Bit like the man with the canoe ..........
Regards,
Kim Siddorn
The Pogo stick.
Sometimes when I went to the shed to get some wood for the stove, I'd notice the old red pogo stick lurking in the corner. I'd forgotten how much fun I'd had on it when I was about nine. Mind you, like a lot of fond memories from a childhood forty years ago, I probably only remembered the happy times when I fondly imagined myself bouncing down the road for hours without falling off or putting the end down a drain, setting all kinds of world records, and leaping Triumph Heralds in a single bound.
The reality was two or three lurching hops before falling forward, omitting to let go of the handle, and walloping my tender gusset as a result. I expect that I turned up wailing at the back kitchen door more than once with a quivering dewdrop on the end of my nose, holding my groin in one hand, and dragging the pogo stick with the other.
So I began to wonder whether it was possible to use a bit of the knowledge that I'd acquired since coming back to air rifles to try and improve it a bit. It was a very basic pogo stick. It didn't even have two handles at the top like deluxe pogo sticks of that vintage; it had one rubber thing like a bike handlebar grip. Actually, that's probably exactly what it was. It had two pedals - or footrests - with square rubber treads on each one, and a well-worn rubber tip positioned at the stick/road interface.
Once I'd got it out of the shed, at the second attempt - there was an enormous spider on the handle exactly where I grabbed it the first time, and I put it down again very quickly - a bit of rudimentary measuring using the trusty finger and thumb calliper suggested that this plan might well work.
The diameter of the lower leg of the stick was very close to that of the piston of one of my competition air rifles.Things were looking up. A couple of days later, I was opening a packet from Chambers, in which were a pair of piston bearings and a piston seal.
I set to. Several sheets of the Malvern Gazette were carefully spread out so that small parts like valve collets and small-end circlips could be set aside on clean newspaper in the precise order in which they were removed. The servicing manual, along with the routine maintenance schedule and exploded parts diagram for this particular model of pogo stick had been lost decades ago, and I didn't want to be dipping my hands triumphantly in the Swarfega only to spot an important component grinning at me from the bench.
All the cobwebs were cleaned off the stick. Over the next few hours, the rubber tip was eased off with the judicious application of a little penetrating oil, though it was found to have a small split which was almost certainly the result of a hefty Andy Robinson having attempted to clear his front hedge on it. Just to think that the last time that tip had come off was just over forty years ago, and that the little bit of gravel rattling round in the end had come from a road just outside our house in the outskirts of Leeds. Extraordinary. A bit of your own archaeology.
The footrest rubbers and the main grip were removed, and laid carefully on the paper on a rather poor photograph of the Mayor.
Standing bent over with the pedals behind my knees and the lower shaft disposed horizontally, I began to loosen the retaining ring, which held the two halves of the action together. With hindsight, I would have done well to remember the lesson that taking the FWB Sport apart had taught me regarding spring preload.
There was suddenly an almighty bang, and the lower shaft shot out of the main tube. It missed my nose by a fraction, whistled between the ears of the dog that was sitting on the floor disinterestedly chewing something unrecognisable, punched a neat hole in the back door and disappeared.
Some time later, having precisely calculated the trajectory by comparing where I was standing and the hole in the door, and thence the likely point of impact in the privet hedge outside, I still hadn't found either the shaft or the spring. The next day, with the benefit of daylight, I found them both by looking in a completely different place.
After some peering and poking around in the main cylinder of the pogo with an old cane from the garden, I recovered the piston, the spring guides, spacers, and the piston weight. The rather sorry-looking leather piston seal would have gone in the bin, but it fell out of the tube a second or so after the other parts, and the dog ran off under the stairs with it before I could stop him.
Using Hsing-ee's Guide to Tuning Old Springers from on here, I made a cup of tea, and had a biscuit. Armed with rags, molybdenum grease, polish, silicon oil, and a clean pair of underpants, I rubbed, greased, polished and siliconed, all the time enjoying the feel of crisp cotton underwear inside my overalls. The original spring was past its best, and after some complicated calculations and an immensely satisfying sit down in the smallest room, I decided that an Ox spring that was being used to hold the side gate closed would be an ideal replacement.
It took two of us three quarters an hour to get the spring back into the cylinder. Harry, our thirteen year-old, helped me as we grunted and heaved, using a length of two-by-four, a Workmate borrowed from John, and a pair of imitation Mole Grips that were actually made in Spain, and had 'Gorilla Grips' stamped on the side in Spanish.
We had to stop twice in two minutes when, as a result of straining a little too much, Harry let out two extremely amusing and very squeaky little farts, and we both fell about laughing. We stopped for a further five minutes shortly after this, while he went and had the poo that had had an aroma of inevitability about it...
With all parts judiciously greased and lubricated, new bearings and seals installed, and a fresh rubber tip from a walking stick that I found under rather mysterious circumstances in the hall cupboard, it was time to try it out.
Harry went from being smell-maker to enjoying a brief spell as assistant mechanic before a rapid promotion to test-pilot in the space of a few short minutes.The newly refitted pogo stick, with its paint sparkling in the sunshine was propped the wall outside, and I helped him climb aboard. I couldn't help but think of John Glenn, Gus Grissom and the other daredevils who took their lives in their hands as the laid the foundations for man's race to the stars. The theme tune for The Right Stuff came into my head as I aimed both my intrepid son and the pogo stick at the azure blue above, gave him an encouraging wink and a firm, fatherly handshake, and stood back.
The first bounce was remarkable for several things.
Firstly, it was clear that as a result of fitting the Ox spring, the pogo stick was now running decidedly hot, as my son described a neat parabola at an altitude of about seven feet, before coming to rest in an ungainly heap by the old wheelbarrow. Secondly, the twang was unbelievable. Zebedee would have been proud. Last and by no means least, the muffled explosion and large cloud of smoke that accompanied that first bounce suggested that something wasn't quite right. The internal detonation had also blown off the rubber handgrip, and the last we saw of it was a small black sausage-shaped missile hurtling into the sky in the general direction of Worcester. It was clear that I had been too liberal with the oil, and that there had been a certain amount of seepage into the transfer port. Notwithstanding the rather pleasant smell of burning oil that goes with dieseling, I should be grateful that the handgrip wasn't fired straight up Harry's nose.
So we had it apart again, ground half a coil off the spring, and took out all the preload washers. The problem now is that no matter how much you jump up and down on the footrests, the rubber tip is a good inch off the ground.