Monday, September 28, 2020

Fifty years of bike technology in a typical day

 This scrappy old street dog is actually only 48 years old, according to its owner, but fifty is a nice round number. And on any day we might see stuff at least that old, or older.

Looking at the Nishiki head tube badge, I didn't notice for a while that the bike was actually "Produced for American Eagle." 


Interestingly, little color accents on the fork blades are German colors, not American. There's nothing red, white, and blue anywhere on this bike, at least not all together in one spot.

Für deutschen adler?

The bike is designed for touring. Lots of people were happy to ride something like this across the continent in the 1970s. The owner said that it came with fenders and a set of lights. He did not keep those, but the bike still has its randonneur handlebars.

Randonneur bars are kind of brilliant. The tops rise from the center and are sometimes swept slightly back. This provides higher hand positions and back angles for the rider, but still mounts to a stem with a negative rise, for better handling overall.

Because the steering axis of a bicycle is not vertical, stem angle changes how the steering feels. The shape of the connection changes how your weight controls the system. A stem that drops forward of the steering axis tends to center itself better than one in which the stem rises above 90 degrees to the steering axis. The steeper the rise, the more noticeable the effect. You can get used to anything, but once you know you can't overlook it. It's very annoying. That's why on so many of my bike builds after the advent of threadless headsets I left the steerer tubes long, piled up the spacers, and mounted stems with an angle of 90 degrees or less.

The bike industry reinvented the randonneur bar, as seen on some Specialized Roubaix models and elsewhere. The newer version has a wing top for more comfortable hand support, and rises more abruptly. They can do this because stems almost all have open clamps to allow for more weirdly-shaped handlebars that no longer have to thread the needle of an old-style single-bolt clamp.

You could really go on a Safari with this bike, or so the name implies.

Double eyelets on the fork would take fender stays and either a front rack or the more common handlebar bag with bungee cord stabilizers that hooked in down at the dropout.

The crank says American Flyer

The rear derailleur was bent. This was repairable in the Dark Ages of friction shifting:

Less repairable was the Suntour freewheel.

 I liked Suntour freewheels, but they had a tendency on occasion to disassemble themselves while you were riding, allowing the innumerable tiny ball bearings to fall out along many yards of highway. You could theoretically purchase replacement ball bearings and spend a meticulous hour putting the freewheel back together, provided that the pawls hadn't also escaped, but more often you would just buy a new freewheel and graunch down on the outer plate that held the whole apparatus together before trusting it. But the failure could be catastrophic. The worst case I saw was on a climb in Northern California, near Rockport. The rider's freewheel on his loaded touring bike came apart and cracked the flange of his nice Campagnolo Record hub. He and his riding companion had to camp on the side of the road for the night and hitchhike back to the nearest bike shop the next day, to get a wheel and freewheel so that they could resume their northward journey.

Time traveling forward to the present, the 21st Century is represented by this tubeless road wheel:

Tubeless tires for bikes barely make the slightest bit of sense for mountain bikers who could be riding on serrated ledges and over a certain size of angular stones while running fashionably low pressures, but even there I hear them lament that they burped a tire on one of those hazards and ended up with a flat tire anyway, often harder to reinflate in the field than a stupid old inner tube would have been. Your magic juice can leak out, making a seal to the rim difficult or impossible to attain. This is why tubeless riders carry a tube with them.

Setting up a rim and tire for high road pressures really highlights the absurdity of applying the latest fad to every category of bicycling. Road pressures severely challenge the sealing technology that evolved at very low off-road pressures. The process makes gluing tubulars look almost casual.

Gluing tubulars is potentially very messy, but at least you can see what you're doing. Move deliberately and methodically and you will succeed. 

Mounting road tubeless puts you at the mercy of microscopic discrepancies that somehow manage to be immune to the properties of the drippy sealant you have to pour into the casing. The setup shown in the picture, on the first attempt, was okay up to about 60 psi. It would not hold anything above that, no matter how I waved the wheel around to distribute the sealant. It was leaking into the rim somewhere. 

The original stem looked cool, but the rubber seal area at the base of it was rectangular, meaning that it covered less rim along one dimension than the other. Also, the rim tape had not bonded well enough, even though that was hard to judge by looking. I replaced the stem and peeled the tape, deep-cleaned the rim with alcohol, and then baked the wheel in the convection oven we use to heat-treat skis for glide waxing, to dry it absolutely thoroughly. That seemed to do the trick. The tire settled in at 90-100 psi and held it to the end of that day. I declared victory and called the customer. He said someone would be in to pick it up for him. My work week ended, and I left for three days.

When I returned to the shop, the bike was still hanging there. I pinched the front tire. It had gone down to squeezably soft. I reinflated it and heard hissing into the rim. Resisting an urge to take a fire ax to the goddam thing, I tried tightening the lock nut at the base of the stem. The hissing worsened. I removed the groovy plastic shim included with the wheel and went straight for lock nut against rim. Before tightening that, I removed the lock nut and pushed the stem into the rim so I could inject sealant around it to coat the base of it. Then I tightened the stem, re-seated the beads, and inflated the tire. It eventually seemed to hold quietly. I had barely walked away from this when the customer's father came in to get the bike. I said nothing to him or to El Queso Grande, who was handling the transaction. The tire was rock hard and seemed ready to ride, but I guarantee it will be back within a day or two. I can decide then whether to go for the tire levers or the fire ax.

The tubeless department had been getting a little chaotic, so I found a bigger receptacle for our tubeless paraphernalia.

The three-speed that this rim tape came out of may have been much older than fifty years.

I could barely make out some inscriptions in Aramaic on these scroll fragments.

A smokeless moped with a flat tire provided official acknowledgment that ebikes are mopeds:

An old Cannondale showcases the destructive interaction of human sweat and aluminum:

When I attempted to coax a stuck ferrule out of the cable stop on the frame, the stop popped off instead, because the aluminum was so oxidized. The deterioration is eating into the frame itself.

The frame also has some nasty dents from chain suck. It is now destined to be recycled into beer cans. Cheers!

The parts shortage this season led us to farm old inner tubes when common sizes went out of stock and would vanish instantly from suppliers' shelves when they became available again.

On to the next thing: This visiting rider said that he was having a heck of a time getting his gears to stay adjusted. At first he focused our attention on the front derailleur, because it's one of those Shimano models where you have to follow a six-page PDF of instructions to hook up the cable and set the tension. Eventually, though, he also mentioned that the rear shifting was incorrigible, too. Shimano's higher end mechanical shifting systems seem designed primarily to make people want electronic shifters.

The bike wins the award for Worst Internal Cable Routing, but that's a highly competitive category. I don't expect this entry to hold the crown for long.

The bike had those crappy brown-coated cables that get abraded almost immediately. Cable fuzz causes drag, especially inside the standard undersized 4mm shift housing.

This bike did have a full cover over the bottom bracket cable guides, protecting against a major entry point for dirt and water in internally-routed cable systems. The hatch cover was full of carbon dust from the cables abrading the cable guides, and a thick dusting of cable fuzz that had worn off of the wires themselves. 

Step one is always to yank out the brown cables and get some 1.1mm stainless wires in there. Step two is often to replace the housing with 5mm if the frame will allow. But when I was trying to thread the new cables I discovered that he had a bigger problem than cable fuzz and skinny housing.

The problem turned out to be the cable stop on the top tube, where the shift wires enter the frame for their dark journey through the mysterious interior.

That little doohickey inside the tube is supposed to be on top of the tube. It managed to fall inside, but would not come back out the same way. I had to remove the fork, which fortunately gave me access to the inside of the top tube. 

If you own a bike like this, expect to fork out a lot for repairs.
Someone had wrapped Teflon tape around the cable stop to try to wedge it into the hole in the top tube, but that merely reduced the width of the flange that is supposed to keep the stop from dropping in. I peeled the tape away, and reduced the size of the opening from the back edge, where the stop has a longer flange, to enhance the overlap of the narrower flange across the front. It was a bit of a hack job, but much of what we do is meatball surgery for riders who not only need a bike repair, but have limited time. This is bike service in a resort town.

We do have our year-round residents. I believe the doting Dad who wanted us to change the grip-style shifter on his daughter's 24-inch mountain bike to a trigger-style shifter endures the winters with us and doesn't just cherry-pick the summers.

The close-reach kid levers on the brakes don't leave a lot of room for the index-finger lever of the shifter pod.

Finger trap made in China.

Fortunately, kid fingers are small enough to work in the space available, and the pivot of the brake lever keeps it from pinching down on the upshifting finger. A larger lever, shut down to accommodate the daughter's diminutive digits, would end up just as close.

Two department store bikes came in at separate times for separate things and I noticed these helpful stickers on the fork:

We have frequently seen cheaper bikes with the forks mounted backwards, either by the owner or by a disinterested grunt at a big box store who was numbing his way through the assemblies for a management and clientele that don't know the difference. This sticker may help to reduce the frequency of that error.

After a brief hiatus immediately after Labor Day, repairs have picked up again, though not to the flooding volume of spring and summer. And many of the problems continue to be weird and time consuming on top of the lottery odds of finding parts that you need.


Rob in VA said...

Very entertaining article!
Haven't seen one of those American Flyer cranks before. Wonder if it's a JIS square taper spindle, or something odd.
Good explanation about the effect of stem angle on steering stability and feel - few people even realize there's a relationship.
Too many times I've seen cheap (mostly big box store) bikes on the resale market with fork installed backwards - that "rear" sticker was good for a chuckle.

mike w. said...

Your bikeshop horror tales make me glad i got out of the business when i did- pre-aluminum, clipless & index shifting!

Morlamweb said...

The scope of bikes that make their way into your shop never ceases to amaze me.

Your difficulties with the tubeless tire make me glad that I never took the jump into tubeless tech. Tubes have their problems, but their well-known and it's easy to fix a flat at home or on the road with simple tools and materials. So simple, in fact, that many people on tubeless wheels carry a spare tube or 2 anyways for flats in the middle of a ride!

Orang Basikal said...

Tubeless tires, disk brakes and suspension are among the borrowings from automotive technology which I have no desire to have on any of my pedal-driven vehicles. I had a disk parking brake and rear suspension on my Trice. the disk brake was endlessly finicky, and the suspension added nothing but weight.

I run tubes in the 72-spoke wire wheels on my Morgan (car). I wouldn't attempt to seal that many holes.

A bit of newer technology has come with some of my machines, but nothing I can't regress to an earlier kind when it wears out.

I hadn't thought about stem angle and height and steering when I replaced the original bars on my old Raleigh with a Nitto Noodle (for width) on a Nitto Technomic stem (for height). Yet I had always liked randonneur bars and had wanted to use them on past bikes, but never did. Perhaps my Raleigh would handle better with them. It's a bit wobbly these days, or is that me?

I've also seen backwards forks on d-store bikes, and occasionally on Craigslist.

cafiend said...

Stem height has less effect than stem angle.The Technomic is the way to get height without having a positive rise to the stem. But overall bar height can make a performance frame feel wobbly because it's designed to be ridden with the rider more wrapped around it than seated on it. Steep angles and short horizontal dimensions make the bike more stable when driving power down into it, as in a sprint. When you try to sit up and relax more, rider weight no longer provides the stabilizing force that a racing-style bike inherently lacks. Your grip on the bars is further above the center of rotation, thus destabilizing rather than enhancing stability.

cafiend said...

@Rob in VA: the American Flyer cranks looked like relabeled Suginos. The BB looked like square-taper, nutted spindle JIS.