Occupational hand injury -- how to change an inner tube

 Every bicycle inner tube has it in the instructions printed on the box. Every experienced mechanic will tell you. Don't use tire levers to install a tire. If you're prying off a tire with a tube that's already punctured, levers are okay, particularly because the tire may be cruddy and the beads may be stuck to the rim. Installing, however, you risk putting a hole in the new tube if you use a tool to pry a reluctant bead over that last few centimeters of rim. Use your hands.

Your thumbs are important, but they're not the prime movers. Let me show you with this handy graphic what parts of your hand impart the most useful force.

This was from yesterday's wrestling match with a classic Wolber rim from the early 1980s. Some manufacturers seem to interpret the 622-millimeter bead seat diameter as 623.79, or maybe even 625. It isn't really, but you'd swear you were trying to put on a tire that was too small. Since these are almost always road rims for skinny tires, you don't have enough room to insert a tire lever anyway.

The bruised area indicates where the most power is applied to roll the tire over the edge. The blister and the split above it in the middle finger indicate how the pressure is applied. My thumbs are fine. Thumbs only provide stabilization and guidance, and a small amount of added force.

Interestingly, my left hand only showed minimal bruising and no blistering.

The key element is not strength alone, but directed strength. I do not have a particularly strong grip. And the technique does not usually lead to injuries like this. It does come in handy as a teaching aid here, though.

Be methodical. With the tube very slightly inflated, mount the first bead to the rim. Often, the first bead can be more difficult than the second. I've never figured out why, I've just observed it to be so. You can use a lever to pop the first bead on. For safety, you might want to pull the tube out of that section of tire before prying. Some mechanics mount the whole first bead and then insert the tube. Find what works for you.

Once the first bead is in place, push the valve stem into the the tire casing to make sure that you do not trap a section of tube under the beads at the valve. If it's a presta valve with a threaded stem, make sure that you have removed and discarded the stem-ripper nut thoughtfully provided by the manufacturer for no good reason. The same goes for threaded Schrader stems, but those are much less common. The presta stem rippers have the same thread as bolts in the brake system, so they can come in handy here and there as spacers and shims. Or you can make some nifty jewelry. Maybe hang them from various piercings. Braid them into your hair. They don't rust.

With the valve out of harm's way, push the first section of the second bead into the rim, and begin working the bead on in both directions, working toward the opposite side of the wheel. This is where you use your thumbs the most, and where the confusion sets in for the sore thumb crowd. You reach a point where it's too hard to continue by thumbs alone.

With a lot of bead on the rim, move your hands back toward the valve and place the other side of the wheel on the floor. Put the heels of your hands on the outside of the tire casing and push down hard as you work your hands down around the rim on both sides. This pushes the casing in and around, working slack toward where you are going to need it. Because wheels are round -- ideally -- you will reach a point where you can't apply downward pressure anymore. Here's the tricky bit, where you maintain as much pressure as you can while pulling the wheel up and wedging the top (valve) side into your lower abdomen, while moving your hands toward the goal line, pushing the casing and working the bead around. This ends with your hands in the grip position to roll the bead over the last bit to snap into place. You hope, anyway. You might have to work the slack around a few times before you finally get it.

Many tire and rim combinations that feel intimidating at first turn out to be quite manageable once you work the slack around. You can also let the tube get caught under that last bit of bead and use the slitheriness of the tube itself to help coax the tire over the edge. Then put the tiniest bit of air -- or just a tiny bit more -- into the tube, and pinch the casing repeatedly. The tube will want to expand into the casing. You can peek down alongside the bead to watch it retract into the tire where you want it.

Pinch and peek also describes how you want to inspect the entire circumference on both sides to make sure that the tube hasn't slipped into mischief anywhere else around the rim. Then apply pressure gradually, making sure that the bead seats securely and evenly before wailing it up to your desired max.

Rims that fit loosely to the tire are more hazardous to your hearing. If the tire flops on very easily, you need to be much more vigilant to make sure that the bead catches. Otherwise, the tire crawls off the rim and you get a blowout. Explosive failures like this not only destroy the tube, they can cause damage to the tire bead itself, so that it never will stay on. Follow your procedures. Check and double check. Inflate in short intervals.

Fatter tires may call for more thumb because they're too large and flexible to bring the power palm to bear. Fatter tires usually -- but not always -- fit more loosely, so you can work the slack around as necessary to get them over the top.

You can also judiciously sneak a thin tire lever in to help work the bead of a reluctant tire toward the finish line. The key here is never to use the levers for the final push, only to set up the final snap that you will do by hand. Be aware of where the tube is. You can push the tube further into the casing with the tire lever and then back the lever out to do the actual levering.

Tubeless tires eliminate the problems of pinched tubes, but can sometimes blow off during inflation, with hilarious results. In the case of a tubeless blowout, the entire area and any bystanders get slathered with sealant. You do need to shove a lot of air into the casing in a hurry to get the tire to snap to the bead seats, but then proceed with caution to make sure that everything stays where you want it. Some technicians recommend mounting the tire dry and then taking the valve core out to inject sealant, but it's so much easier to pour sealant into the casing with one section of bead partially dismounted. There's plenty of time later to gook up your valve stems with sealant. I've done it both ways, depending on other factors. You can still blow the tire off the rim if you get too frisky with the compressor. That I haven't done. I'm pretty cautious about blowing things up.

On the plus side, I shredded my hands last thing before going on my days off, so I have time to heal up on my own time before returning to the world of virtuous toil next week.

Trial by combat

 The weather is getting nicer and people are getting nastier. Drivers bring their prejudices with them when they crowd New Hampshire roads in the warm months. The combination of aggressive attitudes and sheer numbers raises the stress level no matter what mode of travel you choose. But on a bicycle you are more exposed and at times you are more vulnerable.

Drivers treat each other badly. Think about how many games of chicken you get sucked into in the course of normal operations. The majority of drivers may simply want to get from place to place fairly cooperatively and without drama, but embedded with them are the ones who are starring in their own private movie, and you're an extra in the chase scene. More numerous are the ones who don't mind racing in a tight field. Driver training may suggest that you leave enough following distance to avoid trouble that may pop up in front of you, but standard practice is more like drafting in NASCAR.

Driving becomes a test of skill and nerve. Drop a bicyclist into this and you generate automatic friction. The law says that drivers have to accommodate cyclists. The majority of drivers who do so varies from a slim margin of 50.000000001 percent to a sometimes hefty 98 percent. Around here, as the roads get more crowded the cooperation level drops noticeably. On open stretches of steady cruising you may only notice a few more close passes, random yells, a bit of extra diesel exhaust blurped in your direction, or a tendency for motorcyclists to downshift abruptly just behind your shoulder. But at any intersection or other flow regulation point, the cyclist enters the trial by combat.

I already mentioned the bad design of the new ramp from Route 16 southbound onto Route 28 southbound. Further down, the state put in a rotary/traffic circle/roundabout at Route 171 to reduce or eliminate the occasional bloody smashup that would occur at the old-style crossroads.

Not much of New Hampshire is flat, especially once you get away from the coastal plain. As these traffic circles become more numerous, you notice how many of them sit on a slope. It means little to a motor vehicle whether the in-run is uphill or down, unless it's very steep. You do need to regulate your speed, but you have throttle and brake that require little effort to change speed by several miles per hour on demand. Not so much on the bike. At the 171 circle, I can come into it with a gravity assist on my way south. I can snap accelerate to catch a gap and maintain a speed in the 20s easily. But in the evening, tired from a long day, I face a slight but noticeable climb into the circle itself, and have to fight gravity around that arc to continue plodding slightly uphill all the way out the exit chute to stay on 28 north. As a result, I don't usually do that.

Route 28 descends for more than a mile coming down to the flats approaching the Route 171 intersection from the south. Even a tired old fart on a heavy bike at the end of a long day on his feet can pull speeds close to 30 almost all the way to the in-run on the circle. But there the land rises, and drags the energy right out of those tired old legs. However, you learn to manage the forces of gravity and your own insufficiency. I will stay well to the right and sacrifice a little bit of speed, to encourage as many drivers as possible to go past me before we get into the confined chute. Sometimes, drivers who roared up at supersonic speeds along the straight road on the flats suddenly lose it all just when I wish they would keep rolling a little longer and get the hell past me. Now they're stuck until I finish my maneuver, but it was their choice. I always wonder if they really considered it. Worse are the ones who don't get on by, but don't back off, either.

Northbound through that circle, my standard move now is to hold off the armored cavalry as best I can in the chute, and snap a hard right to take the first exit from the circle, onto 171 east. I get an instant gravitational assist as the road drops sharply, throwing me up to about 25 mph. Even if one or more of my pursuers have come out the same way, I get a quick gap on them before the road rises just as steeply and knocks me back to the kind of speed most people consider normal for a cyclist. If it's early in the week and I'm feeling frisky I can stomp up the rise in good shape. More commonly I grovel to the top as the motorists pass with varying degrees of compassion or contempt. At least it's a straight piece of road and they're more eager to get on their way than waste time with me. I then snap a descending left turn onto Old Route 28 to merge back to the new highway in a mile or so. It's a pleasant diversion that adds very little distance and rewards a rider with a touch of tranquility.

I had a classic example of it on my ride home last night. I'm a little fried after four days of fairly hard riding for an old geezer on a utility bike. Coming into the circle I was passed by a pickup with a plow on the front, followed closely by another vehicle, with a third lining up as we got close to the entry to the circle itself. That third vehicle was determined to squeeze past me wherever we were, regardless. I slapped him back long enough to sprint a couple of yards and drop into the sharp right. He came out the same exit, but didn't catch up to pass until I slowed for the climb. Then he seemed to kick it down to a lower gear a bit more noisily than necessary. Gotta assert that dominance.

I could be a stickler for the law and cover the lane, riding into the circle and around, but I can guarantee that drivers would try to pass me at any point during that. There would be horns, shouts, anger, frustration. Vehicular purists and effective cycling instructors might say to hold the line and lead by example, because eventually the motoring public will get used to it. It will become normalized. But normalized is not normal. Normal people are self centered and self serving. Those impulses are probably responsible for 90 percent of traffic incidents. Bad behavior is constantly eroding good training, if good training was even provided in the first place.

Motorists who force bike riders to defend their place on the road do it from the safety of their armored vehicles. The drivers have nothing to lose. Even if they hit a cyclist, they usually face no penalty. They have their standard excuses, all based on the understood principle that cyclists on the road are crazy idiots who brought trouble on themselves. Our only asset is maneuverability.

Infrastructure like the Route 171 circle and the new 16-28 merge is anti-cyclist. Clearly the designers consider that bike riders are a small enough minority that we can be left to figure out our own survival strategies to get through them. We've had a lot of practice, so I guess it's true.

I do acknowledge that if the majority of motorists really wanted to kill us we would all be dead. It would be very easy, and most of it would probably be considered accidental. That's what it's called now, even if it started with a pushy driver bullying the rider, and it took a bad turn. Sorry. Breaks of the game. No driver will ever admit to the responsibility after the fact, nor will witnesses likely come forward to refute the story that will be told by the living, defaming the dead. You simply have to accept this part of the terms and conditions and put it out of your mind. Hassling a cyclist, even injuring or killing one, is like littering. It's just another technically illegal rude habit that will never lead to an arrest.

Is it Bike to Work Day?

 Nobody gives a day-old doughnut about Bike To Work Day in Wolfeboro anymore. It enjoyed a sudden burst of interest in the later 1990s, which persisted in a gradual decline somewhat into the 21st Century. The recreation department had feed stations for people biking to work and school, and handed out little prizes. It was nice. People made a special occasion of it, as you would expect in a country that disdains the bicycle as a genuine element of the transportation mix. One and done, as they say.

People who are going to embrace bicycling as transportation will do it regardless of the day. People who do it on a lark will find their one day experience to be disruptive. If your route is short and flat, yes, you can just throw some stuff in a day pack and pedal whatever you have. Then you arrive and find out how little secure parking there is, or how uncomfortable a backpack is at the distance you need to cover, or how poorly adapted your bike is to daily street use. Maybe the weather is bad that day and you don't even have to make the attempt. Better luck next year! When is it again?

When gas prices spiked in 2008 there was a surge of interest in bike commuting. It didn't last the summer, but it was intense for a month or two. People were really equipping themselves to pedal when they saw prices approach $4 per gallon in many areas and exceed it in some. But the price didn't have to recede much to get them to back into their SUVs. It could almost have been a petroleum industry experiment to see how far they could go before customers would rebel. The price hikes since then have not inspired any public interest in non-motorized transportation or other alternatives that reduce consumption. Around here, hotrodding and driving enormous pickup trucks have become a major recreational activity. The forms of cycling that attract the most followers are mountain biking, where you drive to a separated venue to ride, and ebikes, which are themselves motorized. Granted an ebike's consumption of fossil fuel is almost undetectable, but it still requires external power generation to charge its batteries. It's better than an internal combustion vehicle, but has its own considerable limitations.

When I arrived at my car mechanic's shop last night after riding over from Wolfeboro when I finished work, he looked at my bike and said, "Wow, is that thing an antique? It looks like a classic." It's a 2000 Surly Cross Check frame built up with components mostly repurposed from other bikes. The crank is from about 1991 or 1992. I told him that it will be 21 years old later this year, and it's the newest bike that I ride regularly.

"I like the old stuff," he said. "It goes and goes." I affirmed that, as any regular reader here knows I do at tiresome length. Biking is not about buying stuff. It's about using it. The simpler it is, the more use you get out of it between investments. Some people get that. Most people don't. I've given up hoping that they ever will. I just try to get through my own little journeys without getting crushed.

The NH DOT just rebuilt the intersection at routes 16 and 28, because the ramp southbound from 16 onto 28 allowed drivers to merge at too high a speed, failing to yield to traffic that had turned left from 16 northbound onto 28 South. I loved that ramp. In the car you could come wailing out of it at 50 in a pinch, and high 40s routinely. For some stupid reason, drivers making the left turn from 16 onto 28 would never accelerate briskly. You could be sure that if you let one get ahead of you, you would be behind a hot air balloon all the way to Wolfeboro. On the bicycle, the ramp was great because it had a wide shoulder and a very gradual curve, so it was easy to maintain momentum and let motorists do whatever pleased them on their portion of the asphalt.

The new ramp joins 28 much closer to the intersection, with a sharper bend, much less shoulder, and granite curbing. It is in all ways an impediment to traffic flow, no doubt intended to give the poor hot air balloonists an advantage in the motor race. It is also more dangerous for bicyclists, so it really harms no one. It would be nice if they left a strip of the old ramp as a bike route, but you know no one has thought of that at DOT.

For now, I can cut through the row of orange barrels blocking the old ramp, and use it as my private bike lane, but it will be gone soon. For now, come what may, I have to get out the door to bike to work on just another day.

Your Dream Bike Shop

 The invigorated mountain bike crowd around Wolfe City has been dreaming hard about the perfect shop, while, for the most part, driving out of town or ordering parts and watching videos to get their bikes worked on. We've seen very little of them since their renaissance began more than a decade ago. At the time, after not riding since the end of the 1990s, the returning enthusiasts came in one at a time at irregular intervals, expecting to see that we had somehow managed to maintain a state of the art department for their renewed interest, funded by a nonexistent customer base for more than a decade. That's not how business works.

Having rapidly decided that we couldn't possibly know our asses from a hole in the ground, the new in-crowd quickly turned to their own resources, like a shop owner in a neighboring town, who gave it a good long try, but ultimately succumbed to the fact that you don't stay in business by only selling to the people you identify with. Despite his considerable skill set in his own arena, he could not overcome the reality that the vast majority of bike shop income derives from recreational riders on unexciting bikes, with a smattering of other categories, and a few commuters. The balance will shift somewhat from one location to another, but you'll be hard pressed to find a shop in a rural area or a small town that supports itself mainly with the high end technical hardware lusted after by the most addicted consumers.

As of last year or the year before, I was telling people that a nice $500 bike costs more than a thousand dollars now. The quality of mid and low end componentry has plunged to shameful levels of sheet metal and plastic. Cheap suspension remains heavy, inefficient, and hardly worth servicing. The more complicated the ideal bike becomes, the more expensive, complicated, and vulnerable its low priced imitators become as well. I don't mean box-store bikes. I mean mid- and low-end name brands.

Because Wolfeboro has a little pocket of affluence, the enthusiast clientele comes pre-equipped with a sense of entitlement as they view the world around them through their bubble of financially insulated self interest. Self interest is often interpreted as economic activity that supports an individual and their chosen circle on a broad front, but in specialty retail and absorbing, expensive hobbies it is focused narrowly on creating a small world to their liking, and funneling resources to it, while they might participate in the general economy in a much more even-handed manner.

The supporters of the Dream Shop concept have focused on creating for themselves a new endeavor. They've made no positive moves so far, because a number of factors impede them. The pandemic and its shortages of bikes and parts are only the most recent impediment. Prior to that they were already having trouble finding anyone with shop experience who was enough of a sucker to be their human sacrifice and actually run the place. Once bitten, twice shy. They are further seriously hampered by the fact that most of the rest of them have no shop experience at all. And a few years as a wrench or a salesperson doesn't make you an expert.

In the 1990s, when riders would come in foaming at the mouth over something they'd just read about in a magazine (pre-Internet), my answer was, "Just because you know the latest thing doesn't mean you know everything." Because mountain bikes were still closer kin to bicycles than motorcycles, this assertion carried some weight. Now we have been through decades of "latest things," so some guy who did some wrenching five years ago will be dropping into a new and constantly changing landscape. Granted, if this former mechanic has remained an enthusiast, they will know about the newest stuff, and maybe even have dug into it a bit. But someone who has only been a consumer has no idea what circles of Hell await the owner and key staff of a bike shop in this age of throwaway products and rapid mutation.

Very recently, someone advanced a version of the Dream Shop concept that was centered on our existing business. It's all very nebulous at this point. No one is getting excited. But it acknowledges the extensive contributions that the shop has made to the community since it opened in the 1970s, and it acknowledges some of the realities of operating a completely independent, small shop on the fringes of the economy. Move our place ten miles from the big lake and it would have died in infancy, long forgotten. Even in its favored spot, the course has been mostly rough, negotiating changing fashions in outdoor recreation, and the contrast between the bustling summer scene and the small and notoriously frugal population of year-round residents.

What any dreamer needs to understand is that in order to meet the desires of the technolemmings, and still service the real clientele that actually pays the bills, the service department space will have to be large, well-ordered, fully equipped, and subsidized. I wrote years ago about how the many good sports with simple bikes, whose repairs don't eat up vast amounts of shop time and call for expensive tools, upgraded frequently, subsidize the tech weenies with their endless problems with temperamental, fashionable equipment. This is now hampered by the lack of good applicants to serve as mechanics, and commerce still restricted by the effects of the pandemic. We can't get a full selection of products in most of our departments, not just bike stuff. 

One of our excellent part-time and drop-in helpers got to experience the joys of tubeless tire problems last week. A rider came in with a broken valve stem. He was about to go riding with the kiddies, so we did a pit-crew stem change for him and sent him on his way. The next day he was back with the tire dead flat. Neither the tech who fixed it, nor I, were there, so El Queso Grande checked it in as "just worked on here, tire went flat." It looks more accusatory when it's written out than it might be when the rider returns with his tale of woe. But sometimes it's exactly that accusatory. More joys of being on the front lines of service for an expensive, complicated recreational toy.

Helper dropped in soon thereafter, and dove in willingly to figure out what went wrong. We ran the diagnostic process from what you hope it is to what you knew it would be and really don't look forward to. Tighten the stem nut? Nope. Change out the stem again? Nope. We can hear it leaking into the rim. I say it's the rim tape, which will require completely dismounting the tire, cleaning and thoroughly drying the rim, and applying new tape. We also spotted where the rider had dented the rim. I theorized that the impact could have damaged the rim floor and compromised the tape there. That turned out to be the case. So, strip the tire, peel the tape, clean and dry the rim, apply new tape. Note that the rim floor is now permanently deviated at the dent, so tape may be unreliable. Remount, reseat the beads, reinflate. We don't hear hissing. Soap water produces no bubbles. We could be good. Helper leaves to get on with one of his many other endeavors in a busy and admirably productive life.

By the end of the day, the tire was flat again. Odds are, the wheel will have to be rebuilt with a new rim, or replaced entirely with another factory built wheel. The latter option wastes more material but occupies less time. And then the tubeless setup will have to be installed. 

"Tubeless lets you run lower pressures without the fear of pinch flats," say the technolemmings. Yep. But you can still ding your rim and make tubeless operation impossible. You can also pinch flat the actual tire casing. 

This is the reality of the enthusiast shop. Helper, who is working off his debt for a Specialized e-mountain bike, put in probably three hours not curing the problem. I say this not to indict his lack of skill. He did nothing that any of the rest of us would not have done as well. It's an indictment of the technology and a warning to the dreamers. I'm sure it will fall on deaf ears.

I closed out my week with a "simple pad replacement and brake bleed" on a Trech road bike with Dura Ace hydraulic brakes. Following Shimano's own recommended procedure for that brake, I dismounted the caliper from the frame. Because the brake lines run internally, that still didn't let me get a perfect rising line to the master cylinder in the brifter body. The brifter itself had to be partially disassembled to expose the bleed port. And the handlebar stem clamp had to be undone for part of the late stages of the bleed, which meant that I had to undo the rider's GPS mount, which was blocking the four stem bolts. This is after the standard removal of the brake pads, resetting the caliper pistons, and inserting the bleed block.

They make it easy to get a wrench on the mounting bolts for that caliper, don't they?

Neatly tucked into the crook of the rear stays, the caliper also sits only a few inches from where the brake line emerges from the interior of the frame. The bleed port is on the front end of the caliper, aiming down.

I made the Bleed Board years ago for the many cases similar to this one, in which the brake needs to be dismounted from the frame to do the bleed.

After the bleed, everything has to be completely reassembled in order to find out if what felt good on the bleed block will actually feel right on the brake rotor. In this case, not so much. But by then it was long after closing time, and I still had to ride home. Another 10 p.m. supper. When I get back in the shop after the bike has been hanging for a while I have an idea for a shortcut to chase the last little air ninjas out of it.

We haven't even gotten into tooling up seriously for the smokeless moped market. Smokeless mopeds appear to be unavoidable, at least for now. When a category of technology comes to dominate your industry, regardless of whether it's a good idea, well executed, you have to deal with it.

All the time that someone spends on the delicate needs of sophisticated, expensive machinery is time that we don't have for the high volume of simpler repairs that keep the real majority of America's bike fleet rolling. This will remain the reality, no matter what the dreamers envision. You remember the sappy saying, "If you can dream it you can do it?" Yeah, that's crap. How often have you dreamed that you could fly? Then you wake up.

More tar pits than cake

 Maybe it starts with a rusted bolt, or a stripped-out socket head cap screw. Maybe a bike that was too grimy for quick diagnosis at check-in turns out to have multiple problems once the veil of crude oil and sand is wiped away. Or a suspiciously clean bike is corroded into a single block of inseparable metals because its owner has diligently hosed it off after every ride. The basic tuneup becomes a trap, capturing you for hours as you try to outwit or overpower the sticky quagmire.

A minor version would be this bike with a rear disc brake rubbing. The caliper pistons needed to be reset. To do that I needed to take the pads out. The little bolt that holds the pads in place was basically welded in there. The socket head rounded out almost instantly under the first attempts to dislodge it.

Delicate work with the drill gained me a purchase for a screw extractor.

Screw not sold separately, of course, but I found one from a different brand that fit well enough.

We can't possibly charge enough to cover the costs of some of these repairs we make to preserve the usefulness of a bike that is otherwise quite recoverable. And further time is often lost as we play phone tag to reach a customer and then try to explain what weird thing is wrong, and get authorization to fix it. In the worst cases, the tar pit opens after we've expended time and resources to nearly complete a repair before getting sucked into that "one last thing" to finish it up and clear the ticket.

Or maybe it's a simple, albeit somewhat mysterious issue that draws you in a few minutes at a time, like the mountain bike that came in during the early afternoon last Saturday. The rider reported that the chain would derail two cogs when he tried to backpedal in low gear. The bike is a Diamondback full suspension model with a 1X11 SRAM drive train.

It was never a good idea to backpedal extensively on a derailleur-gear drive train, but it has become increasingly true as more and more cogs are added, especially trying to serve a ridiculously wide range from a single chainring in front. However, mountain bikers in particular need to be able to pedal back at times, to reset their foot position for technical sections, so they should be able to get at least a full crank rotation before the inherent flaws of the system flare up. The rider said that he had formerly been able to backpedal enough, but that since he "tagged a tree with the rear derailleur" it was no longer allowing him to operate unimpeded.

To the eye, nothing looked terribly deviated, despite the tree contact. He left the bike for us to consider in due course, when it came up in the queue, but El Queso Grande thought that I might be able to kick it through very quickly, since its ailment looked to be so minor. I agreed that it would probably respond to some obvious treatment.

The derailleur hanger did turn out to be very slightly deviated. That should do it! Actually, since the derailleur is below the cassette, it would have little effect on whether the chain feeds smoothly onto the top of the cassette when the rider pedals in reverse. But maybe, just maybe, since it was the only apparent variable...

Nope. But you knew that already, didn't you?

There was a chance that the derailleur itself was bent. We've seen it before. Especially with the long, long cages needed to handle the chain wrap and cog size of super-wide gear ranges, and the intolerance of systems cramming 11 and 12 cogs into very little more than the space initially carved out for eight, tiny deviations can lead to intractable shifting and chain feed issues. But again, the derailleur is below the problem, not above it. With alignment and adjustment again dialed in, the chain still dropped.

In the process of investigation, I had to remove the rear wheel. The through axle did not want to come out. EQG theorized that the through-axle itself was bent, but it didn't seem to be. My theory is that the dropouts aren't parallel. Who knows if they ever were. The bike looked sharp at first glance, all bright orange with the brand name also in bright orange, very subtle. It could also be a way of hiding your identity so it wouldn't be blatantly associated with your crappy product. A lot of things have to be exactly right on a rear suspension swingarm and a through-axle wheel mount. It's another version of the press-in BB with misaligned bearing seats. It ain't never going to be right. Y'all had one chance to make it so, and you blew it. At least with a BB you have some chance of finding a Wheels Manufacturing thread-together unit that will put the bearings in proper alignment relative to each other, sidestepping the error in frame manufacturing. Misaligned dropouts are a tougher nut since the through-axle format does not lend itself readily to the old style of alignment tools, and materials like carbon fiber or aluminum either can't or shouldn't be tweaked.

Tell me again how much better our lives are with this temperamental bullshit?

Of course I had to have the wheel in and out of those dropouts a dozen times or more as I tried cassette spacers and different cog sets to try to coax the chain line into a more cooperative orientation. I also removed the bottom bracket -- an outboard thread-in model -- to put a skinnier spacer behind the drive side to pull the crank in a tiny tad. Can't go too far, or it will act up at the high-gear end of the range. But sometimes just a little more than a millimeter can be just enough to get by.

Not this time. Nor did any cassette yield a result worth what we would have to charge for the parts and labor. I had noticed that the original cassette had a slight bend in that 42-tooth low gear, but replacing the cassette with a brand new one with a well-made, beefier 42 produced no improvement. I put the cheesy bent one back on because it made no difference.

Bent chain links can cause no end of disruption, but this chain was neither bent nor excessively worn. Hardly worn at all, in fact. Was lack of lube making the chain less laterally flexible? You couldn't prove it by me. I juiced it right up and it still hopped off.

At the end of three hours we had disassembled and reassembled the drive train multiple times and come up with absolutely nothing billable.

The wonderful world of Internet forums had no definitive guidance. There were blessed experts who had sure-fire solutions to this problem, in the same thread with the vast majority of people who said either that you should just never backpedal because the chain always derails, or suggested trying each and every thing we tried -- all of which have worked on other bikes.

There was no obvious sign that the whole bike had been bashed out of alignment by the tree encounter. And it's true that wide-range, 1X drive trains are very prone to this problem. It's another reason that I no longer feel any sense of accomplishment when one works, only a sense of foreboding, wondering when it will stop doing so, and why.

A cake tuneup, by contrast, is one on which everything goes so smoothly that the bike is on and off the stand within half an hour. These tend to happen on older bikes that have been coming to us for years. If they were thoroughly assembled, almost nothing -- and sometimes nothing at all -- will have gone out of adjustment in a year. The same is true if a tuneup was once done to full specifications. It helps if the bike is ridden with some sensitivity to its vulnerabilities, but it can still be ridden a lot. We regularly have alumni come in who have worn the chain to the point of replacement and perhaps cooked a shift cable or two, but whose hub and headset bearings are exactly where they need to be. Locknuts are called locknuts for a reason. Or a bike might need only a genuinely simple, specific repair that works as it should. But on the whole, we deal with more tar pits than cake.