Because of simplicity. I am now thinking if a L shaped bit of metal that is stackable. Five in a packet.

The L shape is wedged (maybe hammered in) between the ground and the wheel so the wheel will roll over the tack. The side against the wheel is similar to a cheese grater and supplies the bite grip to wheel. As the wheel climbs the L shape the weight forces the tack into the ground giving a flat grippy escape.

No laughing kids involved, just lessons in friction and weight.
-- wjt, Aug 16 2014

Sadly, only four in a packet. http://i.ebayimg.co...5)jJbDrw~~48_35.JPG
[2 fries shy of a happy meal, Aug 16 2014]

Maybe the units could have fittings that allow them to be linked together ?

It might even be possible, given enough units, to form them into a continuous loop passing round both front and rear wheels … just a thought.
-- 8th of 7, Aug 16 2014


This is sort of baked by a product I carry around in winter called Tow Truck In A Box. [link]

Works well in snow... not as well in mud.
-- 2 fries shy of a happy meal, Aug 16 2014


A simple (rarely but possible) hinge mechanism may allow use for both mud or snow and would make the tack non disposable.
-- wjt, Aug 16 2014


// Have you ever tried a line of Tow Truck in a Box where the 2nd and 4th are upside down? this might give better mud traction. What surface is on the back? //

Both sides are identical other than how they interlock but there is a very prominent [this side up] marking to keep your tires from wrecking the coupling.
When it comes to mud they come flying out from under the tires with quite a bit of speed the first time you try them.
-- 2 fries shy of a happy meal, Aug 16 2014



random, halfbakery