Wednesday, November 4, 2009

10 mm Barrel Adjusters

Some mountain levers come with threaded 10 mm barrel adjusters. Interestingly, these levers also seem to be the type that gets frequently run into the ground, trees or brick walls. Unfortunately, we don't stock 10 mm barrel adjusters, as they are relatively rare.

Yesterday I had a repair that needed a new barrel adjuster, but it wasn't budgeted for or ordered on the tag. The simple fix is to add a large washer to a lipped ferrule, so that the housing will be held in place and not slip down into the lever. Of course, this removes the functionality that a barrel adjuster would give, which is unacceptable in a customer application.

The kludgey fix is to slap a washer on an undersized adjusting barrel so that it can't fall through, but then the post of the adjuster can wiggle around, which is very poor form. Adding a sleeve for the post is a good idea, but because the levers are slotted you need a slotted sleeve.

My solution is to use a barrel adjuster with an outer diameter of 10 mm with helical knurling. I used a drill and a vice to drill it out to an internal diameter of 6 mm throughout its length, which also removes the threaded post. This makes a perfect sleeve for a 6 mm standard barrel adjuster, and threads in due to the knurling. Putting a washer behind the locknut transfers the force to the lever housing, so it is just as strong as the original, and won't pull through.

The cost in parts and time is trivial, and the end result has all the functionality and strength (or more) of the original.

Thursday, October 22, 2009

Bikes

I love bikes. I love working on bikes. Writing about bikes is pretty fun too. Here is the start of the tour documentation, http://bc-mextour09.blogspot.com. I've got all the twitter posts from Steve and I up, plus some other stuff. Still have lots more to put in, but, it's a start. Let me know if it all makes sense to you.

Wednesday, October 14, 2009

I'm Lazy, Sorry.

I'm really lazy. Which is why there have been no posts about my bike trip yet. Sorry.

I'm glad that I live in a world where the mascot of the Japanese Broadcasting Company, Domo(-kun), is appropriated by U.S. mainstream culture, culminating in his appearance on cups at 7-11.  Awesome.

http://kitsunenoir.com/blog/2009/10/08/domo-invades-7-eleven/

Brilliant ad.

Robert

Monday, August 31, 2009

New Life Type Stuff!

So, I have a job, and a place to live. I got both within a week of getting back to Davis, and I'm super stoked on both of them. I'm living in a house with professionals and grad students, which is cool. I have my own room, and a garage that I can store stuff in and make projects.  I got a job with B&L Bikes, as a mechanic.  It's a pretty big change to be working in a really professional shop, but it has certainly been making me a much better wrench.  Having to check other mechanics work, and have them check yours really highlights what you do and don't know.  At this point I'd say I need to work the most on speed across the board, as well as consistency. I have yet to be hit with anything where I was totally lost, but my number of jobs per day is really low. It's also a change to be in a situation where you really only want to do what is on the tag, as you are not getting paid and don't have the time to fix everything on the bike.  At the Bike Coop it was generally OK to futz around on one bike for awhile, fixing most everything, and then negotiating payment afterward. But that's not something you can get away with in a shop, particularly a busy one.

On the super upside, I have my own stand, bench and tools.  Including a truing stand.  Which is about the most awesome thing ever.  It's also really cool to have fat stacks of parts, sales people to deal with customers, and to get paid to do something that I think is pretty enjoyable.  Overall, no real complaints.

It does highlight how much more bank I could make if I had my own shop, which I sort knew with the Coop; but damn, full on shops pull down some bank.  Seriously.

Davis is also flat.  Davis is so flat that I inadvertently took Kristina on a 32 mile bike ride today, and she didn't die.  Overpasses are the largest hills for 20 miles in any direction.  This is bad, because people actually ride bikes here, which means the cops actually ticket bikers. (Of course, it supports an insane amount of bike shops, which provides me with a job.)  There has been a steady increase in traffic (bikes, peds, and cars) as we approach the start of the school year. I can only imagine how nuts the end of September is going to be.

So, I've got a job, and a place, and some free time, kinda. Perhaps there will be real blog posts again soon, and perhaps I'll get the bike trip stuff up soonish.

Robert

Sunday, August 16, 2009

The Aftermath

I've been back from the Bike Coop Tour '09 for a week now, and it's been a trip.  I feel like the tour was decades ago, just because of the amount of stuff I've been trying to cram into my days.  One of those things that I'm cramming into my days is getting the documentation of the tour digitized and presentable, my goal is to have it done by the end of the work week.  But really, 43 days worth of pictures, poorly written journal entries, and memory is a lot of data to work with.

What I can tell you now is how weird it is to be back in the "real world." By the end of the tour, you don't compare the last 40 days to the preceding years of your life, you're just thinking about the tour. But after the tour, making comparisons between how I spent the last 6 weeks, and how I spent this week is unavoidable.

The biggest change is sleeping. I've slept for not enough hours of the night starting in middle school, and really only get enough sleep when I have nothing at all happening in my life, or am sick.  During the tour I was on a relatively regular sleep schedule, going to bed around midnight and waking up at 7-8am.  Now I'm back on my insane sleep schedule, which involved going to bed last night at 3-4am, and waking up at 8am this morning. I may take a nap soon, but won't go to sleep until pretty late tonight. I blame this on A. Electricity, and B. The Internet.  Both of them let me apply for jobs, check up on friends and do other stuff late at night, when I should be sleeping.

My diet has dropped below my normal resting requirements, and far below what I was eating on the tour. I'm doing one meal a day most of the time, and feel fine. I've also only had one beer this week, which is at least a 7-fold reduction in my drinking.  I think I've lost weight this week, but can't be sure.

Then there are the little things, like seeing people around, interacting with a larger number of people each day, and being in one place.  It's a little weird to wake up in the same place, and be doing stuff in the same city area every day. It's actually mildly disorienting, although not necessarily boring, as I still have a lot to learn about the layout of Davis.

It's also nice having music again.

Sunday, June 7, 2009

Butchering a Brooks saddle

I was perusing QBP and noticed the Brooks Imperial, which is the B-17 with lacing holes and an anatomical cut out. I'd been experiencing some discomfort with my B-17, and consequently lowered the nose, which has solved the problem. Of course I now have more weight on my wrists, which is not beneficial. The B-17 was designed for setups that are bar-seat level, which being too tall for my own good, is practically impossible on my bike, particularly when I'm in the drops. Since the only apparent differences between the B-17 standard and the B-17 Imperial is the number of holes, I think I'm going to go whack a few new ones into my saddle and see how that goes. Hopefully I won't destroy a nice saddle in the process....

(Brooks helpfully has images of the Imperial from directly above, making determining the dimensions of the cut out a simple exercise in geometry.)

Saturday, June 6, 2009

Graduation from the Bike Coop

I suppose last night was the last official Bike Coop meeting that I'll attend as a part of the Coop. It's a bummer that I won't be able to keep working with at the fine folks at the Coop, and keep learning
stuff from them. Nora made a diploma for all the Coop members who are leaving, which was really nice of her. I'll be hanging mine up on the wall, right above the one from UCSC.

In related news, I'm selling off my extra stuff in hopes of raising enough scratch to go on a Coop bike tour from Vancouver to San Diego. We'll see how that goes.

Robert

Friday, June 5, 2009

Well, that's over.

Last "Gotta write this term paper in one night, lets do this, Whooo!" night of my undergrad career. I told myself I'd post the paper as motivation, so even though it's pretty dismal, here it is, the last term paper.

Telescopes have an incredibly rich history, having been influenced not only by leaps of the mind but those of technology as well. In the 401 year history of the telescope it has taken on many forms, and wildly different structures. It has also progressed from observing visible light to cover the other ends of the electromagnetic spectrum: radio, infrared, x-ray and gamma ray telescopes are now operational. All this started with a simple optical telescope, in 1608.

The refracting telescope appeared in a near mythic fashion in late 1608. Like Athena, it seemed to spring forth fully formed from the minds of a few men. In this year, three people presented documents to the effect that they had invented the telescope, or similar device for enlarging distant objects: Hans Lippershey, James Metius, and Zacharias Jensen (King, 30-32).

Lippershey is most commonly credited with the idea (King 30), and not all works acknowledge the other two men. It should be noted however that lenses for spectacles were being made for at least 80 years before this point (Willach 94). The theory behind a telescope was understood, and there was no shortage of scholars mucking about with lenses at the time. Thus, it is somewhat surprising that an otherwise unremarkable man should somehow come upon a means of making an effective telescope where so many others had failed.

His merit was twofold: he was an excellent lens maker, or was able to produce lenses rapidly enough to select only those of high quality. He not only produced the first telescope, but the first binoculars, which require pairs of identical lenses (Willach 95). In addition to his ability, he had an excellent insight: he used a diaphragm with a small hole in it in front of the primary lens (Willach 95). This seemingly trivial modification made all the difference in the world: by using only the very center of the lens, where there is less spherical aberration (distortion caused by the shape of the lens) and avoiding the edges of the lens, which tended to by less perfectly ground, the resolution of the telescope was vastly improved. This made it a useful instrument, and this was rapidly propagated. Less than a year later Galileo had constructed his own telescope and was making observations.

James Metius and Zacharias Jensen also put forth instruments, within weeks of Lippershey (King 31,32). Thiers were however of a much poorer quality (King 32), and were perhaps copies of Lippershey’s original. (Adding a diaphragm is an obvious alteration, and an easy one to make once it is known of (Willach 95).) It has also been noted that Jenson was a counterfeiter of coins (perhaps also telescopes), and ended up fleeing the country to avoid prosecution (King 32).

The refracting telescope uses lenses as its optical element. It was the state of the art in optics manufacture at the time, but several physical properties of the lenses limited the telescopes. First, lenses are subject to spherical aberration (fig. 1). As light enters the lens, it encounters the surface at a steeper angle as it approaches the edge. This causes the light at the edges to be focused in front of the light from the center, making it impossible to achieve focus using the entirety of the lens. As it noted earlier, a diaphragm that limits light to the center of the lens alleviates this problem, as does reducing the curvature of the lens so that the variation in the incident angle of the light is less. However, reducing the curvature of the lens increases the focal length of the lens, requiring a much larger instrument. Chromatic aberration is another issue with lenses made of a single material: Light of different wavelengths bends at different rates in a given material. This has the effect of focusing different colors at different points, separating them out as a prism does (fig. 2). This effect would appear as a colored halo around the object being viewed, and interferes with good viewing. Again, the flatter a lens is (the longer the focal length) the less this effect is noticeable. This is why light passes through a window undisturbed, but a prism has the effect of separating light.

These limitations required that telescopes be very long relative to their diameter. Instruments that were capable of resolving the moons of Jupiter needed to be about 30 feet long (King 36) and ranged up to 150 feet in length (Hoskin). Johannes Helvius created his 150 foot telescope and suspended it using a mast and a collection of block and tackle to raise and lower it (Img. 1). One can readily see that it would be incredibly difficult to properly align this telescope, and to track objects with it. Furthermore, the lens diameter was still very small, less than a foot. By having such a small aperture, a very small amount of light could be received. Modern telescopes have an effective aperture that ranges from a few inches up to ten meters. A larger aperture allows you to see fainter objects, assuming that the quality of the rest of the telescope remains the same. This was simply not the case for refracting telescopes of this day, and despite Galileo’s forays into lens making, he was unable to significantly improve the design.

Despite these limitations, these telescopes opened up an entirely new world of observation. In his first year with the telescope Galileo made a number of key observations. He saw four moons around Jupiter, the craters of the moon, the motion of sunspots, and the millions of faint stars that form the Milky Way (King 37, 39). He also observed the rings of Saturn, but lacked the resolution to discern that it was a flat ring, and not a part of the planet itself (King 38). Galileo’s observations through the telescope reinforced his attacks on geocentricism, and certainly contributed to his disfavor with the papacy. The refracting telescope would remain the cornerstone of observation until 1663.

Mirrors a so commonplace now that we rarely give them any thought. Yet the bathroom mirror in your house is far superior to anything available to scientists in the 18th century. Mirrors were produced from polished metal, and so the reflectivity of the surface was limited to how well one could polish a given metal. Speculum metal, a alloy of copper, tin, zinc and arsenic was the standard for mirrors (Manly 3). This alloy had a high reflectivity and was stiff enough to hold its own weight. Unfortunately, it still only reflected 40% of the light that it receives, a dismal percentage (Manly 22). In certain formulations, such as the one that Newton devised, the reflectivity was as low as 16% (King 77). In comparison, the Gemni telescopes on Mauna Kea were recoated recently, and obtained a reflectivity ranging from 93-98% in the visible spectrum (http://www.gemini.edu/node/110). Speculum metal also tarnishes quickly, requiring a resurfacing every 2-3 months (Manly 22). In large reflecting telescopes, such as the 40ft reflector that William Herschel made, the mirrors could weigh over a ton, making removing them for polishing a harrowing experience (Manly 22). Despite these limitations reflecting telescopes had some great advantages over refracting telescopes.

Reflecting telescopes could be made much shorter for a given magnification: Newton’s first reflector was 16 inches long, but had a magnifying power greater than that of a four foot refractor (Watson 129). The Newtonian reflector used a simple spherical primary mirror, a flat secondary mirror, and used a convex lens in the eyepiece (Fig. 3). Newton felt that this gave a better view, as it was easier to make a flat mirror and focus using a lens. Many smaller commercial telescopes still use this design, as it is relatively straightforward. It also places the eyepiece towards the top of the telescope tube, which is advantageous for smaller (tabletop sized) telescopes as it alleviates the need to stoop down. A contemporary of Newton, Cassegrain, produced a design that placed the eyepiece at the rear of the telescope, using a second parabolic mirror to send the light through a hole in the primary mirror (King 75) (Fig 4).

This arrangement had the advantage that the concave and convex mirrors reduced the aberration experienced, but suffered from the fact that the parabolic mirrors needed could not be accurately ground at the time (Watson 131). A similar design, by James Gregory failed for the same reasons (King 71). It used a concave secondary mirror rather than the convex that Cassegrain utilized (King 71). This had the effect of requiring a longer telescope, as the secondary mirror had to be placed beyond the focal point of the primary. In contrast, the secondary mirror in Cassegrain’s design is placed roughly halfway to the focal point of the primary. In this way Cassegrain found a very elegant design, which has become the basis for almost all modern reflector telescopes (Watson 131).
Newton was a vocal opponent of Cassegrain’s design, and as such very little work was done on it until mirror technology had advanced sufficiently for high quality parabolic mirrors could be produced.
It would be an error to leave William Herschel out of any dialogue on reflector telescopes. If a patron saint of polymaths were to be elected, he would certainly be in the running. Self taught in astronomy at the age of 35, Herschel chose to survey the sky, and became and avid collector of stars and nebulas (Cambridge 235). He also designed and constructed his own reflecting telescopes, up to a 40 foot-long reflector with a four foot primary mirror. It differs from all other reflectors so far mentioned, in that it has no secondary lens. Rather, the primary lens is viewed from directly from an eyepiece set in the side of the telescope tube (Manly 22). By reducing the number of optical elements that the light encounters Herschel was able to achieve a much brighter image than would be seen in a comparable Newtonian (Manly 22). Due to the size of the 40 foot telescope, Herschel rarely used it, preferring to use a 20 foot telescope of the same design (King 133). However with these smaller instruments, Herschel was able to first observe Uranus, and speculate extensively on the composition and location of nebulas, discovering 2,500 (Cambridge 240). His sister was instrumental in assisting him in his efforts to categorize nebulas, but was also an astronomer in her own right. She used a wide aperture low magnification telescope to search for comets, of which she found eight (Cambridge 232, Watson 178). The telescope that she used would have been difficult to make as a refractor, as the lenses available would have limited her to a narrower aperture, a detriment when attempting to scan large sections of the sky.

Herschel’s work on nebulas was continued by William Parsons, who was equally seized with a fascination with large mirrors. He constructed a massive reflector, using a 6 foot primary mirror (Cambridge 253). This impressive instrument allowed him to see the spiral structure of M51. His sketch of the nebula as compared to modern photographs is incredible, and a great improvement over previous drawings of the same nebula (Cambridge 255). See Images 2 and 3.

It was about this time that the refractor began to advance again. Newton’s theory of light seemed to squash all hope of rendering a lens free of chromatic aberration. In a calculated move against public opinion, various people experimented with lenses, attempting to circumvent the issues which had plagued refractors in the past. Leonhard Euler provided a theoretical basis from which John Dollard experimented with achromatic lenses (King 147). Initially these attempts used water between two glass lenses, however these were very high in spherical aberration (King 148). He then hit upon flint glass, which is has a higher refractive index than ordinary glass or water (King 148). By combining a series of flint and crown glass lenses he was able to produce the first achromatic lenses (King 148). His son John went on to produce and market these lenses, but the general state of glass making limited the size of lenses to about 5 inches (King 150, 176). Pierre Guinand would next advance lens making, by increasing the ability to produce high quality glass.

Lenses above 5 inches generally contained imperfections which rendered then unsuitable for good viewing (King 176). Pierre Guinand’s method of creating high quality flint glass enabled the production of full 9.5 inch aperture refractors (King 178, 180). The Dorpat refractor constructed by Fraunhofer in 1824 is considered the first modern achromatic refractor, and is an impressive telescope. It was clever in all ways, being not only optically fine, but utilizing a equatorial mount and counter weights which allowed it to be moved quite easily despite its 14 foot length (King 182-183). In this way the Dorpat refractor serves to illustrate the resolution of all the issues that the refractors of Galileo’s period suffered. Being of a manageable length and mounted in a way that facilitates observation, and having a set of good achromatic lenses it could give reflectors a run for their money.
Fraunholfer’s contributions ran far deeper than his telescopes however. He invented the spectrometer, which may be the single most important piece of equipment that has been attached to a telescope. Not only does it allow for determining the composition of various luminous objects, the matter that we cannot see between us and said luminous objects, the composition of out own air, it also allows us to determine the speed of objects relative to us. Unfortunately he was not as interested in the spectroscope as in optics, and so he did not expand it to its fullest potential. He did however note the absorption spectrum of the Earths atmosphere. The lines that he noted and lettered (Img. 4) are still known by his name (Watson 238).

In 1864 an amateur astronomer named William Huggins, armed only with a modest refracting telescope and a spectroscope solved a question that had baffled even Herschel. Are nebulas amorphous collections of gas, or are they aggregates of stars that are too dim to resolve? The answer is yes. Huggins looked at the spectral lines for several nebulous objects and found that the diffuse objects had a defined, narrow, spectrum, indicating that they were illuminated clouds of gas (Watson 239). In comparison stars had a more complex emission pattern, which one cold see by taking the spectrum of various stars. By doing this Huggins also established that the elements present on Earth exist throughout the visible universe, thus proving the common chemistry of both (Watson 238). He is credited with starting astrophysics, and popularizing one of the most useful tools we have in conjunction with optical telescopes.

As refractors continued to improve, the theoretical limit for their size was eventually found: as lenses increase in size, they begin to sag. This is particularly an issue for lenses, as they have to be suspended by their edges which out of necessity leaves the center unsupported. It seems counterintuitive that glass should sag, but it certainly does. If you have the opportunity to manipulate a large plate glass window its flexibility will be readily apparent. This limits lenses to about 40 inches in diameter, a size which was achieved in 1897 with the Yerks refractor (Watson 244). A 48 inch refractor was completed for the Paris Exposition Universelle but it was decommissioned after the end of the exposition (Watson 245). The second largest refractor in the world today is the refractor at Lick, measuring 36” and completed in 1888 (Watson 243). The refractor at Lick is not only notable for its size but also its location: it was the first mountaintop observatory in the US (Watson 243). The shift to mountaintop observing reflects the increasingly institutional method of astronomy, with the scientific community forming and specialization with in it becoming the norm. The need for better seeing resulted in the use of mountaintop observatories, which were possible due to the institutionalization of astronomy. This is a notable departure from the majority of astronomical observation using telescopes: as can be seen with Herschel, Galileo, Huggins and Newton, it was the case that telescopes were built where the scientists were. Now it is quite the opposite!

Reflectors were certainly not left out of the turn of the century surge. A new method for producing mirrors was discovered: the chemical deposition of silver onto glass (King 262). This produced a mirror with much higher reflectivity, into the 90% range, making it more than a 100% improvement over speculum metal. The glass used is easier to work with than speculum metal, and significantly lighter, and replacing the coating can be done chemically rather than via regrinding the mirror (King 262). This method is generally so superior that all large telescopes are produced with some variant of this process, and such that the cutting edge telescopes produced today are large reflectors, ranging in size up to 10m. Bear in mind that that is ¾ the length of some of the larger telescopes that used speculum metal.

Lastly, there is a telescope about which few people know, but which is particularly interesting. The zenith telescope utilizing a mercury mirror is a particularity in the field of telescopes. Much work goes into making sure that the mirrors are aligned and stable, and are designed to have rigid mirrors to give the best viewing. Thus it is a bit counterintuitive that mercury, a fluid, should be used as a primary mirror. But when placed in a shallow rotating pan, centripetal force causes it to assume a parabolic shape, the depth of which corresponds to the speed of the rotation, and is independent of any small defects in the pan (Manly 12). This method is limited to pointing vertically, hence its use only in zenith telescopes, but is an effective solution.

In the past 400 years telescopes have evolved from very primitive tools to incredibly sophisticated devices. They have consistently remained on the leading edge of technical innovation, even spurring it in some cases. Over the years the nature of astronomy as a discipline has changed as well, from being a hobby of those with the intellect or means, to a formal discipline within the scientific community. (This was a general trend in all fields.)

Works Cited

Hoskin, Michael. Ed. “The Cambridge Concise History of Astronomy” Cambridge University Press, 2008.

King, Henry C. “The History of the Telescope” Sky Publishing Corporation, 1955

Manly, Peter L. “Unusual Telescopes” Cambridge University Press, 1991

Watson, Fred. “Star Gazer: The Life and Times of the Telescope” Da Capo Press, 2004.

Willach, Rolf. “The Long Road to the Invention of the Telescope” American Philosophical Society, 2008

Website of the Gemini Telescope, http://www.gemini.edu/node/110, accessed 6/5/2009


Figure 1. Public Domain, Mglg, uploaded to English Wikipedia, retrieved on 6/5/2009

Figure 2. Public Domain, Lucas V. Barbosa, uploaded to English Wikipedia, retrieved on 6/5/2009

Figure 3. Public Domain, Tmoore, uploaded to English Wikipedia, retrieved on 6/5/2009

Image 1. Copyright status unknown, assumed that it has lapsed into public domain. Author Unknown.

Image 2. Sketch made by Lord Rosse of the Whirlpool Galaxy in 1845, lapsed into public domain in the United States. Retrieved 6/5/2009.

Image 3. Author: NASA and European Space Agency, Jan. 2005. Public domain with attribution. Retrieved 6/5/2009.

Friday, May 22, 2009

Protests at UCSC

There are a lot of protests at UCSC.  I would guess Cal has more, but I'd say that UCSC is at least second in rate of protests.  Many of these are organized by students, which is good, I like it when people take initiative.  Unfortunately they tend to be a bit silly, or at least misguided: When there is a protest every other week, you have to have a really huge protest to get anyone's attention.  Most UCSC protests don't pull the kind of numbers that they really need, by about a power of 100.  200 people at a protest is great, but we have classes bigger than that.  The recent budget issues have prompted a uptick in student protesting, not to mention it's the spring, so the weather is good enough to march around again. Many (several?) of the recent protests have featured a dramatic but counterproductive (in my opinion) tactic: the walkout.  While it may make a statement to your professors, it really doesn't hit the university where it hurts.  The UC system could care less if you are in class or not, you already paid them.  Furthermore, you're missing a class that you are at least hypothetically in to learn something.  Chanting about accessible education while squandering your opportunity is a little two-faced in my book.

I have a solution to this, and I promise it will work: this is a sure thing.

The reverse walkout.

Go to all the classes you can.  Do all the homework. Take all the tests. Do well, learn interesting things.  Be a respectful student. Be a well-rounded student (we need more scientists that can write well, and more writers that understand science).  But don't pay your reg fees.

As so many people have been yelling recently the UC is a corporation.  It needs your money, tax money, and private donations.  It wants your money. The UC system is like the Cookie Monster but it wants cash.  Education isn't necessarily it's primary goal.  But you can vote with your money.  Don't attend a UC.  Or don't pay the UC if you do attend.  Tell other people not to go to the UC if you feel that strongly about it. This would cause a much larger reaction from the UC, which is used to having students protest fee hikes, but is not used to having people actually learn.  And heaven forbid they learn for free.  Think about it guys. I'd love to see people learning and the UC not making money off their desire to gain knowledge. 

(Because we're all here because we want to learn, not because you get a shiny degree at the end with UCSC on it, right guys?)

Saturday, April 18, 2009

Teaching and Learning

I'm teaching a UCSC class on the Bicycle and Culture with some other students this quarter, and I'm finding it very interesting.  I've done a bit of public speaking in the past, and have taught people when I was in 4-H, but this is something else entirely.  It's such a multilevel, many headed operation that it's really a mind bender at times.  We're dealing with students who are essentially our peers, a group of student teachers who are all peers, a faculty adviser, and through him the university hierarchy.  In working with all these people and groups, there are a lot of goals that we are expected to hit, and sometimes the disjoint between goals, expectations, and reality is hard to negotiate.  For example, we would love to go to a city council meeting about bikes, but it's double booked with a lecture that has a guest speaker.  Is our teaching more important, or is showing them how activism works, and interacts with the governmental process more important?  It's a very simple question for me, but with each person you add in the decision process, the question becomes exponentially more complex.  How these decisions ultimately get made is very neat, and makes me want to go study a bunch of similar situations.  I suspect that very similar patterns of thought and archetypes will be displayed across similarly sized groups (5<N<15).

It has also been proving a good touchstone for my people skills. (Which is a lame term.)  According to the feedback I've gotten from my co-facilitators, I'm not terrible at public speaking, and can write a lecture.  It has shown that I need to work on the structure of my talks a bit, and do at least one verbal run through of the whole talk beforehand.  I felt like I missed a few points that I really wanted to hit, and repeated myself on some points.  I'm having a really good time interacting with our class though, and in particular my section.  For the most part everyone seems motivated, and happy to be there, which makes my job much easier.  Compared to leading the paint crew (which didn't always want to be there) this class is much easier to lead.  The planning is significantly more complex though.

Robert

Tuesday, April 7, 2009

Converting a French Tandem 28mm headset to 1 1/8"

Headsets, stems and the frame all have to fit together accurately to work well.  Unfortunately, standards have changed frequently over the past 30 years, as the threadless headset was introduced, and France got with the program and adopted international standards.  Another unfortunate part of this is that many french built bikes were imported into the US, and so it is very possible to come into possession of a bike using french standards. (Doubly bad because some of the french bikes are in really good condition, and are pretty nice frames, for being 30 years old and french.)

Recently, Kristina bought a tandem that happens to be french.  It was in overall good condition, with a few issues that some wrench time quickly cleared up.  One of the really annoying issues was that there was a ton of slop in the headset.  I assumed that the problem was simply that the headset needed to be repacked and tightened.  Kristina pulled the headset and repacked it, and I made sure that everything was clean (or rather really greasy) and tight, but the play remained.  We rode it around for the next few days, until I noticed that the slop had gotten worse on the ride into campus.  I decided that the problem was in the seating of the cups/race, the balls were too small, or that we had simply messed it up the day before.  I took it into the coop, pulled the headset again, knocked out the cups, found the next size up of balls, faced the head tube, reseated the cups, and reinstalled the headset and fork.  The headset was still super sloppy, but better than it was before.  That's when I poked around the crown race and found that it was moving just slightly, but more than enough to cause the slop. Blegh.

Pulled the headset for the third time, and pried the crown race off with a tire iron, which should be fairly impossible, as the race should be pressed (with the setting tool, and a large hammer) onto the crown of the fork.  Lo, there was a massive crack all around the crown.  It seems like someone rebuilt the crown with some JB weld or had welded to the crown and machined it back down.  At some point, the repair had failed, and the crown deformed and cracked, making it all broken and gross.  Either way, there was no way to set a race on that mess.

The coop keeps a drawer of random headset bits, and bunch of 1 1/8" threadless headsets in stock, so I was banking on being able to find a used fork and headset that would be able to fit the tandem.  And then I measured the head tube and headset bits.  According to the internet and Sheldon Brown, I was looking at the rare french tandem headset.  This is the black sheep of french headset standards, as it is not directly compatible with any other standards.  (Note: The obsolete french 1" standard is interchangeable with other 1" headsets and forks as the head tube is the same size for all.)

After some fiddling and measuring with calipers I consulted the magic chart of headset sizes, and found that the french tandem standard is very close to 1 1/8" threadless, within a few tenths of a millimeter.  The cups fit into the head tube with finger force alone and don't wobble, but they need to be shimmed up for a proper fit.  (There are some specific tolerances for press fitting headset cups, and how close these need to be in size. Park Tools is a good reference, but for 1 1/8" needs 34.0mm cups, and 33.75-33.9mm head tube.  According to the internet, beer cans have a sideall thickness of .09 )  I used a convenient beer can for this, using a single thickness with about a 2 cm overlap, which seemed to be about the right size of shim.  I made them twice as tall as the cup, so that there would be some extra to hold it in place in the head tube.  The order of operations for getting the shims in properly turned out to be super important.  For your elucidation, I have included them below.

First, clean up the shims, and grease the head tube a bit.  Hopefully this will prevent interactions between the aluminum and the steel, as well as making it easier to get the headset out later.

Stick the shim a little over halfway in.  Slide the headset into the shim, making sure the edges of the shim are flush with the flange of the cup.  The cup will be pushing the shim in, so getting everything square and aligned will make everything much easier. Press the cup in a smidgen, so that it locks in against the shim and the head tube, or else it will fall out at the worst possible moment. (Right before you get the press screwed all the way on.)

Press the cup in using the headset press.Slow and easy does it, and odds are the shim will squish out of alignment a bit.  If it gets really ugly, it's best just to stop and make a new shim, as any can protruding defeats the purpose of facing the head tube.

Now do it again on the other side.  Feel free to cry a little, and bandage any cuts from sharp can edges.

I was doing this at 3am after being in the shop for a good long time, so I might have been a little tired when I was working on this.  But it was pretty frustrating.  I think I ended up messing it up in some way twice on each cup, and having to pound them out and start again.  On the upside, the old french tandem is now sporting a nifty disk brake and 700c by 1 1/8" fork.  And the play is out of the headset, which makes it much easier to control now.  Of course, if I ever have to replace those cups, I'll be very very sad.

Friday, April 3, 2009

Wooo, Tandem

Kristina bought a tandem, used, which is ok because I happen to be affiliated with the excellent UCSC bike coop.  Turns out that's a really good thing, because in the less than a week that it's been in our lives, I've done more hours of work on it than I've slept.  A tandem is so totally worth it though.

Tuesday I spent a solid 12 hours in the bike coop.  A shifter was replaced, (it broke on the ride in) the headset removed, repacked, reinstalled, removed, replaced, removed, crown race removed, a crack in the fork found, fork replaced, new headset, new disk brake, a wheel built up, and everything put back together for the ride home. At 4am.

Kristina did a pretty nice job building up the wheel, which was impressive given that it was her first wheel.  We'll see how well it holds the true over the next while. I'll elaborate on the epic-ness that was that night of repairs, in particular the headset.  It's a random french tandem size, and people really don't make headsets for it anymore.

This is also serving as a test for the brake and fork for my cross bike (which is what those parts were originally bought for).  I figure if it can take Kristina and I pounding all over town on an heavy steel frame, then it should cope just fine with me.

Thursday, February 19, 2009

Memories... (All alone in the moonlight...)

I love email, in what is likely an unhealthy way. First, webmail is convenient: since it's in the cloud it's anywhere I am.  Second, it's a semi-permanent archive of my conversations.  As a person with a less than ideal memory,* and a preference for working from an actual document rather than verbal communication (side effect of less than ideal memory), I really enjoy having that archive.

I let my Hotmail account go for too long without logging in, and it deleted my emails.  It was my primary email address from about middle school to the freshman year of college, when gmail came onto the scene.  It's odd thinking about not having those emails to reference, even if I actually needed to do so very infrequently.  For me at least, email gave those memories a greater sense of permanence, a tangibility.  This is an absurd feeling, because emails aren't any more tangible than biological memories.

If those memories not reinforced by a digital keepsake are less "real" to me, does that suggest that I devalue the physical world in some aspects?  Or am I losing memories that are impossible to capture digitally (touch, smell, impressions)?  To be honest, I have no idea of the answer to the first question, but I do think that the answer to the second is no.  But it is hard to judge what I can or can't remember!

I would love to see a study done on the use of digital media to augment memory, and its impact.  I think the real question for me is how is it different from keeping a notebook, or using post-its.  Does using digital media make us smarter, dumber, more forgetful? (It is of course a non-trivial task to define those, let alone measure them)

*According to my work and school performance, and asking around, I have a memory that is comparable to or better than that of my peers.  Apparently I lack confidence in my memory, rather than lacking memory.  This perhaps an even more telling example of the impact of using email to remember things:  Memories which aren't as clear as the digital versions are discounted, lowering the expectations I have of my memory.  Since I certainly lack photographic recall, very few of my memories are as objective or explicit as an email or photograph, making my expectations of recall sub par.

A Collection of Idols

Apparently I'm a sucker for stuff like this. I didn't buy any of these things (other than the tiki, which doesn't count as it is a souvenir), other people hid them in my room or were getting rid of them and bequeathed them to me. I have this awkward fear that 50 years down the road I'll die, and people will wonder what drove me to amass a diverse collection of curios from around the world. So far I've managed to limit it to the top of my speaker and the Pip-Boy on my computer, but if my habit of inadvertantly collecting books is any indication, I'll soon be adrift in a plastic sea. Good times.

Tuesday, February 17, 2009

Amgen Again Again

This is the corner that we camped on, this is the racer perspective.


View Larger Map

Monday, February 16, 2009

A Day at the Races

The Tour of California came to town today, managing to slip in during a break in the rain. The Bike Coop and I watched the race on the downhill leg into Santa Cruz. They had found a spot on a descending corner, giving a clear view of about a half mile stretch. I arrived late (that is to say, not with the rest of the crew) and quite overshot the corner. I was going about 30 mph into the corner, which was pretty hairy given the radius of the turn, that it was descending, and that it had been raining.

It rained only briefly while we were out there, and we stayed up there until all the riders had passed. At that point there was a little over a 20 minute gap between the leader and the last man. We trailed the race down into town, taking advantage of the street closures. (Being able to legally run red lights and have a heard of riders take up two lanes is very excellent.) All of downtown was shutdown, pedestrians and bikes having a field day on Pacific. Downtown would be much improved it were closed to cars.

All in all it was a pretty good day, seeing a race, punting around the course, as well as getting a good road run and a wet & messy uphill fire road climb in. I've posted the pictures I took to my Flickr, but I wouldn't consider them to be stellar.

Tuesday, February 3, 2009

Shipping Containers

There is a fad in some circles right now to be "green."  Intrinsically this is a good idea, but some people go about it all the wrong way.  Shipping container houses are a great example of a failed attempt to be green. 

First, shipping containers aren't really cheap.  They are a huge chunk of steel, so even as sold for scrap they are pretty valuable.  Second, it's a huge chunk of steel.  And you're going to make a house out of it, thus removing it from any other use until the house is torn down.  Steel isn't exactly a renewable resource, I'd rather see it used repeatedly, and instead use a renewable material for houses (Perhaps wood? *gasp*).  Third, it's a poor excuse for being damn lazy. If you want a prefab house module, design one. Don't take something optimized for it's job, and make it something it isn't.

Also, does anyone else see a terrible irony in a consumer society packing themselves into a bunch of shipping containers?  Seriously.

Bike, Interupted

I now have a new left crank to replace the one I messed up.  After pulling the BB, it was pretty apparent why it failed: rather than having a continuous body, it had a separate bearing on the non-drive side.  If the left cup wasn't a perfect fit this would allow the bearing to move under load, causing the balls and races to wear faster.

Thanks to the coop, I have a new BB now, and it hasn't given me any problems yet.

I rode up to work through the center of campus, which is the first time I've done that.  I'm not sure if its a shorter ride, or if the topography works better for me (relatively short steep hills rather than a constant gradient), but it's a more pleasant ride than Hagar.  I also had an interesting encounter with a van this morning.  I don't think it was particularly life-threatening, just weird.  A van tried half-heartedly to cut me off and make a right, despite the fact that I was moving faster than them.  Normally I'd hit the brakes and let them take it, but they were moving at less than 10 mph, and looked more like they were moving up in the lane rather than making the right.  The net result was them awkwardly turning slowly into me, and me accelerating around and past them.  I'm not sure what the deal was with that.

In other news, you should pour one out tonight in the honor of Sheldon Brown.  He created a great, and highly accessible biking resource, http://www.sheldonbrown.com/ and generally did neat things with bikes.  A year ago today he ceased to be, a loss greatly lamented by the cycling community.

Wednesday, January 28, 2009

Finding Things

While I may or my not be one to toot my own horn, I try to do it in the privacy of my own home, and thus avoid sticky encounters.  In this instance, I think that I can safely put it out there without getting my head bitten off.  

I'm really good at finding things.

Last week I found a powered VGA splitter that my office, and I thought we didn't have.  I also found a jackpot of audio splitters, which I also needed at the time.  That could have just been random luck, but I do generally have an intimate knowledge of our equipment inventory.  Perhaps I'd just forgotten we had them and subconsciously was guided back to them.

Today was an excellent day for finding things, mostly in the Bike Coop.  For those not familiar with the Bike Coop, the basic signal that you are an old hand is if you can actually tell when people have moved things.  This is only a slight exaggeration.  So it was rather impressive that I was able to find a bottom bracket, a new crank, and cassette spacers today.

I also found Kristina's headlight today.

Overall, I think that my recent finding stuff ability has been a great boon, and am so excited about it that I just had to tell you all.

I'll post something meaningful in a few days, once I get my paper on "Twilight" polished up.

Tuesday, January 27, 2009

Bike 1, Robert 0

Note to self: when the weather is in the 40's, it is night out, and you are wearing shorts and can't feel your hands, it may not be the best time to pull your cranks.  In fact, one could say that it is a terrible, terrible time to be working on your bike, particularly on things that are very annoying to fix if you screw up.  Guess I'll need a new crank at some point...

Vintage Clipart


To be honest, the title of this post makes me feel slightly wrong, as it's both inaccurate and anachronistic. It also implies that art is old clip art, which it certainly isn't. It would be better described as public domain artwork from old childrens' books. I found a veritable treasure-trove of the images on Grandma's Graphics. An example accompanies this post, but it is well worth your time to wander through the site and see the variety. (The illustrations from "Alice in Wonderland" and "Through the Looking Glass" are in there as well.)

On a totally unrelated note, I'm incredibly busy this quarter. Which is both awesome and terrible. Next quarter I'll be co-teaching a class on Bikes and Bicycling, which brings me back to my 4-H roots. Good times.