Our Lord and Master Strava

Hydrangea just beginning to blossom

I get questions about inconsistencies in Strava data, probably because I’m not only the gear maven but also the most versed in trigonometry in my circle of riding friends. And some of the biggest inconsistencies involve elevation data.

Elevation data is rubbish. The base data is rubbish: unless an elevation has been confirmed by human surveyors, you can’t trust it. And then elevation as determined by GPS — is rubbish. Your GPS device can determine your location with signals from just two or three satellites, but for elevation to be meaningful it needs a minimum of four satellites. And it’s still wildly inaccurate.

PR and KOM

After my morning commute, I had a couple of very surprising results which drove home the above points.

montage of Strava profiles of overlapping segments
Our Lord and Master Strava

When I arrived at the office (and convinced Garmie to sync) I was stunned to find a KOM and a PR for essentially the same segment — the first climb of the day, a gradual rise along the western edge of Chuo Koen (Central Park). The top shows my custom segment (which explains why I have a KOM — no competition) and the bottom a public segment.

Close inspection shows that my custom segment gives the elevation gain as 9m, for a 2.8% average, while the public segment at bottom has an elevation gain of 15m, for 4.7%.

Now here’s the point — and try to stay with me here — the custom segment at top wholly contains the public segment below. Yet the the elevation data shows a 66.7% greater climb in the wholly contained segment.

As I was saying: rubbish.

(And far from being KOM, in the public rankings I’m just barely in the top 50%. Where I belong. Depending on the segment, I tend to be in the top 10%-50% … )

Baling wire and chewing gum

GPS record of morning and evening bicycle commute
Just making ’em up as I go

In (perhaps) totally unrelated news, the weather has been very good so far this week — excellent commuting weather. I didn’t ride Monday and Tuesday as I was coming off a 135km weekend ride, but I couldn’t resist the good conditions today.

Apart from the PR on the first little rise this morning (which I totally didn’t expect — I just felt like I was cruising, neither fast nor slow), I had another amusing result after my ride home.

Strava refused to match my ride with any of the 4-5 segments that are usually included in this route. When I prompted Strava to match one — a short but steep climb at the start of my commute home — it showed me the overlap between the public segment and my “as ridden” data, and refused to accept they were overlapping.

All the above is not really the fault of the GPS unit I’m using. Similar results (and discrepancies) can be found with any of the major brands. We’re triangulating* from an altitude of 20,200km to a base of a handful of meters using a device that weighs a few hundred grams, fits in the hand and has a battery life of 20 hours. When you’ve got a singing pig, you don’t complain that it’s occasionally off-key.

* A lot of people far more intelligent (and possibly less drunk) than I am have put an awful lot of effort into making GPS work, and my hat’s off to them. And I freely and humbly offer my apologies for the horrible over-simplified hash I’ve made of how the damn thing really works.

And the living is easy

Hydrangea just beginning to blossom
Almost summer

Meanwhile, it’s almost summer. The weather looks good for a ride this weekend, and rainy season is on the horizon after that. I hope to get the riding in while it’s good. Following the 135km effort last weekend, I’ve surpassed 400km for the month for the first time since October 2021, and I’m on track to go more than 500km


Just now, Nana was watching over my shoulder as I watched Stage 1 of the Tour de France.

I have no idea why this is interesting.
Guy Jean:
That feeling that you’re feeling right now?
That’s what I feel when you’re watching baseball.

“The hardest climb in cycling”

Today is Stage 14 of the Giro d’Italia, and that means it’s Zancolan time: “10 km at an average 12% gradient, with peaks topping out at 22%,” according to the official site.

“It’s brutal. It’s relentless,” Mitchelton-Scott sports director Matt White told Cycling Weekly.

For me, it’s the hardest climb in cycling. Bola del Mundo in the Vuelta a España is hard, but this goes on for nine kilometres. It’s 40 minutes for the first riders, but for us mortals, it’s one hour. One hour of going all out.

Sky sports director Matteo Tosatto

Except where noted, all quotes are from Cycling Weekly. Tip o’ the hat to Joe Lejog for the link.

Band-Aid stocks are up

I let Joe know that we were woefully unprepared for road rash incidents. This advice did not come out of nowhere, incidentally …

road rash
Road rash

Some idiots apparently don’t know their limits, and attempt to bunny-hop curbs to avoid traffic. At speed. And it behooves us to be prepared for such idiocy in future. So I told Joe that I’d volunteer to bring the goods for the next ride (or at least the next ride I attempt).

Band-Aids and disinfectant
Band-Aids and disinfectant

I’m pretty sure none of this would have happened if I’d been carrying the omamori from Ai-chan.

Fujisan omamori
Fujisan omamori — thanks, Ai-chan!

Paean to the lowly onigiri

Onigiri, or rice balls, have got to be about the ultimate biking food. Compact, cheap and readily available with a variety of fillings, onigiri provide upwards of 170 calories in a prepared meal that you can eat one-handed in a couple of minutes.

Lunch on the road
Lunch on the road

A representative of MLB in Japan told me that when Matsui went to play with the Yankees, a chef was hired to make him nothing but … onigiri. Onigiri after practice, onigiri after the game.

I don’t know about you, but if I had a chef whose only responsibility was to make rice balls, I’d expect some pretty spectacular rice balls.

The first thing to note about rice balls is they’re … um … triangular.

Triangles of nutrition
Triangles of nutrition

One variety lets the white rice stick above the nori seaweed paper: a Fujisan rice ball.

Rice balls typically come wrapped in a special cellophane envelope which keeps the nori crisp until it’s time to eat. Unwrap by following the numbers: 1, 2, 3.

Mentaiko: spiced cod roe

Shake: salmon

It’s true that when I’ve been riding frequently, I can get onigirid out. But considering I burn a rice ball’s worth of calories per hour (or thereabouts) when riding, onigiri are hard to beat.

When I took up riding again more than six years ago after a hiatus of a couple of decades, I would ride five or six hours without eating anything. When I finished I’d eat like a pig, but it was obvious I was abusing myself. I’d get throbbing migraine headaches. Once I took up the habit of tanking up on the go, the problem went away.

And so now I wonder: what will we eat on the road from London to Paris?