the bike & the track - ~112 miles @ ~23.5 mph


I did a bike ride!

See the strava activity here.
See some future challenges here.

This article is focuses on biking data & training targets and is meant to serve as:

  • a personal reference for calibrating future race targets & fitness challenges
  • a reference for helping others calibrate future race targets & fitness challenges based on their relative fitness metrics

This makes me care about things like how my bike sounds, my FTP, GPS accuracy, wind speed, whether or not I cleaned my drive train and other things most people don’t care about. Thoughts here are generally scattered – I’d like to write more structured articles about training, performance & prediction soon.

I did a bike ride!

in circles!

the challenge

On May 2nd 2020, I was scheduled to race an Ironman in St George, Utah near Zion National Park. I was excited for the trip – I had been looking forward to spending time with my family & girlfriend and my training had been coming along.

The race & the trip were unfortunately cancelled due to the COVID-19 outbreak. However, I wanted to put in a good race-like effort on the day the race would have happened.

I decided to do a “shelter in place” Ironman bike leg and ride 112 miles at the ~0.7 mile cycle track in Golden Gate Park in San Francisco.

OB, SF - i rode here a few days before

why do a bunch of laps?

  • could be fun
  • staying local good for not spreading COVID-19
  • wanted to see how fast I could go in “ideal” conditions
  • seemed like a good challenge for mental focus
  • read the book “Endure” and was excited to do cool feats of strength & focus
  • wanted to prove I am nuts
  • this is a good stepping stone for bolder challenges to come
  • no traffic lights, stop signs, etc.
  • could help gauge kona qualification prospects
  • could help me pace future ironman races
  • could help calibrate race-pace speed, heart rate, power
  • opportunity for good data analaysis from segment splits, heart rate, cadence, power, etc
  • could get a lot of strava kudos (13 now, a new record)
  • could make a new “Golden Gate Park Ironman” segment on strava and become KOM



I trained a bunch for the Ironman – maybe I’ll write about it in another post & share training resources. My goal was to qualify for the Ironman world championship in Kona via a top ~1-3 age group finish for M25-29 at the North American Championship in St. George.

I’m probably not there yet, but am getting close.

stat value
FTP a month ago 348 W
estimated FTP now 360 W
body weight ~165 lbs
FTP W / kg 4.67 - 4.8
70% of FTP (ironman pace) 243 - 252 W

My biking FTP was 348 W about a month before this time trial. I paced the FTP test convervatively though – my 5 minute splits were ~350 W, ~360 W, ~380 W, ~390 W. I’d guess I could hold 380 W for 20 minutes which would make an FTP of 360 W. Maybe I couldn’t though. My FTP is definitely above 350 W and maybe closer to 360 W.

I weighed 165 lbs = ~75 kg for the FTP test and the time trial. An FTP of 350 - 360 puts me at a W / kg of 4.6 - 4.8. This is getting me close to Kona Q territory. But extrapolating a 20 minute test to an Ironman is noisy. I might also want to race at 160 lbs but 165 lbs is good for the trial.

Online calculators suggested I could hold 230 W - 250 W for an Ironman and that I should be good for about 23 mph or maybe a little less. I figured 23 mph was a nice round number, so I made that my “A” goal. 23 mph is 4 hrs 52 mins, which is close to 5 hours, so 5 hours was my “B” goal. 10 minutes seemed like a good buffer, so 5:10 was my “C” goal.

To make a strong Kona bid, I probably want to hit at least 23 mph / 4:40 - 4:50 on a road course with hills and such. So this would be a good test!

level goal mph goal time
A 23.0 mph 4 hr 52 min
B 22.4 mph 5 hr
C 21.6 mph 5 hr 10 min


I did the trial on a ~2007 cervelo P3 with deep race wheels. I wore a tri suit & aero helmet. I stayed on the aero bars the entire ride, except when quickly getting gels or blocks or gatorade from my pocket or bike. I didn’t carry a flat kit since I was just doing laps. I carried 3 gatorade bottles - 1 on the frame and 2 on the saddle. I had 3 gels in my pocket and 2 packs of blocks. I also carried my phone for music.

I tuned and fully cleaned my bike in the week leading up to the trial. I cleaned the casette, chain, and drive train. I reset the derailers and breaks. Re-tapped a stripped dropout screw hole in the frame for setting the rear wheel position. Unstuck a stuck seat post. Re-taped some of the handle bars. I lowered my front bars one extra notch and raised my seat a bit for aero. This bike has come together slowly in parts from craigslist & ebay and I am very happy with it after a lot of work.

The bike cleaning alone may have given me 0.5 - 1.0 mph. And the aero gear maybe another 0.5 - 1.0 mph. Hard to say, especially since I would later discover the power data from this ride was garbage.

getting the bike ready

the ride

bike distance (GPS) 112.79 miles
bike time 4 hrs 48 min 16 seconds
bike speed 23.5 mph

run distance 3.12 miles = 5k
run time 21:08
run pace 6:46 / mile

I did it! Probably! I hit 4:46 for the Ironman and averaged 23.5 mph according to my GPS data. The strava effort is a little longer since i did an extra lap in case there was some later rounding error. GPS might not be that accurate and I might be a few minutes slower. But close-ish.

I measured the ride with a Garmin Forerunner 935. It may have been more accurate to count laps instead of relying on GPS. I was mostly riding on the inside lane of the track, though sometimes on the outside lane.

I might be off by ~1 mile (~2 min 38 s) due to the accuracy of GPS while doing tight circles. My time for the 100 mile GGP strava segment suggests I might be closer to 23.2 mph which extrapolates to 4:49:40 for 112 miles. But the last 12 miles were below the average for the ride, so maybe slower overall. Lap-by-lap Strava analysis shows I might be closer to 22.9 mph.

I also did a 5k run after the bike ride at 6:46 min / mile (2:58 marathon pace). That was hard! I want to run sub 3 (or close to it) for the Ironman marathon, which I realize now will be a huge challenge considering how hard that pace was for a 5k. My marathon PR is 2:39 (6:06 pace), though I got hurt earlier this year and haven’t been running high mileage – I’m probably in ~2:50 shape now.

my general thoughts were:

  • yay! this was actually great. I had a blast and would do it again once I think I can hit a strong new PR
  • really nice to not have to stop at all. i rode this straight thru the 4 hr 48 mins and only touched the breaks once for another cyclist
  • Need to get stronger for the Kona Q – want to hit this effort on real course and run a solid marathon after. Maybe a nice day with no rain and mist, a functional power meter, fixing noises on the bike, adequate fueling, conservative pacing, and a race environment will help? Doesn’t hurt to just get stronger.
  • I did a lot of talking to myself like “85! YOU GOT THIS! TOO EASY! SEND IT HOME!”. this was probably was obnoxious for other folks at the park but that’s ok. i listened to mostly country music the whole ride, though my headphone batteries died after 4 hours. i’ve thought about crossing my Garmin data with my spotify logger data, maybe one day.
  • I went out hard … i hit ~2:15 for the half ironman and was averaging 24.5 mph for a lot of the early 5 mile splits. at mile 30, i could feel i was working too hard. It was cool to beat my santa cruz half ironman time by 20 minutes in the first half. This trial was flat and I rode a TT bike in aero position vs. rolling hills & road bike at santa cruz, but I’m also stronger.
  • I’m glad a went out hard rather than conservatively so that 1) I had a shot to greatly exceed my goal (e.g. hitting 4:30) and 2) I was forced to push through the fatigue for miles 70 - 112 & build toughness. “Endure” discussed this type of hard early pacing, so I just thought about the book during the ride and how I should enjoy any pain
  • My heart rate was generally 130 - 140 during the ride, later creeping up to 140 - 150. Usually I cannot ride 23 mph @ 135 bpm but today I could which was cool. My heart rate hit 31 the night before which was low. Usually is like 33 - 37 bpm while sleeping.
  • It might have gotten windy? Hard to know if it was fatigue or wind. Power meter is useless. Power meter says I am 66% left foot at 175 W. I definitely have reasonably equal pedal laterality and am closer to 220-260 W based on physics of moving 165 lbs + 22 lbs @ 23 mph. Power meter cut out a bunch of times has been generally broken. I have gotten 2 parts kits from the the manufacturer to fix defects, but it is still bad.
  • Next time, might want to figure out counting laps vs. using GPS and how to approach that
  • On the Tuesday before, I squatted & deadlifted, ran 5 miles @ 5:48 / mile, & biked 25 miles. My legs were still sore Saturday, especially since I haven’t really been lifting. But glad i just went for it and sucked it up and pedaled depite the fatigue
  • Road was wet and air was misty for the first ~2.5 hours, but made for a really nice temperature, not getting thristy, etc. My bike started creaking and sounding terrible thought after ~2.5 hours, maybe from wet weather?
  • The monotony actually wasn’t that big of a deal compared to just the total level of exertion. Aggressive early pacing caused more strain than doing hundreds of that same lap
  • I didn’t eat enough and didn’t bring enough snacks for the ride. I had 3 gels, 2 packs of blocks, and 1 bottle of gatorade which probably wasn’t enough. I had 2 more gatorades available but didn’t want to use the bathroom.
  • I crossed paths with a coyote right outside my door in SF as I was leaving at 5:30 am. And made friends with a cat while getting ready at the track. We saw turtles the evening before. Those were cool!

lucky turtles the evening before