Thursday, 14 August 2014

1000 km later

We have moved house. The blog has been inactive for a short time as I had too much other stuff to focus on. Other stuff has now mostly happened so we can continue. It's coming to the end of winter here and on the whole we've had a very mild one, it has however been extremely wet.

This was the road outside my new house in June, we had severe localised flooding after this.

On the whole though, I have been able to do some riding at the weekends and I've now put 1000 km on the facile. This hasn't been entirely trouble free but I'm pretty certain I've worked out most of the issues now. In no particular order

1) The trouser guard was constantly rattling on the backbone, the extra length of this making the problem worse. A normal length guard wouldn't have the same issue. Over time this would have had the potential to work harden the spot where it hits and cause a crack. I'm pretty confident that this style of trouser guard that loops over the tyre is only found on pneumatic examples such as the one I copied. Solid tyre examples have separate guards per side that end in little round knobs. The cushion of the pneumatic would mean less vibration to make it rattle. I've yet to make some little round knobs but I chopped off the loop and the problem has been solved. I have some little rubber caps as a temporary fix.

 Percy Nix's Knobs

Temporary rubber caps until I get the lathe set up again.

2) the american style tiring that was originally installed was a disaster, it barely lasted 300 km before it got too loose and became dangerous. I'm not sure why this was, the installer used a solvent instead of soap to lubricate when the wire was pushed through and it seems that this has eaten into the rubber and made it tacky to the touch. I replaced it with some old English style tyring that I had lying around and the problem has been solved in the short term. I'll revisit this when I wear out the current rubber. As always, it pays to do it yourself.

3) the front wheel had developed some play in its main bearings. I was greatly worried about this as I thought that the nitrided 4140 had worn through the case hardening and into the softer steel. I pulled the whole thing apart over two evenings to discover no wear whatsoever, the bearing surfaces were perfect. I was pleased but also perplexed. After much consideration I discovered that the inner bearing cones had just enough play in the threaded bearing holders to move slightly, this tiny movement at the hub became noticeable at the rim. These inner cones are prevented from rotating by 4BA grub screws that lock into indentations in the outer surface of the cone. The grub screws are large enough to prevent coaxial rotation but too small to prevent radial movement, the end of the grub screws was getting deformed and allowing the cone to move radially. The solution was to loctite the inner cones with a weak thread lock which will be easy to dismantle when necessary. 100 km later and I'm happy to call the problem solved.

4) The front brake rattle was driving me mad, everything is a very nice fit and I wanted it to be quiet. I considered making a stronger spring and also a supplementary spring but then decided to try just using a block of shaped rubber. This rubber does two things, it holds the brake lever off the head by just enough to prevent contact. It also places enough downward pressure on the spoon to prevent it rattling either in it's pivot or against the lever. It's so simple and yet it works perfectly and is very unobtrusive.

The brake and spoon are completely silent now, even over significant bumps.

5) As I've got more used to riding the bike and have done some longer rides I've slowly moved the position of the seat. It's now 1" farther forward and 3/4" higher than it was when I first put it together. I was beginning to get knee pain and this seems to have cured it. The saddle has proved to be very comfortable on longer rides.

6) I occasionally get spokes coming loose, this isn't a real problem and I'm reluctant to loctite the threads, I'll keep an eye on things and if it persists I'll go down the traditional route and user boiled linseed oil as a spoke prep.

7) Over about 40 kph (~25 mph) the bike starts to wag its tail. It's easy to control by slowing a little but I imagine it could get exciting quite quickly. I think it's probably due to an harmonic frequency and there's nothing I can do about that. I seldom go that fast that it's not an issue.

The bike is now so quiet that the only noises I can hear are the ticking of the gears and tyre noise on the road. The creaking is entirely me, I'm afraid.

I seem to be averaging about 22.5 kph (~14 mph) at the moment, that's an approximation as I don't have a bike computer. Bear in mind that all of my rides feature gravel sections of varying lengths and where I live now isn't flat. Kung Fu Pete and I are going to ride the Source to Sea in November so I need to do some actual training. I've ridden it before on a modern bike, a 1946 RRA, and the route is lovely. It starts above 600 m and more or less descends to seal level over 100 miles. The seal colony being at Cape Foulwind just near the finish. That's only a 0.4% average downhill so not as much help as you would imagine.

In other news, I no longer have a workshop. The new house has a very large garage but no separate room for the machine tools. I can either build another shed or I can carve a room out of the garage. The machinery was beginning to develop surface rust so I've had to drench everything in oil. Having an insulated room means that not only is it possible and comfortable to work all winter, it means that nothings rusts.

In more other news, I've bought another lathe. I'm so excited. My current lathe, a 1956 Myford ML7, is in almost perfect condition. Mr Middleton knew I wanted one and spotted it and bought it on my behalf without needing to ask. He knew I would buy it off him and he was right. I grew up with an ML7 so I know it intimately. During the course of the construction of the facile, I've often wished I had a little more speed, or clearance or power. I also wanted the ease of a gearbox rather than change gears. Every time a Myford Super 7 came up for sale locally, I'd go and have a look and come away disappointed. One man's idea of excellent condition is not necessarily the same as mine. Then two weeks ago I went to see the only example I've found that was worth pursuing, it's a long bed Super 7 from about 1970 with the gearbox and a host of accessories that I mostly already have. It's pretty grubby but is in very good condition under the grime. I hope to pick it up this weekend and start stripping it down. Mr. Middleton of course has first dibs on the ML7, an offer he was happy to accept. The Super 7 comes on a genuine Myford cabinet so I'm going to have more bench space as a result. It means I'll be able to make faciles twice as fast as before.