A Riveting Post

The promising start to the saddle making last week didn't end well. I got the saddle top cut out, creased the edge, cut out the vent and then screwed up the rivet holes. I tried to punch them through from below after marking the positions. The punch tended to wander a little going through the thickness of the leather. The result is that whilst the holes are lined up correctly with those in the cantle plate and the nose piece, the upper sides of the rivets do not line up perfectly on the top side of the saddle. Since I have plenty of leather, I chalked it up to experience and made another. Tim has told me how he makes his holes so this time should be better. Also the second time around I made a few changes to how I stretched the leather top over the block to make the process slightly easier and quicker. I didn't work, it took me longer. For some reason the second top is softer than the first one, this one marks very easily whereas the first one was quite hard, I'll carry on though and see how it works out.

Right where did we get to?

First thing is to cut the leather off the block and make it the right shape.

I asked Tim about how to get both sides the same and unfortunately there is no easy way. Fortunately the facile I am copying still had the original saddle leather so I was able to accurately copy the shape and dimensions.

Next run an edge beveller around the inner edge to produce a smooth chamfer.

Then dampen the leather slightly and run an edge creaser around the outer edge to

 produce a line. This requires care, particularly around the tight bend on the nose.

Then bevel the outer edge.

Then cut out the vent from the top of the saddle. 

I took measurements, photos and a rubbing from the original since I felt this was important to get the dimensions correct. Tim advised that I get a clickers knife to cut the vent. I failed to find one anywhere but I discovered that there is an easily available Stanley knife blade (5192) that is very similarly shaped. The blade is reasonably easy to control and well suited to this job. As an aside, Mr Middleton recently introduced me to diamond files. They come in at least three grades, the finest being of most use to me. I've been using mine to touch up high speed steel cutting tools in the lathe. I recently spotted a curved one and bought it with a view to honing these hooked Stanley knife blades. It turns out that I can get the Stanley blades sharper than new with it, scalpel sharp in fact, I'm most impressed and if you don't already own one, go and get one immediately if not sooner.

Next make the rivet holes. 

This time I took Tim's advice about the rivet holes and managed to get them in the right place. The upper sides need to be countersunk to allow the rivets to lie flush with the surface so that clothing doesn't catch on them.

Dye all the cut edges and when dry burnish to a gloss finish, 

I cheated and used my polished mop to do this. 

Lightly toasted leather doesn't half smell bad you know.

Then comes the bit that I was nervous about, the two creases along the sides of the saddle top. These two lines have to be the same and are done freehand with no guides. I marked the positions lightly with pencil to make sure they were symmetrical and then just went for it. I don't have the correct creasing tool for this so I smoothed the edge of an old fashioned steel tyre lever and used that.

The leather has to dampened again before creasing the line.

Then rivet the top on using copper rivets. I had just enough genuine 1/2" Brooks rivets left over from a previous job. Tim advised that these rivets are too large to be historically correct so I turned them down in the lathe until the heads were 3/8" as per the originals. I hate turning copper, it's so soft that it's hard, a little like sweeping water into a pile. Or herding cats. Or something.

The five holes that I had drilled, the three in the nose piece and the two new holes in the cantle plate were easy to rivet since I had sized them to the rivets. The four original, outermost holes in the cantle plate were larger and I couldn't get the rivets to hold properly and consequently had to remove them and have a little think. Of course I had no rivets left so I had to make some more from some much larger copper rivets used to hold truck brake shoes on. My Father has a large pot full and I stole some many years ago. This time I made some little copper washers and used them as roves to hold the tension on the rivet whilst I headed it, this worked out well. I'm not completely happy with the leather top, I think I could do better but I'll ride it and see how it works out in use.

The saddle is still not yet complete, I'm having a makers stamp made but it hasn't arrived yet. I'll post a photo when I get it.

I can now sit on the bike, and very comfortable it is to, which means that I can now make the handle T grips and get them at the right ergonomic angle. More later.


In other news, this week we've had a bad dose of redundancy going around at work. It's interesting that when the list of redundancies is announced all those on the list become work place pariahs. The fortunate few remaining in employment no longer make eye contact or want to linger and chat. They may catch redundancy you see. For those readers familiar with the traditions of English pantomimes.

"Where's my career"?

All together now children, "It's behind you".

 To my surprise, I am one of the lucky few to be kept on. I've had a lot of time off this year to look after my children and I didn't expect to survive the cut.

I explained what redundancy meant to my children and shortly afterwards they demonstrated their clear understanding of the nature of the problem by playing 'redundancy touch' (no returns allowed). This game is very similar to 'cheese touch', 'Jamie touch' or 'double dog poo touch'. Jamie being an unfortunate boy in my son's class. Children can be so pleasant.

On Tenterhooks

Assorted shipments have arrived and so work on the saddle can resume. You may recall that I'm following the advice of Tim, who is an expert at this stuff. The first thing to do is to obtain half a cow. And not just any old half of a cow either. I don't actually need half a cow but this is the smallest amount I can obtain directly from the supplier and I'm sure it will get used. Tim gave his recommendations for the type of leather I needed and I was almost able to obtain what he advised. The important bit is that the leather is naturally tanned (with oak bark etc.) and is suitably thick. Chrome tanned leather (most leather is tanned with chromium salts) won't do at all, it won't move enough when stretched over the block and won't retain the new shape when dried. Also the part of the animal is important too. Tim advises using the butt rather than the shoulder as it will stretch less when complete and will be more durable. Also, as every female on the planet knows, the butt is thicker than the shoulder.

Half a cow, yesterday.

My hide was produced by Chahin tannery in Mexico, it is 6 mm skirting, Tim thinks that this is too thick and has suggested ways of thinning it. Since I have so much leather, I'm going to try at full thickness first and then do it again if it doesn't work well. It's all a new learning experience for me.

The orientation of the saddle on the hide is also important, it needs to run vertically, up the animals side rather than along it's back. This is again to prevent unwanted stretch.

Brooks saddles are moulded under high pressure as in this short film at (6:00).  Do make sure you watch part two as well. Obviously my shed doesn't run to such tooling so I need to do it manually.

The first thing to do is to make the wooden block that the leather will be moulded over. When I did this previously I used one large piece of timber and carved it out. I used a lump of oak just because I happened to have it lying around. This was hard work and I wouldn't recommend it. So this time I decided to laminate the block from planks of pine, this has a big advantage that I'll get to in a minute.

Cutting out the laminates.

First mark the outline on the planks and then jigsaw them out. I used a coping saw just because I'm a retro grouch and like doing stuff by hand. Actually, I can't easily get blades for my jigsaw, it being an older model bought in England many years ago and now residing in NZ.

Glue them all together and clamp it up for 24 hours.

Clean up the profile before doing any shaping. 

I found that large metal working bastard files were better than a wood rasp designed for the job.

Then start to shape the block to match the saddle cantle plate and nose piece. 

Most importantly the the block needs to be a shape that you think will be comfortable to sit on. After so many miles cycling, I happen to know reasonably well what that means for me. That shape is not a simple triangle with folded over edges. The sides of such saddles tend to dig in most painfully. This is where the laminated construction comes into it's own, the lamination lines make it easy to see when you have both sides the same.

Finally when you are happy with the shape, varnish the block to protect it from moisture. 

A Brooks B70 has deep side flaps so I made my block quite deep to allow for this.

Now we need a way to stretch the leather over the block. When I did this previously I punched a series of holes around the perimeter of the leather and then threaded cord through the holes. By using a series of wedges I was able to tighten the cord. This wasn't very satisfactory and the tension in the cords wasn't easily adjusted. I hit upon the idea of using adjustable tenterhooks. Once again punch the series of holes around the circumference and then screw a series of wood screws around the base of the block. The leather can then be stretched by threading zip ties through each hole and around a screw head.

Tenterhook tensioning technique.

Next dunk the leather in some warm water. You will see air bubbles rising out of the edges and face of the leather, You need to keep it in the water until all the bubbles have stopped and then a bit longer for good measure. I left it in for an hour as Brooks do but that is probably overkill. When you take the leather out of the water it has a rubbery, gooey feel to it.

So now strap it down onto the block with the zip ties, it is possible to massage the leather down to conform to the shape of the block and then tighten the zip ties to hold it in place. Due to the thickness of the hide and the three dimensional nature of my block this is not a quick process and it is quite hard to completely remove the bulge on the top of the saddle. It would probably be easier with two people. One to massage the leather down the sides and the other to tighten the straps at the same time.

I'm going to buy shares in a zip tie company.

This whole process took me an hour and a half from getting the leather out of the water to having the leather tightly conforming to the block. Tim has recommended a specific type of dye to use when the leather is still wet, so the next step is to make a dauber (I made it earlier from cotton wool wrapped in cotton cloth) and give the saddle a number of coats until the desired colour is achieved. Then leave it to dry.

So far so good, but now the skilled bit starts.

To be continued...

<out of character rant>

In other news, we have had two cyclists killed this week in Christchurch. My thoughts are with both families, really they are. In recent months I've started to notice a worrying tendency for the press to report on the clothing choices that dead cyclists make. In both cases the cyclists were wearing helmets which is a legal requirement here in NZ, this was duly reported. Also noted was the fact that the cyclists were not wearing high visibility clothing. It appears to be a subtle shift in the blame process. Note that both collisions, I won't call them accidents, were in bright daylight in dry conditions and within 1 km of each other. The cyclists are effectively being partially blamed for being killed by not dressing like a Christmas tree. Do all cars have to be painted bright orange? Is the colour of cars involved in collisions noted in the press? With all the post earthquake roadworks, demolition and building going on in Christchurch, at least half of the population of the city and most of the road network are swathed in bright orange traffic cones and high visibility jackets. This has become the new normal and consequently a cyclist does not stand out anymore.

New Zealand driving standards are very poor when compared with developed countries. Factor in the national sport of drink driving and you arrive at the shameful road toll that we have. Until people start to drive with some awareness and empathy, things will not improve.

I'm not holding my breath.

</out of character rant>

The Tension Mounts

As promised, I've been busy making the tensioning hardware for the saddle this week. I am fortunate in that I have a Brooks saddle from this period in my possession so I have been able to make exact fac similes of the components relatively easily. This is convenient because I had a brain fart and neglected to take any measurements of these bits on the original.

 Too much tension, or more likely just shrinkage from 125 years of neglect 

has caused the original leather to part company at the nose piece.

Lots of photos but no measurements. 

Unfortunately, this week I did the exact opposite, I took loads of measurements but no photos. So you'll just have to look at the finished bits and imagine the steps involved. Sorry about that.

 Some fiddly filing fun.

 I have some nice copper rivets ready for these holes.

Now that the saddle frame is finished, I'll probably

 make  a new seat post at the correct angle this time.

The camera has made it appear worse than it is.

I still need to polish and plate all the saddle stuff which will take a little time, then I need to have a little think about what to do next.


In other news, it is with some degree of sadness that I must report the death of the pub argument. I am a member of a pub quiz team, quite a successful team as it happens. But that is incidental, the pub quiz is merely an excuse to go down the pub and talk nonsense and escape from reality for a short period of time. Our particular pub quiz only actually runs during the winter months, however we still attend the pub on 'pub quiz nights' throughout the year. We have a loose collective of professional members and whoever turns up turns up. It is suspected that certain members have not told their respective wives of the winter only thing. As a team we can generally clean up on the 'real' questions on science, geography, literature, proper sports, decent music from our youth etc. However, we are utterly hopeless on the 'fluffy' questions. Who won American 'X' Factor Idol Got Talent last year? Not a clue. I hesitate to suggest that it may be because we enforce a strict 'no girls allowed' rule.

In these off season evenings certain topics come up from time to time that cause discussion, sometimes heated but always cordial and enjoyable. Classic pub arguments. These would often last until the next week when somebody would have looked it up to prove the point and get a free pint. This is now a thing of the past, what happens now is that somebody whips out one of these modern "electric smart phone" devices and the prosecution rests m'lud. Not as much fun...

Front Saddle Mounts

As mentioned last time, I've spent my shedweek making the front mounts.

 I've never seen front mounts like these before. 

They match the catalogue illustrations, so clearly the original saddle and worth copying.

These are tricky little blighters with lots of angles and sticky out bits and holes and stuff. After a little planning (read trigonometry) I calculated that I could just get them out of a piece of 1 1/8" bar stock if I was careful and had a bit of a tailwind. The mounts have angled holes and faces in multiple planes which means that I need to machine the containing shape out accurately before drilling and tapping the relevant holes. Only when this is done can I then smooth out the angles and make them appear more organic. The originals would have been castings with very little clean up.

My new milling machine got an extensive trial this week, I'm still learning the best way to use it with the tooling I have available to me. Also I spent quite a considerable period of time making the thing run a bit more quietly. This is a known issue with the Mk1 Dore Westbury mills. They have an epicyclic gearbox that uses straight cut Myford change gears that are noisy in use.

Initially I machined the angled flats by using a Myford swivelling vertical slide, but after a period of time I realised that I could get the same results with more rigidity if I just used a machine vice and set up the work with a combination square with a protractor head.

A series of photos will illustrate the process as usual.

 Mill flats on either side of the bar stock.

 Mill the angled faces using the swivelling slide.

 And again.

 Before I ditched the swivelling slide due to clearance issues 

and just used a combination square to set the angles.

 Mill another flat on the side.

 Mark out and cut the two halves. 

And now mill faces in the other plane.

Hacksaw off some excess...

... before milling to size.

 All the faces are now done, so I can drill and tap the

 holes at the correct locations and angles.

 Starting to clean up with a file.

Beginning to take shape.

A little more  thinning is still needed before I'm happy.

Next week I'll start on the saddle tensioning components.

In other news, the whanau have left me and gone to visit relies in Australia for the week, Whilst they have gone we have had 30+ degree days and bush fires. Honestly what has 'stralia got that you can't get right here in Canterbury. A few weeks ago I even saw a wallaby at the side of the road as I was cycling home. It was just at the Tram Road and Northern Motorway intersection. I know that they occur down in South Canterbury but I never seen one this far North before. I know for certain that it was a wallaby because I was able to watch it for a long time without it running off. In fact I would have been greatly surprised if it had run off since it was dead. I looked it up and apparently it is a Red Necked or Bennett's Wallaby. It is of course possible that it was killed down South and inadvertently or otherwise carried North. It wasn't there the next day so it was probably just resting or something.

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.