It all comes together

As mentioned last time, I wanted to get all the outstanding brazing work completed before I went back to work in the new year. I'm now back at work but I'm pleased to say that I did manage to find half a day to go and hire the oxyacetylene and get the bits stuck together.

I'd accumulated quite a pile of bits ready for brazing and it was good to get them all attached to each other at last. There are 5 sub assemblies to be brazed:

The new bolts into the cantle plate.
The bolts into the spring carrier
The saddle post clamp
The lever pivot castings to the end of the fork legs.
The individual handlebars into the head and attaching the brake lever pivot.

I only made jigs for the handlebars and the lever pivots, the remaining assemblies being too simple to require holding, this proved to be a mistake as I'll explain later.

The handlebars and brake pivot are held in the correct locations with some very special frame building pins - old nails. unfortunately, I drilled the holes very slightly too large and the pins have a tiny amount of movement, this meant that the individual handlebars could move relative to each other and could end up not being aligned. I solved this by zip tying the bars to a thick sheet of MDF to maintain the alignment.

The lever pivot jig needed to be more complex and accurate, the pivots need to be concentric, parallel and correctly spaced relative to each other. They also need to be parallel to the main bearing housings. I recycled the old jig used to braze up the main bearings and with suitably machined spacers I was able to hold everything securely in the correct locations. I had to be careful brazing these castings as I had already had them nitrided and I didn't want to affect the hardness of the bearing surfaces. My idea was to use a large lump of steel as the spacer, this will double as a heat sink and hopefully prevent the inner races from getting too hot. I also tried a new brand of 45% silver solder this time, this has a lower melting point and should flash in quite quickly. I intended to go in quickly with a hot flame and spend as little time as possible heating the castings.

As always the first job is to thoroughly clean and degrease the surfaces to be brazed and then flux and assemble into the relevant jigs. The actual brazing went really well and the lever pivots are firmly attached and still hard after the heating. I've only cleaned up the handlebars and lever pivots so far, the saddle components have yet to be done.

For the first time I can now assemble all of the parts made to date. The sun gear still has a lot of material to be removed and the planet has nothing to attach to yet. The total weight at this point is 33lbs 14oz (~15.4kgs) which is on target as per an original.

It is great to have the basic bike together after all this time. As I mentioned before, I didn't use a jig to hold the saddle post mount and consequently it has come out at the wrong angle. It's only 5 degrees off but it will affect how and where the saddle sits and to my eye it just looks wrong, it not being parallel to the fork legs. You may remember that I wasn't completely happy with it when I machined it up. I'll make another one at some point.

Next week, I'll continue with the saddle.

In other news, we've had a little weather this week. It's been quite varied with snow on the Lindis Pass, very heavy rain on the West Coast that took away a few bridges, a tornado in Ashbuton and very hot Nor'West days like today. It's almost like we've had 4 seasons in one day or something. Hey, somebody should write a song about that.

Cantle Plate Cheating

For the first time on this project I have cheated, I have taken a short cut, I have not made something from scratch. I'm pretty certain that life will go on so I'm not going to loose any sleep over it. I could have made the cantle plate from scratch but as I had a suitable donor saddle handy, it seemed silly to be pedantic about it. Similarly I have found some springs that I can use for the saddle. The springs on this bike are much longer than usually found on Brooks saddles. I found them in a drawer in Scottish Dave's shed and he generously donated them to the cause.

The donor saddle is an old Brooks something or other and the spring mounting bolts are too wide at 4" centres, I need to modify the plate to chop out a section from the middle and rejoin it so that it still maintains the same radius, this requires a little thinking before getting the hacksaw out. This is in stark contrast to Mr. Middleton who is very fond of his welder. Mr. Middleton has been bragging that he has finished his bike before I have. Pffff.

First remove all the old paint and rust with a dunk in some acid.

Then make a little jig to hold the cantle plate while it is tweaked.

The drawing illustrates the section that needs to be removed 

and still maintain the correct radius and get the bolts at the correct centres.

The section duly removed.

Then mount on a suitable scrap piece of angle...

... and give it to the excellent young fellow Tweed Pete to weld up for me. 

The original rivet holes were too close after removing the section 

so I asked Pete to weld them closed at the same time.

Finally clean up top and bottom and drill the two new rivet holes.

I've also removed the old bolts as the threads were a bit cack and also a very odd size. I'll braze some replacement bolts in using my beloved 26 tpi cycle thread. In fact I'll try and get everything brazed up before I go back to work next week.


In other news, we have been away for Christmas, we went to Wanaka and spent a very happy week doing all the usual family holiday stuff. We took a couple of mountain bikes and explored the local tracks which were fabulous. I can highly recommend Deans Bank Track and the long loop along the north bank of the Clutha crossing at Luggate and coming back along the south bank. My mountain bike is almost an antique (naturally), it is a 1993 Cadex CFM2 and still going strong. It amuses me to ride 'gnarly trails' on a bike that I should have upgraded several decades ago. "You just rode that on that. Awesome dude"

And for the record, my lovely wife did buy me a Christmas present, she bought me a new T-shirt that I'm not allowed to wear in the shed. I bought her some earrings, thus maintaining marital harmony.

Saddle Mounts Part 2

Last shedweek I made the saddle mount, the near vertical post that clamps to the backbone. This shedweek, I've made the little doodad that clamps to it and carries the saddle springs. I'm not sure what the correct name is for this part but I'll call it the spring carrier for want of a better term. It's a lovely little thing, very pleasing to look at.

Spring Carrier Doodad.

Calculations on the original facile example and a few others I have handy showed me that I could machine the shape from a 1" bar.

The first step is to mill an identical flat on either side of the bar so that the final thickness is 0.75". This was the first proper use of my new milling machine, the finish is OK but not that great at present, I'll try a new belt to see if I can even out the finish. The finish is not important in this case since so much of it is going to be removed through subsequent operations.

The next step is to drill three holes in one of the flat faces, the two end holes are tapped at 1/4" cycle thread as a temporary means of mounting to a face plate, these end holes are where the springs will be mounted. The middle hole is used to centre the bar on the face plate.

Then bore the central hole to be a nice fit onto the saddle post.

Next machine the side on profile using a profile tool. This type of interrupted cut is very hard on tools, even using small feeds. The finish is unimportant since it will be hand filed later.

Next remount at 90 degrees using an old section of angle iron. Mark and bore the cross hole for the 3/8" bolt to clamp the carrier to the saddle post.

Then machine the profile of the side.

Flip around and machine the back of the carrier in the same way.

Finish with hand files and make the 2 bolts to hold the springs and the larger one to secure the carrier to the post.

In other news, I'm being tossed on the horns of a dilemma. In our house, we try hard not to go mad on Christmas presents. Sure, the kids get a little spoilt and they get things that I would have loved as a child but I'm talking about presents to each other, to my lovely wife. Officially we have a complete spousal gift moratorium. We both agree in advance not to be silly and to treat the festive season as a time to spend together as a family with the necessary reduction in shed based activities. Unfortunately, I happen to know for a fact that my lovely wife has bought me something this year. My daughter told me. What do I do? If I buy her something, I'll have let on that I know that she bought me something and if I don't buy her something I may as well go and live in the shed until next year. I can't win. I think the solution is to buy her a present and wrap it in a generic Christmas/birthday style wrapping paper, then hide it down the back of the sofa rather than under the tree. If I'm right and she has got me a present I can whip it out and still be in favour and if I'm wrong and she hasn't broken the gift embargo, then I can just keep it until her birthday in August. Sorted.

Whatever, happy Christmas to both of my readers.

Saddle Mount

I am a slacker. There, I've said it in public. I've had so little time in the last three weeks that progress has been slow. Also we've had a few weekends away and consequently my shedweeks have been minimalist to say the least. My focus at present is to get as many parts as possible ready for brazing. I don't own any oxy-acetylene equipment, I just hire it for half a day when I need it. This works out cheaper and safer. About a hundred years ago, I used to be a fire-fighter in the UK and I've seen a few cylinders go pop with fatal results. Acetylene is truly horrible stuff, totally safe when used correctly but lethal when abused. I get nervous just transporting it in my car. But I digress. To get value for money out of a half day hire, I like to get as much ready as possible before hand, hence the work on the saddle mount. In addition, once I've got the handlebars brazed on, I'll be wanting to make and fit the T grips. Before I can do that I need to be able to sit on the machine to position the grips at the best ergonomic angle for my wrists.

The original saddle mount.

As you already know, the backbone is elliptical which means that the seat mount clamp has to be elliptical to match the profile. It is easy to find a suitably sized round thing to use as a form when bending a round shape, elliptical things are not so common. I had a go at free bending a few samples but as I've previously noted, I'm not great at bending things and I wasn't happy with the results. The solution was to make a former so that I can repeat the bend as many times as I like. I have future projects that require elliptical backbones and I'm sure I'll be re using it.

Making the form tool.

First find some strip steel that is the correct gauge and then mill it to the correct width. I found a piece of an old galvanised dustbin that was almost the right size, I don't want the zinc plating but that's easy to resolve later on.

Place the strips into the form tool and using a series of suitable sized round things, squeeze the strip into shape.

The stages of bending the clamp to shape.

Next mark and drill the 5/16" holes for the bolts. Then mark and file the ends to shape. The bolts are 5/16" cycle thread with a slightly domed head, these will be brazed into the upper half of the clamp. Of course these need to be made from scratch, not being an off the shelf item. I used 10 mm coach bolts as the starting point, the dome being machined with my new ball turning attachment. For some reason, I forgot to take any photos of all of this so you'll just have to take my word for it.

At some point I removed the zinc galvanised finish by dunking in some acid for a few minutes. This is a violent reaction that gives off large amounts of hydrogen. I will not say if we collected the hydrogen for purposes of amusing children.

Zinc meets hydrochloric acid - violence + hydrogen.

The upright post that the saddle itself clamps to isn't vertical as you would ordinarily find on an ordinary Ordinary. Instead, it is inclined at the same angle as the front forks. You can see this on this woodcut from 1891, this is right at the end of production and the bike has more inclined forks than the earlier more upright examples.

Note that the saddle clamp is parallel with the front forks.

I've carefully measured the original I am copying and also measured directly from the assembled frame of my copy. The angle was the same in both cases which was pleasing. The saddle post has this angle milled onto one end to locate it at the correct angle on the clamp, to add extra support an additional piece is fitted around it, this piece has been filed to accurately fit onto the curved clamp at the correct angle. To hold this all in place a small bolt is screwed from underneath, the head will be filed off after it is all brazed up.

The saddle post has a flat milled on the front facing surface, I'll mill this after brazing. This is in contrast to the usual rear facing clamp found on most Brooks B70 saddles from the period.

Rear facing clamp, note the flat milled on the rear of the upright member.

Initially I thought that the clamp I measured was a 'Friday afternoon special' until I started looking at contemporary images and sure enough, the clamp is forward facing on the facile. It does makes sense when you think about it though, The geometry of the facile means that there is ample space to get in with a spanner, unlike a penny farthing, and it's out of the way when mounting the bike.

Front facing clamp, lots of room for a spanner.

I'm not completely happy with the clamp, but I'll braze it up and see how it performs when bolted onto the bike. If I need to, I'll simply make another one.

The clamp seems to be very flexible, I may need to use slightly thicker gauge strip.

In other news, I've been press ganged into being part of a works team for a mountain bike race next February. This means I have three months to get lean and fit. Over recent months I've been developing an excellent abdominal 'one pack'. Clearly things will have to change. We visited friends in Ash Vegas at the weekend and I rode the last 50 km from just the other side of Methven. The route is across the Canterbury plains and is slightly downhill all the way, I calculated the gradient at 0.6% which is nothing but boy does that 0.6% make a difference! Admittedly, I had a strong Nor'Wester blowing straight up my bottom bracket in the early part of the ride but this had died to nothing by the end. I've even ridden to work twice this week, once in 30 degrees Celsigrade no less. Last year I rode 15,000 km, this year will be much much less mainly due to injury, museum leave and badly inflamed wimp glands.

Handlebars - take 2

I have recently been introduced to an excellent young fellow known as Tweed Pete. Tweed Pete likes to tinker with old bicycles, indeed he is making one of these...

This is taken from Andrew Ritchie's Blog.

...and making a fine job of it too. 

This is his MkI, an improved MkII is already in the planning stages. 

In his own words, "old bicycles have bitten me pretty hard". Saying that Pete has a big shed would be a little like saying that Christchurch has had a few earthquakes. It is a most impressive shed, containing large amounts of spares parts and materials that will be useful for future projects. Or 'some old crap' as my lovely wife would call it. Like any normal man, I thoroughly enjoy poking around in other people's sheds. I'm trying hard to reduce my list of 'future projects' and I suspect that Pete is doing the same. He appears to be better at it than me as the last time I visited, he managed to get a couple of spare 1/4hp Crompton Parkinson electric motors in the boot of my car without too many complaints from me. I'll get my own back next time he comes round.

Tweed Pete recently put me onto a new source of chromoly tubing in NZ, the USP being that they sell the stuff by the foot, rather than only a complete 18' length. I found them easy to deal with and in just a few days I came home to a shiny length of plain gauge 0.75" x 0.049" chromoly tubing sitting on the doormat.

I've going to try a change of approach with making the handlebars. I have experimented and racked my brain (didn't take long) for a solution to my problem. Indeed, I've even had real engineers racking their brains to solve my problem. Engineer Dylan is another excellent young fellow that has contacts in the real engineering world. He has suggested that I get the tubing spun to produce the taper. Btw, it's worth watching that video, if only for the bloke's accent. Spinning is a bit like magic, I still don't understand it. I took my tubing to see a local spinner in his shed and he believes he will be able to do the job, The downside being that I will have to make a mandrel and I still have the problem of bending the finished tapered tubing. So before I go any further down that route I'm going to try something else.

Of the various original machines that I have seen or have seen photographs of, the handlebars fall into two distinct types, deep or shallow drop, with either pear or T grips. My dodgy back tends to prefer a more aggressive position on a bike so I'm going to be making my handlebars with a deep drop and T grips. The same as the Welsh and Austrian[1] bikes.

I've taken the plain tubing to a recommended tube bending company along with an accurate sketch of what I require.

The first attempt didn't go well as the chromoly didn't like the sharp bend.

We changed to a larger radius and all was well. 

It is interesting to note at this point what a high quality mandrel 

bend looks like like compared to a poor quality bend.

Actually that's a little unfair since to see a really bad bend you'd need to go and see Mr. Middleton.

Next I cut a sliver from the underside of the handlebar.

 I drew the shape on masking tape on a flat surface...

 ...and then transferred it to the tube.

Everybody should own a Dremel tool.

Cutting this sliver proved slightly tricky because I couldn't get in for the full length with the hacksaw. A Dremel with mini metal cutting discs made short work of this and I was able to get an accurate slice removed.

Next the gap was squished closed, this is a simplification since it is important that the round profile is maintained for the length of the taper. Simply squishing the gap would result in a sharp V at the joint, not satisfactory. Also the springy nature of the 4130 made this an interesting exercise.

Squished gap.

Then take the squished tubes into Christchurch to go and see Pete the welder again. Pete is one of the few people that I am confident outsourcing work to, I know from past experience that he understands my level of desired quality and he always delivers.

Welded gap.

I ran a little silver solder down inside the ends to disguise the inner seam of the weld, at the same time I normalised the weld zone since these will be repeatedly under stress cycles. Time will tell if they prove durable.

Finally dress off the welds and cut to length. 

Now we can see what the finished profile with a dry fit of all the parts so far. 

I can see a brazing day in my near future.

These handlebars have been something of an ordeal to make, probably the item that has caused me the most difficulty so far. Certainly they have proved very costly in terms of time and money, I am glad that they are done.


In other news, some weeks ago I read with great interest that the SOLO project has officially gone live. SOLO being "Search Oxford Libraries Online". And as everybody knows, The Bodleian is an Oxford library. I'll leave it as an academic exercise for the reader to find the appropriate link but suffice to say, there is now a wealth of down loadable material at your fingertips. For example, I have increased the number of Bicycles and Tricycles of the Year (Harry Hewitt Griffin) in my collection from 7 titles to 12 as a result. Happy hunting. Incidentally, last year I had a very rare opportunity to purchase an original pair of H H Griffins from 1883. They are both in excellent condition and in due course I will be duplicating them for general consumption. I had never previously seen the copies from 1883 before and I was tickled pink to find them. Coming soon to a blog near you...

[1] Thanks to Christian R. Conrad for correcting me. I erroneously assumed that it was in Germany. It isn't.  For some reason I am unable to respond to comments, I'll need to investigate this. But thanks, I do appreciate the information.

Mill Mantling

This week I have been more excited than a dog with diphallia. Allow me to explain.

Some time ago I was given a milling machine. Specifically a 1976 Mk1 Dore Westbury. The mill has only had one owner from new, that owner being a retired professional engineer who had built the mill from the basic kit of castings. And a fine job he had made of it too. I just needed to go and pick it up and bring it home.

Which is a problem if you happen to live in New Zealand and the mill is in England.

My father had been given a much larger Bridgeport and had no need of the smaller mill so asked if I wanted it. I enjoy a challenge (if you hadn't already noticed) and since I know the mill well and know it's history, it was worth pursuing. So during my recent museum leave I took time out to arrange the shipping. Now, getting a 76kg lump of iron around the planet is a non trivial task which is compounded by the strict MAF regulations here in NZ. I'm not complaining about those regulations by the way, I like NZ the way it is and support efforts to protect our biodiversity. The upshot is that I couldn't make a crate myself since all the timber has to be treated and stamped and certified and documented etc, etc, etc. It turns out that there are companies that specialise in moving lumps of metal about. I used Oakbridge because I happened to see an advert in one of the classic motorbike magazines that litter my parent's house. They were very easy to deal with and for a price, happy to take on the job. That price being somewhat less than an equivalent mill would cost here in NZ. I have seen several other Dore Westbury mills for sale here but they all seem to be either badly built (they were a kit, remember), badly abused or an interesting combination of both. None of these options appealed.

I took the mill apart, thoroughly cleaned it and arranged pick up of all the pieces. That was 3 1/2 months ago. Since then the mill has been on a long cruise and I've been wading through customs and MAF forms. Actually that's a lie since a local agent handled all that for me, I'm not good at paperwork you see.

Then on Saturday, this turned up.

Inside it was this. 

When my daughter saw the pile of bits, she asked if I was going to mantle it straight away. I liked that. It isn't one by the way, I looked it up

I just needed to paint the castings, Dad never got around to it

And put it back together. The quill is a little tight and I need to take it apart 

again to remedy this, I've probably got a little paint around the edge of the bore.

I only had the one piece left over at the end which was good. 

Dad, what is this bit?

I still have to bore a hole in the top of the workbench to allow the column to drop through. And to bolt the base down. And to route the switch cable properly.


In other news, I have been in touch with Norman, a fellow old bike enthusiast from England who has been following some of my ideas for making stuff. Norman has just started a new blog to document his own experiences and I urge you to go and have a look. In particular try and help him out with an identification for his latest project.

http://oldbikeshed.blogspot.co.uk/

As I have suspected for a long time, it turns out that fiddling with old bikes in sheds is rocket science. Well sort of.