Tuesday, April 25, 2023

Bikes are everywhere. Bike parts aren’t.

Ever have one of those days where you’re occupied for hours getting nothing done? That’s most days in bike repair.

Diagnosing a bike repair requires multiple steps. What system is malfunctioning? Can it be adjusted, or is something outright broken? If something is broken, can it be fixed? If not, can it be replaced exactly? If not, can some other part fit? Is the exact part or the substitute part actually available? How long will it take to get here? What will it cost? Can I fake it with salvaged parts or widgets in the various boxes and bins we've accumulated?

Multiply the process by the number of broken parts on the bike. Add one more repetition for every additional part that turns up while you’re working on what you already identified.

A large shop, perhaps part of a chain of shops, in a heavily populated market area might manage to have a phenomenally well-stocked parts department. If a rider never leaves such an area, or only does so briefly -- and is ridiculously lucky -- they might not run into a problem with parts availability. But lots of riders live in smaller population centers or travel outside of the zone that Big Bicycle considers worthy of their attention. There are no parts stores, like NAPA, O'Reilly, VIP, for bicycles.

Mountain bikes often show up encased in dried mud. Their riders tend to delay maintenance and repair until the bike is completely unrideable. I had one this week that looked like it had been buried in a salt marsh for a couple of years. These modern marvels of trail mastery have lots more moving parts than their ancestors did in the 1990s, mostly so that their riders can propel them with less caution at higher speeds under the influence of gravity.

Road riders don't tend to bash their bikes as hard and frequently. Their bikes show up with overuse injuries because they don't take hard hits that show dramatic symptoms instantly. Shift cables quietly fray under housings and bar tape. Chains wear. A broken shift cable can jam an entire shifter. Worn chains wear rear cogs too badly to accept a new chain. Gravel bikes borrow from both road and mountain categories.

Even casual recreational bikes can be disasters. People bring in a bike they bought in 1998 and say that it's only 15 years old, and that we just worked on it recently. A check of our extensive records might show that "recently" was three years ago, and the problem it had then was completely unrelated to the one it has now. Bikes are taken for granted until they fail too completely to ignore. Sort of like cars, only without the built-in weather protection of body work.

Bicycles have always challenged mechanics with different dimensions and standards applied to overall mechanisms that operated the same way. Into the beginning of the 1980s, these were mostly nationalistic variations in thread pitch and some tubing diameters. From the late 1980s onward, these differences were mostly corporate-driven, related to indexed shifting systems. These affected whole drive trains, as companies messed with cog spacing to match proprietary click shifters.

Initially, the click systems used modified progressive levers. The lever would stop in a different, distinct position for each gear. This meant that the rider usually had the option to switch to friction shifting if the synchronization went out. So the companies had to mess with cog spacing to make the stops adapt only to their patented parts. By the time SRAM beat Shimano in an unfair trade practices lawsuit, Shimano's unfair trade practices had already given it market dominance, so cog spacing became more or less standardized on their pattern. The other format was Campagnolo's, but Campy has always been a luxury brand.

Index-only shifters make perfect adjustment and synchronization essential. A bike that was high end when new from the late 1990s through today might have eight, nine, ten, eleven, or twelve (sometimes 13) cogs on the rear hub. Drive trains have to match all the way through by brand on the more recent bikes, as SRAM and Shimano have kept the Shifter Wars raging. As with every war, the civilian population suffers much more than the actual combatants. Do you have three, two, or one chainring? By extension, front derailleur or no front derailleur? Well into the 21st Century, the sheer number of speeds was a selling point. Three in the front and nine in the rear makes 27. Three in the front and ten in the rear makes 30. But as chains got skinnier and shifting systems had to handle more chain angle, the industry singled out the front derailleur as the source of all evil. Your high end bike now will have only 12 speeds and damn proud of it. In other words, we're back to the same gear range we had in 1980 with two in the front and six in the back, only it all costs at least three times as much and is far more failure prone. Progress!

Riders mostly don't pay attention to any of this. They buy a new bike and treat it they way they have always treated a bike, expecting the same longevity and reliability. A younger rider who has only ever known finicky index-only shifting will have worse "good old days" to look back on compared to an old geezer who remembers friction shifting and well crafted simplicity, but they both can share the realization that things have gotten steadily more costly and fall apart sooner.

We haven't even talked about suspension, disc brakes, or tubeless tires yet. A guy came in with a sheared off alloy spoke nipple on his mountain bike wheel. With a tube-type tire, it's a quick and simple fix. With a tubeless tire, its a time-consuming, messy, costly process that involves completely redoing the rim tape. An air-tight seal is absolutely essential to tubeless tires. You can't maintain that if you peel back a section of rim tape to drop in a replacement spoke nipple. The guy bought a handful of brass nipples and went off to try his own luck with it. He is free to try cutting a hole and patching it afterward, and then dealing with the almost inevitable failure of that patch, leading him eventually to redo the tape completely. That requires completely cleaning and drying the rim before meticulously applying your tape of choice and remounting the old tire or replacing it because you discover that the sidewalls are too broken down to reseal. Even applying a patch won't work unless the work area is perfectly clean and dry. 

An inner tube will press a rim tape repair into place, while also not depending on it. A tubeless tire does not have that advantage. Air pressure alone will not press the patch more firmly where you want it. Air pressure alone will work its way into any area of weakness and turn it into a leak.

Every customer who comes in interrupts the flow of work already in progress -- or the treasure hunt for needed parts so that work can continue. It's not their fault, it's just how things go. Their questions need answers. Their bike or bike part needs preliminary diagnosis. It's important to share information and knowledge, but in the meantime the bike on the stand is just sitting there. And the new work probably triggers more treasure hunting for some part we either hadn't bothered to stock or just ran out of.