Austin Tri-Cyclist Blog

Monday, May 9, 2011

The 40k Time Trial
An Hour of Power, an Hour of Pain

The History

Time trialing began in the late 1800s in England as a response to a national ban on road racing. At the time, instead of conflicts being between cyclists and cars as they are today, it was often cyclists and people on horseback. After some accidents and subsequent complaints, cyclists in England were in danger of being banned from the roads completely, and racers were seen as a threat that could inspire legal action against all cyclists. To prevent that eventuality, the National Cyclists' Union prohibited racing on the road, hoping to keep the races to the velodrome, just as car enthusiasts today encourage kids to keep the racing on the track. Few velodromes existed, however, so underground organizations formed and began a new racing format that they hoped would not attract so much attention.

The first time trial on public roads may have been in 1895, when Frederick Thomas Bidlake organized a 50-mile race against the clock. Drafting was not yet against the rules in these races, but riders were set out at 2- or 3-minute intervals, with the fastest going first, so drafting was unlikely to occur.

Over time these events evolved into races of 10, 25, 50, and 100 miles, with records being tracked for each one. That 25-mile distance, when converted to the metric 40 kilometers (24.85 miles), would become the 40k TT we know today.

The Significance

Perhaps by accident, or perhaps inevitably, the 40k TT comes up again and again as a relevant and important distance not just in cycling, but in triathlon as well.

  • State and National Championships - The 40k TT is often the standard distance used in regional and national time trial championships. Any cyclist interested in winning the yearly TT championships in his or her category will have to focus on this distance. In some regions the women do a shorter distance, but in Texas, women do the same course (because Texas is awesome).
  • The Gold Standard - The Hour - In days gone by, when the 40K was actually 25 miles, and when time trial bikes had round steel tubes and bullhorn bars and wheels had spokes, going under an hour for 40k was seen as a gold standard for cyclists. If you could do that, you were serious business. Since then, equipment has come a long way, and a sub-hour 40k won't even always win a cat 5 TT. However, for triathletes, who spend a large portion of their training time running and have to carry around an upper body that is actually useful so they can swim, breaking an hour is still a gold standard. Going sub-hour is proof of studly-ness (on the bike, at least), especially if done in the course of an Olympic distance triathlon (but only if you don't blow up on the run).
  • Functional Threshold Power (FTP) - FTP is defined as the amount of power a cyclist can average for one hour. This happens to be an interesting physiological power level, as it represents the crossover point between an almost entirely aerobic power output, and a power output that starts eating into anaerobic reserves that will eventually fatigue you. Cruise around at slightly less than your FTP and you can go for a long, long time. Cruise around slightly above it and you will soon blow up. Many coaches and athletes use this metric to set up training zones. There are many ways to estimate your FTP but the one way to get it exactly right? Go as hard as you can for an hour. For most people, a 40k TT and a power meter will be the best way to do that. To geek out further - Go Here.
  • Olympic-Distance Triathlon - One of the most popular distances in triathlon is the Olympic distance, when it first starts to get serious. The bike leg here is 40k, with a 1,500m swim before and a 10k run after. Age group athletes who can break an hour mid race have a good chance of starting the run in the lead. Also, while they rarely time trial it solo, ITU athletes making their bid for the Olympic games also bike this distance in their draft legal format.

Where to Race in Texas

  • Iron Haus Time Trial Series - First Saturday of each month - Great out and back course with a wide shoulder the whole way. Located just west of San Antonio in Castroville Texas. You only need to touch the brakes once at the turnaround. It's an informal event, so you can sign up online or the morning of.
  • Horse Country TT Series - May 14 and July 17 - Located in Aubrey, TX, this TT course features smooth roads, wide shoulders, and a bit of climbing.
  • CapTex Triathlon - May 30 - One of the biggest triathlons in Texas. The CapTex bike course is in downtown Austin. It is a twisty, crowded, multiple-loop course that will test your handling skills as well as your threshold power. Somehow this course remains fast despite the turns and crowds, perhaps due to the constant draft affect of passing slower waves.
  • Mineral Wells Summer TT - June 25 and 26 - Event still tentative, check the link for updates
  • Marble Falls Triathlon - July 17 - A wee bit short of 40k at 23 miles, but another beautiful bike course with no loops and no crowds. A big uphill to start things off and a fast downhill to finish it.
  • The Small Texan Triathlon - July 24 - Is 40k not quite enough? Runner studs got you down? This smaller event in Boerne, Texas, just outside of San Antonio, adds an extra 5k to the bike course for this otherwise Olympic-distance event. It will be hot, there will be no shade, but there will be a great course with beautiful water to swim in before you bike.
  • Texas State Time Trial Championships - July 30-31 - Details TBD but this event usually takes place somewhere in Central Texas near San Antonio. Anyone can sign up and they even include a multisport category for triathletes and duathletes. There is also a team competition the following day.
  • The Austin Triathlon - Sept 5th - Another huge event with tons of quality competition, The Austin Triathlon takes place in the same location as CapTex with slightly different courses. The 40k bike has the same challenges of twists and traffic, with multiple loops.
  • The Houston Triathlon - Sept 25 - A standard distance event near Houston.


A 40k Time Trial is an exercise in pain and patience. Athletes who go out too enthusiastically will explode enormously. The best way to pace it is an even effort with perhaps a little kick in the closing minutes. It takes great pain tolerance to keep that effort up all the way through. A bike computer can help you pace if the course is flat and winds are low. A power meter is even better; if you know your FTP you can just hold your average power right at it (easier said than done!). Click here for a sample power file of a perfectly paced, sub hour 40k. Stop by ATC and ask about power meter or bike computer options. Even better, stop by ATC any time and head upstairs to the trainer cave and make use of the ATC Computrainers for free! Just ask Don or Adam to help set you up.

Training for a 40k TT will be pretty familiar to triathletes who are used to constant, evenly paced efforts. Cyclists may want to take a break from short intervals and sprinting in the weeks leading up to a big event. One popular workout is to do 2x20minute intervals at threshold power.

Get aerodynamic! We covered most of the key tips here in our Victory by a Thousand Cuts in February. Be sure to clean that bike of clutter and remember you will need little, if any, water for a 40k TT.

Copyright (C) 2011 Jack Mott


  1. What? No comments about the attic training dungeon on the CTs? The chase for the highest one hour power!

    There's info missing here!!!!!!!!!!

  2. Good call MarkyV, I've added a bit about the upstairs trainer cave!