So the last few days I’ve been thinking of trailer redesigns.
I’m used to running very ultra light in kit choices – for instance in the run across the
UK I ran my whole sleeping system weighted in at 700g – that’s for tarp, bag, bag liner and
sleeping mat – all cut down to give barely enough protection where needed – so my whole
‘camp’ weighed in at 1/3 of the water I was carrying at any one time.
I won’t be going ultra light in this event as the kit needs to be slightly more durable,
and in some countries at certain times of year I’ll need heavier duty sleeping bags etc.
The main reason for the trailer is to allow me to carry large amounts of water/food when crossing Australia, and rural Russia – where in some parts I may go hundreds of miles between towns/fresh water.
Rationing water (i.e. if very hot sleeping under shade in during day and running through the cold of night) I can get by on 4litres a day – covering 30 miles, I’m sure I can run with 30kg/litres of water (which will become 4kg lighter each day) and this will give me a range of 7days/230+miles in between water stations/refills.
with kit/food/water/trailer weight the heaviest I hope the trailer will ever get is
first aid 1kg
= 60kg = 150lb’s
but this is only when know I have to run a huge distance to refuel water/food –
200+miles, if towns were only 100 miles apart, I can half the water/food weight saving
and in areas where only need food for one day then weight will be around
kit 10 kg
first aid+electrics 2.5kg
= 24.5kg / 60lb’s
The design keeps changing in my mind at the moment I’m looking at developing a two wheel
version like a traditional rickschaw – but with the weight offset to the rear of the axle
behind me – this would mean that the handles, either held in my hands and/or attached to a
harness – actually lift me up slightly rather than weigh me down – obviously the energy
needed to run will still be greatly increased as towing the extra 60-150lb’s but the
balance of the rickshaw can be adjusted so that my body has say 20lb’s of upward force
acting upon it.
20 lb’s sounds like nothing right? Wrong!
For a start if you’re used to running with a backpack you’ll know that even 10lb’s is a heavy load for more than an hour and very quickly fatigues your legs, having negative 20lb’s would be amazing.
The main reason I’m heading in this direction is minimising pressure/risk of stress fractures on bones.
Considering that foot strike is accelerated by gravity at about 1.5 magnitude of weight at a moderate pace then I estimate I can save 30lb’s of pressure/shockwaves shooting through my feet/legs/body on each and every foot fall (reducing bodyweight by 20lbs will reduce shockwave pressure by 30lbs – as gravity won’t act on this load).
50km a day = 60,000 steps
60,000 x 30lbs = 540,000 lb’s less stress on my metatarsals each day = over a month that
30 days x 5400000 = 162,000,000
162million lbs less stress per month on each foot!
Just by shifting the weight in the rickshaw to the rear of the axle – so that instead of
weighing me down or being neutral – I have to lean on it/use a harness to bring it down
thereby de-weighting my legs by 20lbs.
The design is going to be key – but in the example I described above the muscles will be working harder – i.e. carrying 40-80% of bodyweight along on top of normal
weight but the risk of bones/stress fractures should actually be reduced quite
considerably – this wouldn’t be the case with a 3 wheeled design – where there is the stress of extra load to tow and slight downward force applied through harness-into the lower legs, which greatly magnifies the risk of stress fractures.
Stress fractures/lower leg muscle tears/strains are my biggest concern during this run –and so the design has to be right. Plus by removing the front wheel I reduce much of the trailer weight/size and also remove the risk of people claiming I could have cheated on completion of the run – a 3 wheel design would be easy to sit in/on and roll down all downhill’s if no one was around – this could be quite tempting, a two wheel rickshaw/trailer can’t do this!
I’ll post up the pictures of mark 3 trailer when it’s built and perhaps a video demonstrating the difference in running style that moving the counterpoint of the balance of weight on the trailer makes – should be interesting (well if you like running crazy amounts!).