Mature? Not Yet: Disc Brakes On Bicycles

In the mid-1970s, my high school acquired its first computer.  The father of one of my classmates, who worked in a nearby military base, in one of those jobs he couldn’t talk about, negotiated the purchase.  For $6000, my alma mater got a used machine, about half the size of a classroom—and with about half of the capacity of devices kids carry in their backpacks nowadays.

When I graduated the following year, one of my relatives gave me a new Texas Instruments Model 101 digital wristwatch.  With its red LED display and sleek goldtone band, it seemed like the epitome of elegance and slick high-tech, all rolled up into one.  No one else I knew had such a timepiece:  For the one and only time in my high-school years, I was the coolest kid in the class.  At least, that’s how I felt.

Neither the computer nor my watch made it past my sophomore year of college.  The big box (“It’s just an oversized, overpriced file cabinet!” one parent exclaimed upon learning what it cost) assigned classes like “Sports Heroes” to honors students who signed up for the Shakespeare seminar.  (I know.  I was one of those students.) And that was the least of the computer’s malfunctions. Worst of all, nobody seemed to know how to fix them.

And nobody seemed to know how to fix my watch.  One shop claimed that displays of numbers that had nothing to do with the time of day were a result of “water damage” –only moments after I took that watch out of its box.  (I have since learned that technicians and reps say “water damage” when your electronic device is acting up or not working and  they can’t figure out why.)

Less than a decade after I graduated high school, the Yankees were giving away digital watches (with the team’s logo, of course) as promotional items on Fan Appreciation Day. My graduation gift, in contrast, sold for more (in non-inflation adjusted dollars) than most smartphones or laptops cost today.  And the watches the Yankees gave away were more reliable (water resistant to 100 meters, and shock resistant) than the one I got on Graduation Day.   

I was thinking about the computer and watch as I read an article in the most recent Bicycle Quarterly.

In “Are Disc Brakes Mature Technology? “, Jan Heine recounts his and other BQ editors’ experiences with both mechanical and hydraulic disc brakes on road, mountain and city bikes.  While the brakes on one bike offered the power and modulation of good caliper brakes, their performance was hampered by their incompatibility with the levers that came on the bike.  The brakes on the other bike were not as good as road calipers and, worse, there were a couple of potentially serious failures. 

Heine seems to think that disc brakes have potential, but there are issues that need to be worked out.  Braking power is still determined mainly by the size of the disc.  A larger disc is heavier and could necessitate larger forks—both of which are anathema to racers and other performance-oriented cyclists.  More important, though, is that while larger discs offer more power, they seem to offer less modulation.  From what Heine and others say, it seems that larger rotors give the brakes the “all or nothing” feel that V-brakes (at least the ones I’ve used) always seem to have.

Avid BB7 disc brake on Look X85 cyclo-cross bike

The flip-side is, of course, that smaller rotors offer less power.  And, if there isn’t enough power, whatever modulation the brakes offer is all but irrelevant.

Another problem, as Heine points out, is that on disc brakes, the pad grabs the disc on the rear.  On a front fork, that means the wheel is pulled away from the dropout (or fork end).  When you’re barreling down a hill—or sluicing through traffic—few things are more dangerous than a front wheel popping out of a fork. 

Most modern quick release levers, Heine says, aren’t secure enough for bikes with powerful disc brakes.   Through-axles, like the ones found on downhill bikes, might be a solution.  But even with them, the fork blades on most non-suspension (telescoping) forks wouldn’t be stiff enough to counter the forces the brakes would put on them.  So, Heine says, a dedicated suspension fork might be the best kind to use with disc brakes.

 (In contrast, rim brakes pull the wheel slightly upward, into the dropout.  And their forces are concentrated in or near the stiffest and strongest part of the fork:  the crown.  That is the reason why properly-installed wheels don’t fall out of forks equipped with rim brakes or no brakes.)

I myself don’t plan to start using disc brakes any time soon:  I have never had trouble getting the braking power and modulation I need from rim brakes, as long as I use good cables and pads and keep everything properly adjusted.  Plus, there is something to be said for the simplicity, not to mention the lighter weight, of such brakes.  So, I hope that disc brakes don’t become the only option on new bikes or that component manufacturers stop making rim brakes and parts.

On the other hand, I am not against some bikes coming with disc brakes, or for such brakes to be offered on bikes where they might make sense.  Most of all, I hope they don’t become a de facto standard—or the only option—before they are a “mature” technology.  At least, when my digital watch failed, I still had the mechanical watch another relative gave me for a birthday—my 12^th or 13^th, if I remember correctly.  And plenty of others were available. 

Joaquin Is Going That Way...

Everybody’s been storm-watching for the past 24 hours or so.  They all remember Sandy and, from what the weather reports say, Joaquin is even more powerful.  But the wind and rain that’ve battered us today aren’t his fault:  A Nor’easter has worked its way along this part of the coast.

Joaquin, as of today...we hope!

Sandy became a “superstorm” when  merged with a Nor’easter before making landfall near Atlantic City, New Jersey.  It doesn’t seem that Joaquin will do anything like that:  He seems content remaining out to sea, well to the east of Montauk Point.  Still, he could gift our Nor’easter with even more wind and water than it might have whipped against, and dropped on, us:  As meteorologists tell us, the course of a hurricane is one of the most difficult things to predict.

There seems to be an interesting divide in how much concern people who lived through Sandy’s ravages are expressing about the prospect of another Nor’easter, hurricane or—superstorm?! From what my own admittedly unscientific observations, the folks on the South Shores of Staten Island and Brooklyn, and in the Rockaways, are bracing themselves.  Whether or not they’re making actual preparations, they are taking the reports and warnings seriously—more seriously, some admit, than they did when Sandy approached. 

On the other hand, residents of Long Beach and other communities on the South Shore of Nassau County—which, arguably, incurred even more damage than Brooklyn and at least as much as the Rockaways—seem more blasé.  As one man said, “I lost everything then.  I’m not worried now.”  But people in other devastated areas also “lost everything”.  In fact, in the Breezy Point area of the Rockaway Peninsula, houses that weren’t blown apart or washed away burned to the ground when water wreaked havoc with the electrical wires.  I recall seeing people who were able to retrieve only family photo albums before fleeing, or upon returning.

As for me:  I am watching the storms.  Aside from not having classes for a week, I wasn’t affected much by Sandy.  I want to make sure I can say the same thing about Joaquin or the Nor’easter.

Then again…Joaquin couldn’t possibly affect us as much as Sandy did.  After all, Joaquin is a male name, while both males and females are named Sandy.  Hell hath no fury like that of both genders, combined!

Vera Goes Gran Fondo

You tell yourself, "This is it!"

You're not going to buy another bike, you tell yourself.  The bikes you have are "for life".

No more changes, no more upgrades, you say.  You're not going to buy another part unless you absolutely have to replace something that's worn out or broken.  You won't buy another bike accessory, no matter how great it looks or whether you really wonder how you've lived without it. And you absolutely swear not to go to any more swap meets, spend any more time hanging out in bike shops or while away your evenings looking at bikes and parts on eBay.

And you promise yourself you won't lift another allen key or screwdriver, or squeeze your oil can or grease gun, unless you're doing maintenance that absolutely must be done to keep your bike rolling.

But you know, deep down, you're lying to yourself: Once you learn how to tinker with your bikes, you won't stop--no matter how little mechanical aptitude you thought you had before you picked up that first repair manual, that first edition of Anybody's Bike Book.

You always find something to fix, even if it doesn't need fixing.  And there's always some experiment you want to try.

So it is with Vera.  Just before I went to Paris, I had an idea:   I'd turn  her gearing from a typical "compact" road setup (well, with slightly lower gears) to something I'd never before tried:  Gran Fondo gearing.

Turns out, I had everything I needed for the experiment. Well, almost.  The crankset that originally came with Vera--a Shimano Deore triple from the late '80's or early '90's--was sitting in a box, just begging to be reunited with her.  A BBG 46 tooth chainguard/bashguard, also sitting in that same box, would look good on that crank--and on Vera--I thought.   And I had a nice Stronglight 46 tooth chainring I'd been using with my the compact double as well a Shimano UN-52 bottom bracket that, according to the folks at Harris Cyclery and Velo Orange, would work. All I'd need is a 30T chainring with a 74mm bolt circle, which I found easily enough.

I installed the chainguard in place of the outer chainring.  The Stronglight ring, made to be an outer ring for a double or triple, went on the middle position.  And, of course, the 30T ring was bolted on the inside.  

I installed the Stronglight chainring with the logos facing out, as if it were in the outer position.  That meant the chainring fixing nuts wouldn't sit flush with the surface of the ring, as the holes for the chainring bolts are countersunk on the opposite side of the ring.  That didn't seem to matter.  I've ridden the setup about 200 kilometers and it doesn't seem to be coming loose--and the nuts standing proud of the chainring surface doesn't seem to affect the shifting.

In this image, you can see the countersinking of the holes for the chainring fixing nuts.  You can also see a segment of an example of drillium at its best or most extreme, depending on your point of view!

Speaking of which:  I've shifted, well, only to see how it shifts.  I haven't ridden on the 30T ring.  But part of my intention in setting up the gears as I did--and, by the way, I set up the gears on Arielle, my Mercian Audax and Helene, my other Miss Mercian--was to spend most of my riding time on the larger ring and to use the smaller one as a "bail out" gear.

In any event, the shifting was even smoother than I expected it to be.  The Shimano 105 front derailleur from the 8-speed group is made to handle, as most modern road front derailleurs are, a 14-tooth difference between the chainrings.  Part of the reason why I haven't had problems with shifting is, I believe, that I'm using a non-indexed downtube shifter.  I wonder how (or whether) the setup would work if I were using Ergo or STI levers, or even bar-end shifters.

The bottom bracket's axle is 127 mm long.  The crank is actually made for the old-style asymmetrical axle:  The original bottom bracket is what's known as "121+5":  In other words, 5 mm are added to the right side of a 121mm axle.  Using the modern bottom bracket doesn't seem to affect shifting or my pedal position"  It just leaves more axle showing on the left side than what you see with modern cranks and bottom brackets.  However, if I keep this setup, I might splurge (if finances permit) for a Phil Wood bottom bracket with the asymmetrical axle.

In reality, riding with this setup isn't different from riding with the compact double, as I am using the 46T ring nearly all of the time.  But I think that it will allow me a greater range of gears, should I ever want or need them.

Vera seems to like it.  Truth be told, I think she likes getting the nice old crankset back.