Bike data analysis talk

July 20th, 2014  |  Tags: , ,  |  Leave a comment

I gave a talk at Spark Summit earlier this month about my work using Apache Spark to analyze my bike power meter data, and the conference videos are now online. You can watch my talk here:

If you’re interested in seeing one of these analyses in action, I’ve also made a short video demo:

Making sense of bicycling data

April 2nd, 2014  |  Tags: , , ,  |  Leave a comment

2014 04 02 at 8 46 AM

I’ve been working with Apache Spark a lot lately and recently wrote some code to analyze and visualize bicycling telemetry data with Spark. I’ve posted a more detailed writeup (including an explanation of what the above picture means) over at my work blog.

Should have seen that one coming

November 15th, 2013  |  Tags: ,  |  1 Comment

It was a little icy west of Madison today.

Regarding TdF doping

July 26th, 2013  |  Tags: ,  |  Leave a comment

As much as I love riding bikes, I generally assume that the very top of pro cycling is approximately as authentic and fair as the very top of pro wrestling. I didn’t watch the Tour de France this year and pretty much only followed the action and attendant controversies both legitimate (like l’affaire King) and manufactured (like the endless speculation about Chris Froome’s power files) on Twitter. But I was nevertheless interested to read this report from Cycling Tips’ “Secret Pro:”

In terms of this being a clean Tour, one thing I can say is that the style of racing has changed, even in the past five years. The previous generation of riders, who we all now know were dopers, would put in five or six attacks and then ride to the top of the HC mountain without even being out of breath. Now, you’ll only see a couple attacks and that’s it. Riders are coming past the finish line cross-eyed and completely destroyed now.

It’s important to keep this in mind when comparing this Tour to the ’90s and early 2000s. It’s much different to be riding a climb at threshold with only a couple attacks or responses in your legs versus what Armstrong and Pantani did. If you’ve ever ridden a bike and looked at your power meter to see what those types of efforts take out of your legs versus riding at constant threshold, you’ll know what I’m talking about. This is likely why some of the top climbers are setting times up the climbs that rival some of the fastest.

From my perspective as a mediocre cyclist who often becomes acutely aware of the pronounced effects of burning too many matches too soon, this makes a lot of sense. That’s not to say that the peloton is actually riding clean — we are, after all, talking about a sport where mad-scientist snake-oil blood treatments are deemed “not doping” merely because they are probably ineffective — but this explanation is a parsimonious response to some of the most prominent conspiracy theories.

Father’s Day gifts

June 21st, 2013  |  Tags: ,  |  Leave a comment

Didn't get hurt, didn't DNF, didn't DFL

Last Sunday I entered a mountain bike race (my first), and Andrea took the three kids out to see the end of my race and most of their Uncle Ben’s race, which was after mine. It was very hot1 and the kids were surprisingly cooperative, although they probably spent more time looking at tiny screens and snacking than watching people zoom by on fat tires.

Shortly after I finished racing and found the kids, I asked Thomas to go help me wash off my bike. He groused a little at having to abandon his tiny screen, but perked up a little bit when he realized he’d get to spray a high-pressure hose around in public. As we walked back to my car to return the bike, he had a suggestion:

“Hey, Dad, I think you should get a folder to keep all of your bib numbers in, and then you can also write down how you did in each race next to each number.”

At this point, I should clarify something about my bicycle racing habit. I am able to enter a few races a year. I really enjoy racing bicycles, but I am not particularly good at it. By “not particularly good,” I mean that I have identified a bug in USA Cycling’s iPhone app whereby if you were ranked, say 11th out of 11 in a given discipline and demographic, the site would tell you you were “first.” Although I’ve never formally reported the bug, my rankings could provide them with a large corpus of test cases: in multiple cycling disciplines and when grouped by zip code, state, racing age, or age range. My goals for a given race invariably have more to do with not getting dropped, lapped, or hurt than they do with a competitive or even above-average finish.

So I was charmed that WT wanted me to track my mediocrity over time, but such a record seemed like a good idea for him (he is an amazing bike handler and has been pretty successful at kids’ triathlons), and I told him so:

“That’s a great idea, but maybe we should start keeping track of your bibs and your results!”

“And Dad? When you get a rainbow jersey, you can put it in the folder, too.”

I smiled. “Thanks, buddy. But really, I almost certainly won’t ever get a rainbow jersey.”

WT thought about it for a few seconds. “Well, Dad, here’s what you’ll do. At the end of the race, you might be in fourth or something, and you’ll just have to go as fast as you can to beat the person who’s winning. See?”

Of course, I’m usually right around fourth from last rather than fourth overall, but it doesn’t matter. What more could one want for Father’s Day than a wife who loves you enough to drag your kids across the county to watch your ridiculous hobby on a sweltering Wisconsin afternoon, three children who love you enough to cheer when they finally see you, and an oldest son who thinks highly enough of you that he assumes you might be awfully close to best in the world at anything?

1 Thanks to some Dropouts for taking pity on Andrea and the kids and letting them evade the sun in their tent!

Cycling signs of the apocalypse

May 17th, 2013  |  Tags:  |  Leave a comment

“You got your decadent wastefulness in my boring hybrid bicycle!”
“No, you got this hilarious ‘urban’ cycle in my conspicuous consumption!”

Two great tastes that taste great together?

In any case, Gucci and Bianchi have done a great public service to cyclists everywhere by introducing this 22-pound, carbon, $15K “urban bike.” Every time a new bike purchase idea is met with spousal suspicion, no matter how ridiculous the proposal is (e.g., “I’d like an aero fat bike for drafting behind snowmobiles” or “I’d like to get a real track bike just so I can drive for two hours to the nearest velodrome and race”), one can simply point to this hilarious specimen as the ultimate real-world strawman. After seeing this, I don’t think I’ll even be able to chuckle at people who ride halo bikes on the commuter path. (And should you find yourself with $15k to spend on an all-purpose urban bike, please buy eleven Raleigh Ropers and donate ten of them to an appropriate local charity.)

Spring classics, Wisconsin style

April 17th, 2013  |  Tags:  |  Leave a comment

I often joke that Cross Plains, WI could host a Spring classic if they would just build a velodrome at the end of Church Street, but I suppose potholes and cobblestones aren’t exactly interchangeable. The weather in Madison is gradually moderating and — while it’s still too wet for mountain biking — we’ve had about a month of great totally adequate road riding weather now. Here’s a time-compressed video of a quick ride out to Cross Plains from last weekend; watch for the cobbled-classics infrastructure aesthetic from around 3:40–3:55:

Cross Plains 4/13 from William Benton on Vimeo. Soundtrack: “thieving magpie” by madcap ontic.

Black boxes for bicyclists

July 20th, 2012  |  Tags: ,  |  Leave a comment

This NYT article poses an interesting solution to an ugly problem: if helmet cameras become ubiquitous, cyclists will be able to document the actions of malicious or negligent motorists — perhaps even to the point where our characteristically bike-indifferent (or bike-hostile) criminal justice system will be forced to take victims seriously. But I fear that point remains distant. Consider one of the example cyclists profiled in the article, who

[…] wears a camera on his helmet during his 50-minute commute each way between his home and office. He began riding with the device this year after buying a $7,000 velomobile, a three-wheeled recumbent cycle with a shell around it.

Let’s imagine a pretty clear-cut case: the victim’s attorney (or a prosecutor) presents impeccable footage of a driver hitting a cyclist because he was distracted while putting puppies and kittens in a blender; goose-stepping towards the victim while screaming offensive epithets; and, finally, driving away without providing insurance or contact information. The victim’s case would be doomed immediately upon cross-examination. Can you imagine an American jury finding in favor of someone once they learned that he captured the incident from a helmet camera while riding a $7,000 tricycle?

  • Here’s a must-read article for pretty much anyone who uses roads: How to Not Kill a Cyclist. One tip it includes is to be patient and measured in your efforts to pass cyclists while driving, lest you “wind up in that worst of all worlds: a quantum state of simultaneously passing and not passing.” (Link via Podiumwear on Facebook.)


Logistics regressions

May 23rd, 2012  |  Tags: , , ,  |  Leave a comment

We were rear-ended at a stop light a couple of weeks ago. Thankfully, no one was hurt and our car appears to have escaped major damage, but our hitch-mounted bike rack was totaled in the impact. The other driver’s insurance company offered to reimburse us for the cost of a new rack as advertised on Since Amazon’s price was nontrivially cheaper than what we’d paid for the original rack at a local bike shop last year, we ordered the replacement instead of purchasing it locally.

When the new rack arrived, it had two shipping labels on it: the first was for shipment from Amazon’s warehouse in Plainfield, IN to my house in Madison, WI. The second indicated that it had previously shipped from Saris headquarters (where it was assembled) to Amazon’s warehouse in Plainfield, IN, perhaps on-demand. Readers based in Madison probably see where this is going, since they know that Saris headquarters is less than three miles from my house; in fact, we share a ZIP code.

It’s hard to imagine a better example of the perils of hub-based routing.

Dear St. Olaf College

April 13th, 2012  |  Tags: ,  |  2 Comments

Dear St. Olaf College,

Although I may never totally let you off the hook for selling WCAL, ignoring the myriad helpful suggestions I offered you in the enthusiasm of youth, and raising tuition and fees by over 250% in the last 12 years, I still love you — after all, you introduced me to my wife and many of my lifelong friends, you more than adequately prepared me for additional higher education, and you taught me to like Haydn, among other things.

As you surely recall, one of my favorite pieces of apparel is this sweatshirt:


I’ve had it since I was 16 (i.e., for more than half of my life!), and although it is faded, too large, and frayed at nearly every seam, I intend to keep it until it completely disintegrates, because there hasn’t been a St. Olaf sweatshirt since that’s worth the great memories I associate with the Hill. I thought I’d lost it once. In the frenzied post-graduation move-out exodus, a friend accidentally liberated it from my coatrack peg in the Huggenvik House, believing it was hers and she’d left it behind while hanging out. I was despondent until it showed up, neatly wrapped, as a surprise wedding gift over a year later. (Well played, Wilsons!)

Although I continue to hold out hope otherwise, I’m beginning to doubt that you will ever make a piece of St. Olaf-licensed apparel that is nearly as great as this classic sweatshirt. What I’m realizing now is that you may not have to. You see, this afternoon, I received a small parcel from one of the officers of the St. Olaf Cycling Club. It contained the items pictured below, either of which is almost certain to steal affection from my venerable sweatshirt:

Jersey and cap

I’m pretty sure that wearing a cycling cap off the bike, even for demonstration purposes, is a Rule #22 violation, but it runs afoul of Benton’s Second Sartorial Law in any case. So mea culpa BUT GOOD GRIEF IT SAYS “UM YA YA” ON THE BRIM. Fortunately, I should still have some long-sleeve weather left this spring in which to wear this excellent kit, and I expect to find myself thinking “Fram, fram!” instead of “sur la plaque!” while so doing.

Seriously, though, you should fix the sweatshirt situation, because the cycling club is just embarrassing the bookstore here. I’m pretty sure that the climbing wall, the fancy science center, the sommelier service in Rand, the heated and asbestos-free practice rooms, the chairlift on Old Main Hill, and whatever other decadent amenities you’ve installed since I graduated wind up tasting like ashes in the mouths of students who can’t enjoy them in worthy licensed apparel.

Will Benton ’00

Simpler cue sheets

March 31st, 2012  |  Tags: ,  |  Leave a comment

I can’t possibly be the first person to have had this idea. With that said, I like it a lot:

cue sheet on phone lock screen

As for the ride itself, it was overcast and certainly too cold to refrain from second-guessing wardrobe choices. (Bibs and knee warmers: bad idea. Shorts without knee warmers: worse idea.) Even so, we were doing pretty well until we hit Mt. Horeb and a thick fog rolled in. Just a couple of miles north of town, we were blind beyond about 100m, which seemed like unnecessarily bad odds for us given the size of the shoulders and the speed of traffic.

So we went back to town under rapidly-increasing fog cover and surveyed our options for a few minutes. We considered going to the Grumpy Troll and trying to wait for some sun, but it was before 9 AM and neither of us had any cash. We considered calling Andrea and begging for a ride, but that seemed too pitiful. Anyway, if you were wondering whether it is possible to ride the Military Ridge State Trail from Mt. Horeb to Madison on road bikes with 20 spoke rims and 700×23 tires, the answer is “yes, but only slowly.” (For out-of-towners, this is about 20 miles on crushed limestone and dirt.) I probably wouldn’t do it by choice, but it’s always fun to ride that trail and I don’t think my wheels are too far out of true. And — as an unexpected bonus — I’m pretty sure I can speak Flemish now.

Inappropriate commuting gear

February 28th, 2012  |  Tags: ,  |  Leave a comment

Dear Amazon, you know I’m your pal. I still have that handwritten thank-you card you sent me on my fridge, although my motivation for keeping it is at least 60% ironic. So when you do something like this, it hurts me all the more:

Why are clip-on aero bars and bicycle commuting even in the same paragraph?

As someone who has been nearly maimed by clueless aero bar users in multiple mass-start road cycling events and who has had pleasant commutes sullied by weirdos who (1) are using aero bars on a bike path and while so doing (2) insist on attempting to draft someone who is riding a steel fixed-gear bicycle at sub-competitive speeds, I must plead with you to never again mention bicycle commuting and clip-on aero bars in such a way that someone might construe them as being somehow related to one another or (worse still) part of a desirable combination for shaving 15 seconds off of their Cap City Loop time. Thanks in advance.

(See also: the most appropriate inappropriate web ad ever.)

  • I liked this reflection on training and racing from pro bicycle racer Neil Bezdek, and especially appreciated this sentence: “I train a lot because it’s fun, and racing professionally gives me an excuse to do so.”


Visualizing last summer’s road cycling

January 3rd, 2012  |  Tags: ,  |  Leave a comment

I recently plotted some of my local road bike rides from last season using TileMill, the TIGER map data from the US Census Bureau, and exported activity routes from RunKeeper. I had a pretty good sense of what ride I do the most often (a fairly flat 18-20 mile out-and-back that I can complete in under an hour unless car traffic is awful — great for time-constrained rides and intervals), but I was interested to see where else I’ve gone. The results turned out pretty well, so I’m posting them here. I only plotted road rides in Dane County, only rides on a geared bike (i.e., no commutes), and I chose only a subset of all my rides. The paths are lighter or darker proportionally to how frequently I traveled them.

Arboretum detail

The figure above is a close-up of the section of the map including the UW Arboretum and the Capital City Trail. This was by far my most common ride in 2010, but I did it much less frequently in 2011. (In fact, I think I rode this route more frequently on my fixed-gear than on my road bike in 2011.)

B11 paoli

This is a detail of some of my favorite short hill-climbing loops near Paoli, WI. The loop to the lower left is more challenging (and more rewarding) but I didn’t do it as often. To the upper left is the beginning of a fast and fun route to Mt. Horeb, WI that also serves as the beginning of the WI Ironman cycling loop. I’m hoping both of these will be substantially darker at the end of next summer!

Biking sm

Finally, here’s the whole map, cropped to include Madison (for context) and the parts of western Dane County that I actually rode in.

I did these manually, so the obvious next step is to write up a little program to generate these automatically. I’d also like to have a more interesting visualization (like making paths thicker instead of darker or perhaps incorporating elevation and average speed data somehow). Overall, though, I’m pleased with these results. I was quite impressed with how easy TileMill was to use, and am optimistic that this toolchain, combined with some additional cleverness and care, could produce a really compelling presentation of these data.

Stop pedaling, start driving

October 12th, 2011  |  Tags:  |  Leave a comment

I saw this link from Swobo’s Twitter feed. GM briefly ran an ad earlier today in which they encouraged college students to “stop pedaling [and] start driving” by participating in some discount program that would presumably make it easier for them to buy a new car:

Ad, via
(Image credit:

I find this concept and its execution ill-advised and gauche but am unable to muster righteous outrage about an ad campaign that makes fun of cyclists; surely, a car company needs to portray their product as preferable to alternate modes of transportation, or else they’d be making bikes (or city buses, sedan chairs, spaceships, tuk-tuks, etc.). But I did chuckle over the following two points:

  1. Apparently, we’re encouraging college students to take out new-car loans now. I guess most students will have paid for the car before they’ve finished paying for their liberal arts degrees (the Chevrolet Sonic featured in the ad is roughly equivalent to a semester at a private college circa 2011), and you can occasionally resell a car for some fraction of what you paid for it, while your BA in music history1 or whatever is less likely to provide any tangible return. Still, it seems callous to prey on people who, by virtue of their status as customers of higher education, have such an obvious predisposition for making bad financial decisions.
  2. I own three bicycles. Each was made by a different company with different characteristics: small companies and large companies, companies that source other manufacturers’ components and companies that design their own components. However, they all have something in common: none of these manufacturers has needed a massive infusion of government cash to stay in business at any point.

At least GM has something in common with their audience here: both have decided that they deserve freedom from the consequences of bad choices, even if they can’t quite explain why.

1 I say this with particular authority, since I graduated college approximately three credit-hours short of a BA in music history.

Motivating technology

March 1st, 2011  |  Tags: , ,  |  Leave a comment

Like many computer scientists of a certain age, I spent a nontrivial part of my graduate career going to academic talks about “sensor networks,” which were apparently an extremely hot research area in the early-middle aughts, suitable for distinguished lectures early on, faculty candidate talks later, and targeted research areas for not-particularly-prestigious academic job postings long after the rest of the field had moved on. The basic idea was that you’d have these enormous collections of tiny, autonomous primitive computers that were capable of self-organizing and reporting interesting-in-the-aggregate results to somewhat more powerful computers.

Sensor networks work touched on a lot of interesting challenges in systems and engineering, and the talks were always fascinating from a bottom-up perspective. But it always struck me as a solution in search of a problem. The motivation for these talks, perhaps due to the political and funding climates of the time, was always wrapped up in vague ties to national security. Depending on the host institution of the researcher presenting, the always-implausible hypothetical applications for this technology might involve placing one sensor in every cubic meter of the San Francisco Bay in order to detect bioterror attacks, or perhaps placing one sensor anywhere in the Charles River in order to verify that you should not place yourself in the Charles River.

If only these talks had led off by introducing ANT+, I would have maintained my interest far more readily. ANT+ is a real-world sensor network technology with a useful application (collecting data from fitness equipment like heart rate monitors and bike computers) that has to meet nontrivial engineering challenges (for example, working when everyone in a race is using them simultaneously). As a practical bonus, having a single standard for these devices means that I can track my bike computer or heart-rate monitor from a watch or from a cell-phone dongle — and that I can add additional data sources easily without being locked in to a single manufacturer.

Every computer scientist I know has given at least one talk with some ridiculous big-picture claim as the ostensible motivation, even though everyone in the room knows that — to use an example from one of my own talks — program analysis is interesting to computer scientists, on some level, whether or not making good software is uniquely hard or expensive among engineering disciplines. Not every research focus lends itself to a motivation that is both likely to occur in the real world and compelling to nonspecialists. But I’m inclined to believe that the field would be well-served by devoting more effort to finding such motivations, and the problems that they imply.

Two almost comically depressing links

November 8th, 2010  |  Tags: ,  |  4 Comments

Roadside assistance

It looks like Eagle, CO might be as bad a place to ride a bike as it is to be a 19-year-old female hotel employee. Apparently, Vail Valley District Attorney Mark Hurlbert is willing to avoid pursuing felony hit-and-run charges against an investment banker who ran over a cyclist and only stopped to phone Mercedes roadside assistance in order to report the damage to his car. His rationale is that a felony conviction would negatively impact the perpetrator’s career.

One might assume that Hurlbert is merely weary of the increasing criminalization of the American public, and that he allowed this (admittedly completely egregious) offense to slide with misdemeanor charges in order to make some ideological statement about the nature of punishment. One would be wrong, though, as Hurlbert has also pursued felony criminal-impersonation charges against two women who exchanged race numbers for a mountain-bike event.

There’s not a lot I can say about this story without using naughty words. However, I would like to apologize to the town of Middleton, WI, for anything negative I have ever said regarding its climate for cyclists. I’ll take antipathy and incompetence over corruption and abject hostility any day.

Cargo cult security

Bruce Schneier points out that the future of in-flight wi-fi is in doubt as a result of the attempted cargo plane bombings on UPS flights from Yemen; while these package bombs did not have internet-enabled triggers, such a trigger exists in the realm of logical possibility, so it’s obviously better to outlaw in-flight internet access altogether.

Schneier notes that this will not prevent any known class of attack (and, indeed, leaves less-sophisticated bomb triggers involving timers and altimeters completely unaffected). Personally, I assume that every passenger and bag will soon have to pass through an electromagnetic pulse, right after the security groping and peepshow.


    I tacked a 15-mile detour onto my 3.5-mile commute home in honor of yesterday’s dailyshoot assignment ("Make a photo that represents your mode of transportation today.") You can tell by looking at the chainrings that my mode of transportation is probably sad that I primarily use it on roads and paved trails.

    Click the photo for the flickr page with more sizes (I recommend the larger ones to see chain detail), metadata, and flash nerd info.


  • In honor of the Tour de France, I’m now linking to the only two times I’ve mentioned Lance Armstrong on this site: in 2004 and in 2009. (I’m rather fond of the latter.)