, a combination of thicker soles & a hard inner plastic sheet might work.
    As much as stock materials have become unavailable anywhere outside China, there's still a place selling 4mm & 6mm vibram sheets to crazy guys who build shoes outside China.  

    https://www.leathercaresupply.com/collections/soling-sheets/products/vibram-7175-cherry-soling-sheet-shoe-boot-sole-repair-4mm-6mm-35-x-11-black?variant=49408936213


    The trick is adhering the inner plastic to the system.  The adhesive is permanent & thicker soles are expensive, so it would be a lot more expensive than designing the road sandals.  

    Digging up the 4mm soles from 1 year ago revived the memory of those early days.  Many months were spent building the early sandals.

    The polypropylene bonded slightly to foam but not at all to rubber. 

    1mm acrylic was cheap but immediately shattered when cut.  It would never do.

    The ideal plastic would be laminated in rubber like most modern gadgets.  That's done by having holes in the plastic for the rubber to pour into.

    Rather than find a material porous enough to adhere, the leading theory is having a foam layer, polypropylene, foam, & sole, with the sole adhered to foam as it is now.  The 2 foams would have to be held together with string separate from the straps going to the paw.  It may be a 6mm sole with no rock plate is good enough.



    The straps would have to be glued to the bottom foam, via the outside rather than via holes.  The trail sandal also needs a suede cover on top of the foam to increase grip when it's wet.  If everything is glued, it's real expensive to try again.  Perhaps, test articles can have string fasteners around the outside.

  • 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.  

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