April 28, 2023
In the Meantime
On My Mind
Things I've been thinking about as the tour nears.
Where the Wind Comes Sweepin' Down the Plain
Oklahoma is windy almost all the time. And spring is the windiest time of year, particularly March and April. Windy days aren't as notable as days without wind. And I've had to get ready for this tour at just this time of year. My rides the second half of March averaged wind gusts of 29 mph. The two windiest days gusted to 45 mph. I managed not to ride the day it was gusting to 56.
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I just keep telling myself that I'm prepping for the ride west through the Columbia River Gorge come July, a place so consistently windy in the summer (from the west) that it's one of the most popular kiteboarding locations in the United States.
Because I'm a nerd I actually gathered daily (and hourly) summer weather data for Hood River, Oregon in the gorge for the period 2017-2021 to analyze it. Suffice it to say that the average wind at Hood River in the month of July over those five years was 20 mph gusting to 32 mph from the west-northwest. The windiest July day was 27 mph gusting to 47 mph. I did discover that the wind lays down somewhat at night, so if we get up at or before the crack of dawn we should be able to get in a few hours of riding before the wind really kicks in.
Can't wait. Stay tuned.
Life on the Middle Chainring
I spend the vast majority of my time on the Plow Horse riding the middle chainring. Except to make sure the shifting is working, I've never found the need to use the large chainring. I do use the small chainring to climb steeper hills, but in 5,000 miles on the Horse I have combined it with the largest cog on the cassette only twice.
The first time was climbing a hill south of Petosky, Michigan that we nicknamed "The Wall". That's what it looked like as we approached it. I stopped looking at the grade on my GPS when it reached 12% to take time to cough up a lung. Not sure how steep it got.
The second time was climbing the gravel road up to the campsites at Devil's River Campground near Maribel, Wisconsin. The office was in the river valley. The campground was on the bluff. I had to get off the bike to walk part of the way to the top. I don't think it was even 10% grade, but I was tired after a long windy day, and my rear tire started slipping on the loose gravel. I was concerned that I didn't have the rope I'd need to rappel back to the bottom in the morning.
Keeping that last, lowest gear forever in reserve if possible soothes my psyche. Shifting into it knowing there's nowhere else to go.....not so much. I'm guessing the hardest climbing tests won't wait until we get to the Rocky Mountains.
How High Is High? How Steep is Steep?
Is there a bicycle computer out there with a GPS altimeter? I don't know of one. The bike computers I've owned (Garmin and Wahoo) have had barometric altimeters. Barometric altimeters have issues.
If the weather changes while you're out on a ride, a front comes through, you're sucked into a tornado, the altimeter interprets the change in barometric pressure as a change in elevation. You don't end up with an accurate record of climbing and descending. You circle back to the beginning of the ride and find yourself at a different elevation than when you set out. Mountain building? Erosion?
In a gusty wind, a barometric altimeter interprets the transitory pressure changes as changes in elevation. Ride the length of a perfectly level dam in a gusty wind and the altimeter shows that you're going up and down hills. The amount of climbing and descending is greatly exaggerated.
The Wahoo doesn’t seem to accumulate feet climbed if the grade is less than, say, 0.5%-0.7%. At those low grades I can watch the elevation change without those feet being counted. Yes, maybe it doesn’t feel like climbing, but it should count.
And don’t get me started about how the Wahoo will report one climbing number, but when the ride gets loaded to Ride With GPS a different climbing figure appears. Or how if you plan a route with Ride With GPS, then ride it, the climbing figure comes nowhere near the figure predicted. I wish the bike computer folks and the route planning/saving folks would get their acts together or at least be transparent about their algorithms.
One Thing I Won't Miss and One Thing I Will
I had to go to the Apple Store in Penn Square Mall here last week to buy a new case for my phone. Such an indoor desert. Not that I mind shopping, as long as I know what I'm looking for. When I lived in Norway 40 years ago I loved going shopping in downtown Stavanger to the gågata (walking streets). Shops lining narrow pedestrian-only vehicle-free streets. So what if it was cold and raining and the wind was blowing. May they never roof it over and control the climate. The thought of shopping at a mall makes me shudder. I hope not to see one the whole way. If I don't I won't miss it.
Years ago my wife planted a couple of tiny prickly pear cacti in our flower beds. The one in the back yard has languished. The one in front by the street has become a monster. My wife has asked me to cut it back, but I've refused. It's practically a national monument. People out for their walks often stop to marvel and photograph it when its abloom. I expect tour busses some day. Just don't accidentally brush against it. This spring it's going crazy with new pads and flower buds. The flower display in a few weeks will be awesome. One year I processed the juice out of the ripe prickly pears and made prickly pear syrup and prickly pear ice cubes to go into my watermelon lemonade. Yum! I'll miss seeing it once it blooms.
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Doing lots of riding in areas with a small but accumulating hills, I've also been curious about accurately measuring height gain. This is tricky and calculation based on topology (DEM) measurement that the main planning sites use can be inconsistent - in some cases *really* consistent (i.e. wrong) if they have missing data, e.g. above certain latitudes as I found out in Norway! https://www.cycleblaze.com/journals/middlesweden/technical-note-incorrect-elevations-at-high-latitudes/. I resorted to running a smoothing algorithm on the GPX data - this nearly always decreased my elevation deltas and so climbing amounts.
At least some Garmin devices do what you suggest and combine both GPS elevation and barometric altitude. The idea is - and I've found this bears out in practice - GPS gives accurate absolute numbers, while barometric gives precise changes in elevation. The GPS device is used to periodically automatically calibrate the barometer.
Relying on GPS alone also leads to jagged elevation profiles (e.g. when a signal becomes weak) and so tends to somewhat overestimate climbing. The barometer alone as you say can certainly "wander" as pressure naturally changes with the weather - in practice I've found this drift to be of the order of maybe 10-20m *but* your mileage may vary: it could be that in my maritime, Atlantic location we aren't exposed to such dramatic pressure changes as in Tornado Alley! For at least some devices (I'm using a Fenix 6 watch) there seems to be sufficient shielding from air currents that I've not seen them affect the barometer: Cornwall is also a very windy and gusty location and it doesn't seem to affect my GPX tracks (and if incoming breeze would perturb the barometer I'd expect to see a systematic effect with air flowing past when riding at different speeds). The barometer is very sensitive (it can actually detect a 1m altitude change for me standing up!) so I'd suspect this would show up if it was a problem.
This combination I've found to be very reliable when repeating the same routes, under very different conditions. It does indeed give rather different results to planning with a digital elevation map - RideWithGPS always underestimates climb by at least 10%! I don't know if this is coarseness in the DEM data, or that my "real world" cycling behavour weaves around in a way that isn't captured by those site's routing.
Apologies for the long note - you just tickled my geek instincts!
1 year ago