1. I rely on one bike as my main form of transport. If it breaks or I need to do some work on it, I haven’t got another bike to ride.
2. In my experience, some staff in bike shops aren’t very helpful, give the wrong advice or are too busy to help you. I decided it was time to learn how to build and maintain bikes myself. I’m sure that there are many very good bike shops around, just not in my area.
3. My other bike, a Charge Tap, is a great street bike but it’s not so great in wintery conditions. I wanted to build a simple, low maintenance bike that I didn’t have to worry about too much while riding in the winter months.

So, having recently finished building it, I thought I’d share what I’ve learned with the hope of helping others thinking about doing the same. I should add I’ve been hugely inspired by the late Sheldon Brown and his excellent online resource for bike maintainers.

Frame & Forks

I wanted a light-weight frame on which to base my bike. There are plenty of frames for sale on eBay, but finding a decent one that’s suitable for a single-speed can be tricky. Single-speed and fixed wheel bikes have horizontal dropouts to allow the back wheel to move backward to keep the chain tensioned. However, unlike vintage road frames popular with fixie and single-speed riders, many newer mountain bike frames have vertical dropouts, meaning that you can’t tension the chain without a tensioning device (essentially a jockey wheel and a spring that hangs below the chain stay).

As I wanted to keep the bike as simple as possible, I decided to look for a frame with horizontal dropouts instead. There are two options here; you either look for a newer low-end frame (many Raleigh and Peugeot frames from the 90s have horizontal dropouts) or an older but better quality frame from the late eighties and early nineties (early frames from Specialized and Trek had horizontal dropouts). If you’ve got a bit of money to spend on a new frame, manufacturers like Surly and On One make new frames designed specifically single-speeds and bikes with hub gears.

I managed to find a 1993 Specialized Rockhopper frame on eBay that came with forks, headset, stem and seatpost, all for £16 (although not including postage!). It’s best to try and find a frameset as complete as possible, mainly because the steerer tube on the forks is cut to fit the headtube and headset, which can be an arbitrary length depending on the size of the frame. Also worth noting is that headtubes either fit a 1″ or a 1 1/8″ steerer tube; older frames tend to fit a 1″ threaded fork.

Wheels

I bought a pair of second-hand but hardly used 26″ Vuelta wheels complete with shimano cassette hub, chunky tyres and tubes, for about £25. To convert to a single-speed bike, you’ll need a conversion kit, which is a single sprocket and a set of spacers which replace the cogs (cassette) on the rear wheel. The conversion is quite an easy job with the right tools: a lock-ring remover, chain whip and adjustable spanner.

Gearing

With a single speed bike, it’s important to get the gear ratio right depending on the terrain you’ll be cycling on. My bike is intended as a street bike with occassional off-road use on bridle paths. If you look up gear ratios for a single-speed mountain bike, many suggest a starting point of 2:1. The sprocket that came with the conversion kit was a 16 tooth, so to get this ratio I would need a 32 tooth chainring. This ratio is rather low; for every rotation of the crank, the rear wheel goes round twice. It’s good for hill climbing, but not so good for riding on the flat as you’d be pedalling like crazy. So I decided to get a 38 tooth chainring with the 16 tooth sprocket, this gives a high enough gear to cruise along at a moderate speed, but low enough to get up those hills… unless it’s really steep.

Bottom Bracket

Some second-hand frames are advertised with an old bottom bracket already installed. While this may be tempting to save installing one yourself, it’s really best to get a frame without a bottom bracket. You don’t know what state it’s in, and worse, it might be seized to the frame leading to potential thread damage when you try and unstick it.

With the right tools, dealing with bottom brackets is quite straightforward, as they’re mostly sealed units that screw into the frame (although do note that the right side of the bottom bracket tends to be reverse threaded). There are a few different types that need to be considered. I decided to go for a standard square tapered bottom bracket, which some now consider to be the old fashioned type, ISIS having become the more popular standard. There’s also Octalink, Hollowtech or X-type bottom brackets, which seem to be an attempts at manufacturer lock-in to BB/Crank combinations.

Square tapered bottom brackets are cheaper but very robust, and fine for my requirements so I went for a Shimano UN54. Most frames take either 68mm or 73mm width bottom bracket depending on the width of the shell. The length of the spindle varies as well; for a mountain bike, you shouldn’t go too far wrong with 118mm. However it’s worth checking which length spindle is most suitable for your choice of crankset.

Crankset

Most right-hand crank arms are either all-in-one, where the crank arm and chainring are one unit, or you can buy the crank arms separately and bolt on a chainring. I recommend the latter option because it allows you to be a bit more flexible about the gearing. Also, this is the one component of the bike where I didn’t scrimp on second-hand parts because they need to be strong and reliable, especially on a single-speed where up hill riding requires a lot of force to be put on them. Most crank arms connect to the chainring with either 4 or 5 bolts at a varying diameter called BCD (Bolt Circle Diameter). You just need to make sure that the BCD matches on the crank arm and chainring. For most mountain bikes with a 4 arm crank, the BCD is 104mm.  I bought some FSA El-toro crank arms for about £25 and bolted on an FSA 38 tooth chainring for about £15.

Chain

I went for a Charge Masher half-link chain which is designed specifically for single speed bikes. The half-links allow a little more flexibility when both adjusting the length of the chain and positioning the rear wheel to keep the chain at the correct tension.

Brakes

Originally the frame would have had cantilever brakes on it, but I decided to fit vee brakes instead. I thought these were a straight replacement for cantilevers because the frame bosses are the same for both. However, while installing them, I had a problem when routing the cable through to the back brakes. Frames designed for cantilevers have braze-ons that ensure the cable drops down between the brakes. This is no good for vee brakes, as the cable enters the brakes from the left side. So, I had to buy a clamp-on cable stop that allowed the cable to enter the brakes at the right angle.

Epilogue

So I’ve glossed over a few things, mainly the outlay on the tools needed to build the bike, and the other bits and bobs like pedals, handlebars and the £2 bell. In total, it probably cost me about £160 to build. You could ask me why I didn’t simply buy an old but complete Specialized Rockhopper for about £50 and convert it to a single speed. Yes I could have done that, but I wouldn’t have learned as much and it wouldn’t have been so much fun!

View set

With the iPad, it’s like Jobs picked up a five year old magazine article about what Apple might have in store for the future, and based their new product on that. It’s even called iPad.

Many of us who are underwhelmed, however, may remember that the iPod was met with similar disappointment (and derision for its name) when it was first released.

Or maybe we’re all just Apple obssessed idiots.

My prediction is something bigger than an iPhone (and just as thin and sleek), but no bigger than a Kindle.

In the 60s, cinema-goers got their kicks through the use of psychoactive drugs, making 3-D glasses somewhat redundant. The 70s saw advances in technology making 3-D projection cheaper and easier, which lead to the next craze in the early 80s and culminating in the ultimate in three dimensional entertainment, Jaws 3-D, starring Dennis Quaid.

The thing in common with each of these periods of popularity is that they were all short lived; 3-D projection never became the default way to experience cinema. Maybe people realised that what makes a good film isn’t a rather poor illusion of an extra dimension, but a good plot, a good script and the development of characters you care about.

On the back of the success of this film, Peter Jackson and George Lucas are said to be re-releasing their films with reworked 3-D visuals³ (I can only imagine that a 3-D Jar Jar Binks will be a third more annoying) and analysts are saying that 3-D will be the default way to see films in a multiplex cinema. I’m sure that cinema-goers in 1983 would have expected more when they future-gazed into 2010.

• ¹Comin at Ya! was a 3-D Western released in 1981.
• ² Research hastily and lazily cobbled together from Wikipedia.
• ³ Apologies for the link to The Telegraph.

This isn’t an issue for many. But it is if you’re using a development build of a browser, or you’re using a Linux distribution with a modified version of Firefox that, due to licensing restrictions, can’t use the Firefox branding. In this case, the user-agent string will contain the development name of the browser, such as ‘Shiretoko’ or ‘Namoroka’.

In Firefox, changing the user-agent string in about:config to ‘Firefox’ will solve this problem. In Chromium (the development build of Google Chrome), you’ll need to launch the browser with a command something like this:

chromium-browser --user-agent="Firefox/3.5.5" --enable-remote-fonts

Recent builds of Chromium now support @font-face, so you might not need the -enable-remote-fonts option.

Hopefully, Typekit will improve their browser detection by checking the rendering engine in the user-agent string, rather than simply the browser name.

Science as a big stick

As the opening sequences of 2001: A Space Odyssey reveal, humans have always applied our knowledge to build tools to kill for food, defend ourselves and dominate and populate other lands. Science isn’t a new and dangerous development in the history of the human race; we’ve always sought to acquire knowledge about the world in order to give ourselves a competitive advantage over others.

The fact that humans have done terrible things with knowledge is irrelevant to the fact that the truth about our world and the universe is there for us to discover, and it’s up to us to use science in a positive way.

Beyond Darwin

The notion that accepting the theory of evolution as the absolute truth in explaining our origin is somehow ’scientific fundamentalism’ is, to me, a deeply corrosive and worrying train of thought.

The theory of evolution doesn’t just stop at Darwin, his theories have been proven by the sequencing of the genome of many species including humans. We know that every single living thing on this planet shares a common ancestor, and humans are at the end of a small branch on the tree of life. It’s a fact, like the fact that the Earth orbits the Sun once per year. Those who dispute this fact are rightly ridiculed, yet, in the 21st century, 150 years after Origin of Species, and after decades of gathering mutually supporting evidence, the theory of evolution is still being disputed, and opposing ‘theories’ are still taught in schools.

Eugenics is always raised as a kind of red warning light in the discussion of the theory of evolution. It’s a bit unfortunate that it was Darwin’s cousin that started the Eugenics movement. The basis of what Darwin discovered was that what humans had been doing for thousands of years, i.e the modification of animals – in this case for our own benefit – had been happening naturally for billions of years. Galton took Darwin’s work and experimented with how disease could be selectively bred out of humans. I expect his intentions were good (if a little naive) at the time. It took the madness of Hitler to take Eugenics to the extreme of genecide and of attempting to breed a master race.

People call Dawkins a scientific fundamentalist, which, in my view is wrong. I’m going to quote this Dawkins article in the Times:

“Do not mistake passion, which can change its mind, for fundamentalism, which never will. Passion for passion, an evangelical Christian and I may be evenly matched. But we are not equally fundamentalist. The true scientist, however passionately he may “believe”, in evolution for example, knows exactly what would change his mind: evidence! The fundamentalist knows that nothing will.”

On the claim that science can’t explain everything.

I’m not sure it’s possible to make the claim that science can’t explain everything. Surely it’s like someone in the 1500s saying ‘We won’t be able to prove the Earth orbits the sun.’

If we’re talking about what explains our morality, then there’s certainly no reason to think that religious belief provides us with our moral code. The question of why cultural shifts happen, such as the abolishment of slavery and rights for homosexuals (to name but a few), is a complex one to answer. But I would suggest that knowledge has played a big part in these shifts. Surely you wouldn’t argue against the fact that hatred, bigotry and intolerance come from lack of knowledge and ignorance, and science and reason are the antidote for this?

Our social interactions are extremely complicated and a result of the complex societies and social groups in which we live. The social interactions of many other animals are also extremely complicated, but that doesn’t mean they can’t be studied and understood.

On attacking religion

If certain beliefs are causing harm to people, isn’t it our moral imperative as a society to put a stop to it? Take for example, the belief that a woman should not have the right to an abortion. The belief that abstinence should be practiced instead of contraception. The belief that homosexuals are sinners and are going to hell? Surely these harmful beliefs are borne of ignorance and should be reviled and attacked? I’m very much with Dawkins (and Hitchens) on this one.

Is it more important to be happy than right?

‘If ignorance is bliss, then religious people must be very happy” – Patrick Moore

I think I’d prefer to be happy and right. I have no formal scientific education, yet I’m now more interested in science, particularly astronomy, now than ever before. For me, finding out the truth is a deeply rewarding experience. Relatively simple things like how the tilt of the Earth’s axis combines with our orbit around the sun to create our four seasons, in turn creating the cycle of life on the planet. How gravitational forces between the Earth and Moon create the tides, and how many species have adapted to, and rely on these tides. I love to think about stuff like that, that’s my ’sprituality’, if you like.

To conclude

In my opinion, it is not reasonable to that claim that scientists are as fundamentalist as the religious leaders they criticise, and that science itself is some kind of quasi-religion. To do so is to belittle the positive things we achieved with science over the last 400 years, and the positive outcomes do outweigh the negative.

• the road to the City of Emeralds [that] is paved with yellow brick
• the one paved with yellow bricks
• the hard, yellow road-bed
• the road of yellow brick
• the path of yellow brick
• the yellow bricks