Saturday, September 23, 2017

Tallbike seat stays etc.

Decided to preserve Healing seat stays because = simpler. First I took my Tarini frame and snipped off the seat stays and lengthened them to accommodate a 700c wheel, being too lazy to weld on cantilever bosses. The lengthening was easy, ugly and may need reinforcing if for no other reason than to pretend there isn't a stress concentration which there probably isn't because when you ram a tapered thickened seat stay backwards into another one and weld them together, there's an awful lot of thick and heavy steel sitting there.

Back to the original plan, and extending the bottom tube for the ostensible reason of creating a rear luggage rack. And preserving the faux seat tube for the front derailleur  mech. And snipping some seat stays off a few other bikes to see what would fit. Burning off the paint. Wire-brushing the ash. Pretending the ash molecules aren't pollutants and won't have any effect on the garden or on my unprotected lungs.

On to drilling 4mm holes for plug-welding, and since I can no longer get the machine onto the drill table, doing so by hand with the inevitable blood sacrifice.


Don't feel sorry for cut, feel sorry for stupid.

Since back-of-knuckle wounds aren't self-sealing, into the bathroom for plaster, knock mirror off shelf, into kitchen for dustpan-and-brush, mirror-shards wrapped and binned, plaster on, resume welding. As I say, don't feel sorry except for stupid.

Lots of shaping, lots of extra bits of tube, lots of weight. Did I really hope it was going to end up a lightweight? No, I didn't. And a bit more Googling reveals that one was right to be concerned about that elongated fork steerer tube. I found someone else who built one, and it cracked exactly where anticipated.

Gnarly seat stays to match gnarly chainstays


Methinks that parallelogram may need diagonalising.

My neighbour was impressed. Actually he was more impressed with Ron's bike which had luckily remained untouched, and since all it needed was air in the tyres I pumped them up and gave it to him, and he rode it down to the wharf this afternoon and came back puffed.

On to contemplate cabling, a job I hate. Couldn't get the cable to come from underneath the front mech cos there's that horizontal in the way. Why didn't I think of that before? Because I'm stupid, that's why. I needed a curly channel thingy to get the cable to curve round smoothly. Ideally this would have a 72mm diameter curve but one of those wasn't to hand, so I filed a groove in a snipping of Grotesquely Heavy Headtube from some other discarded bike.

Rubbish photo cos camera's gone All Funny. 

Sudden awareness that those seat stay cantilever stubs are too far apart. Squidging a Vee-brake at the top will impart more of a diagonal than a horizontal motion to the brake pads. Why didn't I think of that before? See above; stupid's why. They're four and a half inches apart. Need to be three.

Camera's still funny

Chopped a front fork in half to extract the cantilever stubs, and welded the entire fork section in place, using the altogether better idea of nipping the brake pads onto the rim while welding.

Must google Canon Powershot A430 and find out why it's misbehaving. The trouble when you inherit your electronick devices from your children

A bit ugly, but who'll be looking at this partic'lar bit of ugliness when there's so much more?

And on to making cable joiners. An intelligent person would simply go to the bike shop and buy tandem cables, but an intelligent person wouldn't be building this machine. Anyway buying stuff defeats the repurposing purpose. Besides, it's quicker to make a joiner than to cycle to the shop and home again, esp. if someone's thrown a bottle onto the bridge, which they have, and you have to go home and get a broom, which you do, because the Council won't come out for a month, which they won't.

Two bits of 1.6mm mild steel. Folds introduced with hammer and vice. 3mm screws 21mm apart.Gap at side 2mm to allow two 1mm gear cables to enter above one screw, cross the middle, and exit below other screw.

Tomorrow's task can be to weld cable stops on and get the back brake to work. And to fix the camera.


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Saturday, September 16, 2017

Tallbike frame

A hacksaw has revealed that the reason Healing bicycle frames weigh somewhat more than seven elephants is that they too were built with tubing of 1.6mm wall thickness. I was amazed. Makes for very easy welding, though. The downtube got its ends hacksawn and hammered to the approximate fit that is adequately hidden underneath Mig welds provided neither Mr. Knight nor Mr. English happen on them and make Adverse Welding Remarks.

Shaped

 Fitted

 Paralleled

Welded 

Then to rummaging about in the Bike Heap for scraps to turn into chainstays. Elderly BMX frame produced 7/8" chainstays ready-fixed to a strange 40mm tube, and slicing off most of the Ashtabula housing and a healthy bit of grindery persuaded this to fit the Healing BB shell. Some ancient MTB gave of its chainstays which terminated in squashed 7/8" tubing. Some other shards of unknown rear triangle, chopped off long ago and forgotten, slotted into these bits of 7/8". With a gap of 2.75" between them filled in (with bits lopped off the handlebar sacrificed to plug the fork steerer tube) to maintain the pretense that this was unbroken tubing, all was ready to weld.

Plug-welded through 4mm holes


Slightly gnarly welded chainstay

Then to contemplating how to align everything for attaching to the mainframe. Easiest is a jig but then you're left with a jig afterwards. So out with the bike stand (thanks, Matt) and a spirit level and a bit of manuka-wood propping up the back wheel until it's about in the right place and about in line and about vertical. Amazing how accurate this can be. Doesn't have to be manuka-wood though. Other timbers would have sufficed. Oak, ash or elm - even a stick of lacewood at a pin- oh shut up. Idiot.




Once welded, on with the faux seat-tube for the front derailleur mech. This tube's critical angle is gauged by holding up another rear triangle and tying a stick across the severed Healing seat stays and lots of filing and welding and whatnot. Do we keep the existing seat stays? Not sure at the moment. A straight line goes from rear axle to top headset and by happy chance clears the top of the derailleur mech tube, as determined by a stretched bit of inner tube rubber. That may do the trick with a bit of beefing up. It may prove too twisty, however. Four long undiagonalised tubes are scarcely a torsion box. - Shut up, computer.  undiagonalised is a word. - So for the moment we'll leave the Healing seat stays dangling there in the wind, ready to be used if needed.


Tomorrow I shall be forced to disturb the neighbourhood with a bit of antisocial Sunday morning angle grindering like as if I'm a bogan, and weld together some more bits of frame to make seat stays. Yes yes yes, I know it would be easier to use pristine tube but that would defeat the primary object. I'm not a Zenga brother. I'm trying to get rid of bits off-ov the Bike Heap. Repurposing, it's called.

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Monday, September 11, 2017

Tallbike

Ron has bought himself a new bike. Naturally he brought his old one round and parked it in my shed.



I'm told Healing bicycles were standard NZ issue in the 1970s. I already had three of them so I thought I'd make a tallbike. I got a scrap of paper and spent an idle half-hour sketching this.



No particularly good reason other than the fact that the idea exists.

Advantages:
1. Visible on the road, so drivers give more space when overtaking.
2. Penny farthing height (amusin') but, having a longer wheelbase, reduced danger of a header.
3. Uses up bits from the Bike Heap.
4. Any weight can be carried low and between the wheels.

Didn't want to go too high cos
a) difficulties of ascending and descending, & 
b) broken leg = not much fun.

I took a perfectly serviceable gentleman's mountain bicycle frame from a nail whacked in the shed wall and removed the 35mm top tube, it being the same diameter as a Healing steering tube. Popped it in the lathe steady and machined the end square to the bore.


Not for off-road use or stunting. Wouldn't want to over-stress that 18-gauge 2" steel downtube.

Chopped the downtube out of a Healing Tenspeed, cut the headtube in half, machined the lower half to fit inside the 35mm Tarini top tube and plug-welded it and then butt-welded it in place and tidied everything up with an angle-grinder. Dremeled the inside of the Healing half-headtube to fit a scrap of 18 gauge 32mm and plug-welded it in place.



Thought for a few minutes about which side a front Vee-brake cable  might like to lie before welding the Tarini top tube as an extension of the Healing headtube. Guessed there'd be a problem getting the top and bottom cups parallel, so I used a square to nip two blocks of aluminium onto a bit of box-section, and popped the extension between them before welding.



Only other major problem is extending the front fork steerer tube. The fork bearing cups are now twenty-three and a half inches apart. To extend the fork tube I need to weld a long 1" tube, and at its top, weld a piece of threaded fork tube onto which to screw the top bearing. The middle bit of this steerer tube is likely to bend when the front wheel hits a bump. A Huffy yielded a stiff piece of top tube: those old Huffys had 16 gauge frames in anticipation of being ridden by sturdy Americans. Another fork yielded a threaded end, and had the thinner 21mm ID which was sometimes used to ensure frustrating incompatibility between bicycle parts, but meant that this was of thicker gauge tubing. Machined all the ends square to the bore, natch. I found a steel handlebar from a  perfectly good gentleman's mountain bicycle, chopped bits off it, and machined them as inserts in the various bits of fork steerer tube.

Steerer tube bits cut and machined square to bore

Inserted and plug-welded through 4mm holes



Butt-welded together


Tidied up with angle-grinder. Fingers crossed that it's not so angle-ground as to be weakened.

It occurred to me that from the fork crown to the handlebar is three times as long as a normal tube, so when the front wheel hits a road bump, that tube running between the steering head bearings is 3x3x3 as likely to bend. Which is a lot. The ends of the frame head tube are of smaller ID than the middle of the tube, so I can't slip a bearing around the middle of the fork head tube. I consulted a design engineer on the other side of the world who builds these:




He promptly replied

Remember that if you have a fork tube 3 times the length, the force on the top bearing is 1/3 of the force on a short tube. I think you don't need to do anything. Easy to test anyway. Set up a tube or bar between supports at the proportional distances and apply a load to the end and measure the deflection. Move the end support to the other position, apply the same load and measure it again. I'd use the fork itself if I had it made, a heavy weight and a dial indicator, but you could use any material with the same cross section along its length to see what happens.


I think I'm going to see what happens.


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Tuesday, August 22, 2017

Clean and Green

New Zealand is. It often boasts about the fact, mostly on aeroplane videos, which also try to entice you to jump off that bridge at Hamner with only a rubber bungee to prevent liquification of all your insides and a more-or-less prompt but adrenaline-heightened death.

It's pretty well established that actually everyone hates cleanness and greenness, so most people try to alleviate the problem by throwing KFC and McDonald's wrappers out of their windows, and like the fact that you're never more than six connections from knowing the Queen, you're never more than six metres from a slime-infested beverage container in New Zealand. To be fair to them, KFC and McDonald's wrappers are largely paper these days, so if you can bear daily passing a Coca Cola cup on your ride, only the plastic top and the straw will lie there for ten thousand years. The paper will decay to something unpleasant in three months, and two years hence when the earwigs have finished with it you won't know it's there. Why d'you always find an earwig inside a paper cup at the roadside? Life is full of mysteries.

 Rubbish collected from the roadside

There are several paddocks I pass each day, and when I notice a cow in difficulties I drop in on Mr and Mrs Williams and they telephone the appropriate farmer and get him to attend to the calving. I know who the farmer is: he's a churchwarden up the valley. I even know his number - it's in the telephone book. It's just that I intend to be the last person alive without a mobile phone, and then people'll cheer me like they do Robert Marchand. But Mr and Mrs Williams like me dropping in: at least I think they do, because they always wave when I cycle past, and I think they like doing good deeds to their neighbouring members of the farming community.

Today was more-or-less the start of Springtime, and the roadside grass is still very short. Wherever the churchwarden has heaved a bale of hay over the fence for his cows, there are four snippings of baling twine, each two inches long, all of them a distracting blue, and all of them much more difficult to pick up later in the year when the grass has grown. It crossed my mind today that since the farmer is a churchwarden and probably dislikes roadside litter as much as I do, he'd probably appreciate it if I gathered all these unsightly blue snippings and dropped them in his letterbox. He could even tie them all together to make one long piece of baling twine, and auction it off for church funds. And he must find it really irritating that some horrid person is evidently following him round and, after marking the exact spot where there's a great armful of hay half on the road and lots more trampled in the paddock, throwing four short pieces of bright blue baling twine onto the public verge.


When you gather it all up there's more than you think, and it won't fit in one envelope

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Tuesday, July 11, 2017

Mid-winter

It is mid-winter. More-or-less. Many would disagree, depending on the hemisphere. Midwinter brings the Nelson Book Fair where the Lions Club - or it might be the Rotarians or the Freemasons - same diff. - charge you an exorbitant two dollars to wander about a freezing hall and examine millions of old books, and then charge you a far from exorbitant fifty dollars for a sackful of them.

This year I struck gold, viz., a List of Wedding Gifts at the marriage on 20th November 1947 of HRH The Princess Elizabeth and Lt Philip Mountbatten, which publication I have been looking for for, oh, approx. no years no months no weeks and no days whatever. But I bought it instantly. And better than gold, the previous owner had gone through it and diligently marked every person/persons who gave the royal couple a pair of nylon stockings. Mrs. L. R. Talbot started it off with two pairs of nylon stockings, followed by Mrs. H. Fielding who only gave them one pair. Miss Doris D. Crockett gave them a pair, Mr. Philip Ponder gave them two pairs, Miss Elizabeth Byerly two pairs, Mrs. Davis and Miss Sara Davis likewise, Mrs. Ella Wehage Pair (it doesn't specify the number), Mrs. H. Walters and Mrs. D Chamberlain two pairs, and Miss Elizabeth Cameron McCahill an extravagant six pairs.


Well, not all that diligently. He gave up by page 52, when with Mrs. T. J. Hume's stockings he'd reached a hundred, and that was only item 580. The book goes on to enumerate gifts all the way to 2,582 (Eight lengths of woven material, from the People of Blackburn), and since that was page 234 we can calculate that between them, they accumulated 450 pairs of nylon stockings.

Actually I rather feel this shows remarkable good sense. 1947 still saw rationing, and the more thoughtful of folk must've thought that Her Royal Highness was going to need quite a few stockings what with laddering, and they didn't want the future Queen appearing in careworn leg attire. I can imagine the Princess thinking "Yup, pop those in the suitcase when the Royal Train goes up to Edinburgh" whereas I can't imagine her getting so enthusiastic about A black basalt urn-shaped vase and cover on a pedestal bearing a medallion portrait of Louis XVI, carved with cupids in relief and mounted with ormolu with which they were encumbered by The Hon. Sir Jasper and Lady Ridley. Nor can I imagine Lt. Mountbatten settling down to an evening's reading of seven volumes of the Pocket Poets even if they were bound in morocco. I can rather imagine him looking at the donor's surname  and wondering if he could come up with an anagram (it was The Rev. Walter Fancutt).

Page 55 of 234pp

I, alas, cannot boast any nylon stockings, nor a Gold-mounted glass snuff-box with pheasant decoration on the mother-of-pearl lid (Viscount and Viscountess Portal of Hungerford) which must've got the royal couple pretty excited. I don't even have an Old lace handkerchief (Dear Mrs. Glass, the thank-you letter started). Not that nylon stockings or old lace handkerchiefs or a Paris porcelain Cabaret decorated with panels of figures in 18th century costume on turquoise blue ground overlaid with foliage in burnished gold (The Lady Duff) would keep me terribly warm in a New Zealand mid-winter.

All I can boast is my old sleeping bag and not-quite-matching Berghaus duvet coat, the latter a little frayed in places but, I'm proud to say, still keeping me as warm as when I was first given it.

Self-portrait in winter. Unf. I was the photographer (obv.) and therefore up a ladder, rather obviating the portrait bit.

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Sunday, April 30, 2017

Trailer reversing

I submit a list of all the people in my family who can reverse a car with a trailer behind it:



It is not, as perhaps you can see, a very long list. It occurs to me, as a result of an experience I just had which I shall not now discuss, that a particularly interesting motor sport would be this: to set up a row of cars each with a trailer attached, and have them race, in reverse gear, around a track. Curborough might be suitable. I would even come to watch.

In other and wholly unrelated matters, I have finally added a seat to the penny trike. Equipped with bits of wood to sit on, it proved popular among teenage visitors, but only one could ride it.


 Bits of wood as seat

 More bits of wood as seat

Sort of mobile park bench

It can now be ridden by one person, or by two side-by-side provided each co-operates using one pedal and one side of the handlebar, and it can accommodate two further passengers facing backwards provided they don't all mind their bums touching. It is not the fastest vehicle I have ever built, but it has occasioned some merriment from those using it.

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Monday, April 3, 2017

One year on

It is now zackly a year since I was cut for the stone, and since nobody who ever reads this blog registers the wit and vivacity of my literary references (see, there goes another one) I shall mention that the quote comes from Mr. Pepys and if you don't know what being cut for the stone means, here's (warning: pdf) a particularly graphic and horrifying account of it. Everyone thinks that Mr. Pepys was just the chap who wrote the Diary, but actually he was slightly importanter in the history of England than that - he was the chap who really founded the Civil Service. Which statement can rest unreferenced because either no-one cares or if they do care they're better informed than I am and likely to be disputatious.

I wasn't cut for the stone actually. I was cut for the nailing together of some of my trochanters. And the current posish is that apart from minor nagging aches, and the fact that I'm five minutes slower in the hour on a bicycle and not nearly as fast walking, I'm pretty well recovered, ta v.m. for asking.

However since we are not interested in my state of health, I shall now display a photograph of the foam chaincase which allows me to ride my delightfully slow two-speed bike through the rain without having to trouble myself about the chain going rusty.


And here is how I glued it together:


It just sits there, vaguely attached by the flimsy hole round the bike's frame, and being of light-weight, soft material, it makes no noise even if the chain or crank rubs on it.



One day I shall have to think about how to remove parts for maintenance, but I expect a sharp knife, followed by contact adhesive, will have to do the trick. For the moment, lubrication, if I can be bothered, can be by squidging the oilcan in somewhere. Being protected from road dust the chain can manage by being oiled though this I normally eschew, it being a very inferior form of lubrication compared to chain waxing. Which topick we need not go into since the unconverted will never believe it and the converted need no encouragement.

The highly observant, by which I mean Mr. Knight, will note that the rear wheel, formerly a four-cross, has been rebuilt as a three-cross owing to frequent pringling. The or'nery observant will note the common-or-garden pedals, and that's because I wear knackered old trainers when riding this bike cos it only ever gets used when it's raining. Which it happens to be today. Which is why this topick cross'd my mind.

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