Long Wheelbase resumed

Okay, where'd we get to? Somewhere or other I got distracted. - Actually this isn't true - what really happens - always - is that I find the smallest, tiddliest job and spend weeks staring at it wondering if there's an easier way. There never is. I just have to Get On With It.

In this particular instance it was how to mount the seat. So I did. First I had to calculate (guess) where the chain run goes, and then dodge it with the seat support. That meant welding it on the back of the base, not beneath the base.

Note favourite welding clamps: inner-tube strip. Jigged with bits of wood screwed together to ensure parallel sides ten inches apart. Overall seat width = 12"

Next, something to stop the seat support flopping over sideways.

 Cut...

... precision cold-set  (okay, whacked with a hammer)...

 and welded to the frame.

About now it occurred to me that I might, just might, not get the angle of the seat exactly right at the first weld. Actually, not might at all. I never have; never will. Ten miles into the first ride I'll know it's wrong. Slightly wrong, but wrong. Twenty miles and my back will be killing me. Dead.

All of which I didn't want to think about but now had to. So another week of staring dumbly at it before it occurred to me that the 1 1/8" seat support is the right diameter to sit neatly inside a retired head tube, and those I have in abundance.

 Sacrificed Raleigh head tube, plus one of two U-bolts

 Notches filed to weld titchy tubes for the U-bolts...

 ...and U-bolt tubes welded...

...and the whole welded to the frame. Now the seat can tilt.

So the next bit of complete engineering paralysis - if I can dignify anything I ever do with the epithet engineering - concerned how to use the former seat stays of the mixte frame, as seat stays. - Gah? - so I'm repurposing a thing to be what it already is. God I'm stupid. - Anyway the complication was that the Frenchmen who make Peugeot frames use 13mm OD tube, which is 0.3mm bigger than the half-inch ID tube I had. But luckily Messrs Huffy turned out to be generous in their half-inch tube,

and the already chopped-up bike yielded two bits that would slide over the seat stays. By cunningly keeping the ends of the bridge between them (above) I had some sticky-outy-bits to file neatly to accept a couple more bits of tube -

- which made the welding altogether easier. And here they are, one of them already drilled and hacksawn ready for the clamping bolts -

Then all that was required - another week's dithering - was to figure out how to weld the back seat support...

and close the ends off...

and get it in the right place. Which I dismally failed to do. Because I'm useless. It was a quarter of an inch too high.

So I made the extra little bits to screw the slidy-clampy-bits* out of the Huffy dropouts and welded other clampy-on-y-bits to the slidy-clampy-bits in a sticky-outy-sort-of-way so they'd all fit. Approximately. There isn't a pivot at the bottom of the seat stays. Some bending must perforce take place, but it won't be much.

And I screwed them together with 5mm bolts which, I believe, conversation with my brother who actually is an engineer having suggested, have a shear strength of about a third of a ton**. Which I don't weigh.

And conversation with Matt*** at the bike shop yielded a 42mm back tyre, which I rather hope, may make up for No Suspension. - We shall see. -

Anyway, here it is, roughly ready to start turning into a bicycle.

From behind...

and from the side.

*slidy-on-y-bits and clampy-slidy-bits are Highly Technical Terms, strictly used by recumberent (sic.) builders. (Shut up, Mrs. Hague.)

**actually he said a 6mm bolt has a shear strength of half a ton. But six sixes are thirty-six, whereas five fives are twenty-five, and twenty-five over thirty-six is about a third of a ton.

***who rides up Marahau Hill in ten minutes. Hmmph.

Seat mounts

Mr. Knight thinks I have been a-slacking but it is not true at all. Well actually it is, but I'm not admitting to anything. For lo! I have finally Got On with It.

It is a fact that the fiddliest and most irritating parts to make are the small ones. Where'd we got to? Making the seat frame, that's where, and I think I mentioned that a frame needs to be twelve inches wide max, so that part of your bum sits on the frame and the whole of it doesn't become pinched by the sagging canvas of a wide frame, which (I have unilaterally diagnosed) causes what our American cousins so delicately call 'recumbent butt'. Actually I suspect part of their recumbent butts arises from too low a bottom bracket making them sit upright, putting weight on muscles which are working hard. Be that as it may, I have divined that narrow seat frames lead to Great and Unexpected Comfort and I sing their praises accordingly.



However, a seat frame does not of itself balance terribly well, so brackets must needs be made, and, given that seat frames are of 3/4 inch OD and perfectly good gentlemen's mountain bicycle handlebars are (sometimes) of 3/4 inch ID, it is the work of a moment to machine four washers to fit and four bits of five-sixteenths tube for bolts, and weld them all together, and then bisect the welded handlebar to make two seat brackets. - When I say the work of a moment I mean the work of about three hours. - It is the work of a moment when you have leant an incipient high racer against a small chair which has no support and you perceive is gently toppling over, to stick your hand out rapidly to grab it and inadvertently impale your left-hand little finger on a 3mm drill bit that you hadn't removed from a drill that you'd balanced on the chair, and then it's the work of a moment to rush inside squealing and get your wife to administer plasters. Amazing amounts of blood inside a left-hand little finger, believe me. - Well not afterwards of course - afterwards it's all spattered across the workshop floor.


Next it's the work of several hours to cut a bent crank - the alloy is lovely to machine so you never throw 'em away - into two lumps and to bore 7/8 inch holes in them for the top bits of the seat clamps, but it is the work of a moment to throw these across the workshop in a screaming hissy fit when you realise they should have had 3/4 inch holes instead.

So the next work of the moment will be to make fresh ones, and to weld some bits to the thingummies, so that they can be exhaust-clamped to the frame and John can balance on his seat frame. Which is all he'll be able to do if it rains as hard as it did yesterday when not a peep of sunshine was to be seen. And my god there was a fine view of the sun today, in front of which a small black dot was not moving. - I have just calculated that since the transit took c.6 hours and since the sun is c. the diameter of a dried pea at arm's length, we can daily work out where Venus will be. - It will rise approx 8 dried peas before sunrise tomorrow morning. Get your 90mm telescope on it and you will see a spectacular tiny moon-shape, Venus being an Inferior Planet. (Just reminding you of the astronomy that I know for a fact you've forgotten since you were 14 and last studied it.) And that reminds me of another Important Experiment which English readers are required to do: note whether the moon is a C or a D tonight, this being a remarkable proof of whether New Zealand really is upside down. It isn't. The Universe is actually the other way up. Australians are all the right way up, and Englishmen are all upside down, and absolutely none of them know it. Amazing, eh?

(It's a D tonight from here, a bit of a gibbous D, and since it's quarter to ten as I write this, a bit of a gibbous D lazily lying on its back.)