New Me!
Sometime last spring, I began to notice an occasional hitch--or catch--followed by a sharp snapping sound coming from the drive train (chain, crank, or bottom bracket) of my light-weight road bike. When I put the bike on the repair stand, I could create the same effect. There was indeed something that almost locked up the drive train. If I pushed hard enough, I would hear a pop and then it would seem fixed; smooth pedalling would continue for some considerable period of time.
I couldn't determine the exact location of the sound, so I decided to just keep riding the bike. Eventually it would fix itself or something would break, and then I would deal with it. And so I churned on for several thousand miles of summer suffering, including the Big Dam Bridge 100-mile ride. I was still recording reasonably fast rides--though I had not managed anything memorable for months. Just old age, I thought to myself--nonetheless a little irked.
After we returned to the Ozarks from Bethany Beach, I found myself drained after some rather slow rides. Well, there had been the sodden weeks of rain in October, followed by lethargy during the drive out East and back. Perhaps I was just out of shape--so I rode a little more and a little harder until one day I could hardly even turn the cranks and there was a perceptible grinding noise like sandpaper rubbing across a windowpane. Finally, I knew the cause of my problems, and it wasn't just (or even primarily) that I am getting old and slow. My bike's axle-bearings were shot.
Several days ensued during which I labored to discover what kind of bottom bracket my road bike uses and what exotic tools I might need to replace it. Lurking beneath the surface was the dim worry that perhaps I couldn't replace the part at all. After all, the bike had been used for five seasons, seeing about 20,000 miles of hard use. Would I be able to get enough leverage to unscrew the part without breaking something (most likely my knuckles) or stripping the threads? Could I even remove the cranks to get at the bottom bracket?
Time and patience prevailed. From studying pictures on the web, I deduced which tools I'd need and determined exactly which bottom bracket to order as a replacement. Bike technology, like most other technology, has rapidly become complicated by diversity. This is especially true of light-weight racing bikes. The desire of weight-weenies to cut grams has led to continuous redesign of bike parts that once seemed simple and unchanging. In the old days, when I first began wrenching on my own bike, the cranks and axle were a single piece of bent, stout steel laced through the bottom bracket. The bearings were the size of large bb's and were packed into races machined into the rims of the bottom brackets. Cups slopped full of grease and threaded onto the axle held it all together. Every year or so I would have to add more grease, but the rest of the mechanism seemed immortal.
About ten years ago I had my first encounter with sealed bearings, which never need greasing--and cannot be greased. Nice! But the cranks and axle on a super-light racing bike are marvels of modern technology. The cranks are carbon fiber, making them stiff and very light. The axle has to be the stiffest part of the entire bike because of the torques to which it is subjected. That is why it was made of such heavy steel in the past. A light-weight racing machine, however, uses an axle that is much bigger in diameter (to provide stiffness) and hollow (to save weight). This very clever way of building an axle means, however, that there is less room for the wheel bearings. They are miniature bb's now; and they wear out faster than they once did, requiring that the entire part must be replaced. Thus, the classic bicycle bottom bracket was heavy and hearty, while the high-tech replacement is much more frisky and finicky. It's fast and light, but not particularly fragile. On the whole a considerable improvement. Time passes; things improve.
As it happens, I have just had another--and entirely opposite--experience contrasting old and new technology. When I was a boy and young man, eyeglasses were really made of glass. Glass is the perfect material for optics. It is hard and scratch-resistant with excellent refractive properties. That is why telescopes generally still use glass optics.
There are only three problems with glass lenses: (1) glass is quite brittle, making it easily shattered in some circumstances; (2) glass is relatively heavy; and (3) glass is quite hard, making it difficult to grind and polish. The design problem presented by these three qualities is not difficult to solve. Because glass is brittle, eyeglass lenses ought not to be too thin. But making eyeglass lenses thicker makes them heavier, so to keep the total weight down, the lenses should be kept small. Smaller lenses are somewhat easier and less expensive to grind. For centuries, then, corrective lenses have tended to be tiny--like the 19th-century pince-nez or John Lennon's granny-glasses.
Sometime after 1970, however, plastic lenses came into vogue. Plastic is much easier to grind and is about half the weight of glass. For ordinary prescriptions (not bifocals), the lenses could be ground on the premises of the optometrist, and the lighter weight gave frame designers many more options--leading sometimes to very large lenses in unusual shapes--think Elton John. Plastic is also more shatter-resistant and more UV-resistant than glass. For these reasons nearly all modern eyeglass lenses are now plastic. Unfortunately, plastic has two rather serious flaws. First its refractive properties are inferior to those of glass, so you just can't see as well with plastic lenses--especially if you have a strong correction. Second, plastic is easily scratched, and even the scratch coatings on plastic are inadequate. To the optometrists, these aren't really problems; they'd like you to get a new set of lenses every year anyway. To the purchaser, however, it is simply irritating to pay hundreds of dollars for a pair of glasses that start to deteriorate almost immediately.
This year, when I went in for new glasses, I decided to insist on glass. It was a bit of a battle, as I was forced to listen to multiple lectures from everyone in the office on the superiority of plastic. They like to blather on about the horrendous weight of glass, but their favorite tactic is to raise worries about getting shards of shattered glass in one's eyeballs--forgetting entirely that plastic shatters too and that eye injuries caused by broken spectacles are very rare. I listened politely, but I got my way. Eventually, I was allowed to pick out a small pair of frames to cradle my glass lenses. Then my frame and prescription was shipped off to an out-of-town facility that could actually grind glass.
I couldn't be happier with the result. As the photos below indicate, the new frames and lenses weigh exactly the same amount as my prior set of plastic lenses in larger frames. The optics are superb. Best of all, these lenses should last years without deteriorating in any way.
So, modern high-technology in bicycles and in bifocals is lighter, but far less durable than the older way of doing things. There may be a general principle at work here. The heavy typewriter I used while writing my dissertation is still perfectly functional, but I have half-a-dozen worthless old computers gathering dust in the closet. In some cases (eyeglasses) the old ways are better, while in others the light-weight, high-tech stuff is superb. Nothing could get me to haul out my fifteen-pound 1960-vintage portable typewriter to compose a blog when I have the option of writing on a three-pound netbook. Indeed, that old Remington weighs nearly as much as my shiny, new Motobecane SL racing bike!
One final observation: businesses love profit, and hardly anyone will promote the free solution to a problem. I've lived with severe myopia all my life, but only when I was researching this blog entry did I finally discover that in a pinch one can fashion a pair of corrective spectacles for daylight use by poking two pinholes, pupil-width apart, in a strip of flimsy cardboard! But who could sell such an item at a profit so why publicize the possibility--even though it's exactly the sort of tip that could save some camper's life after a tumble down a wilderness hillside.
Old Me
