Thoughts on Time Trial Start Sheets

Anyone who has taken part in a time trial will know that the start sheet not only defines the event and when they start but will also have an impact on what their own performance and result. This blog looks at how a time trial start sheet is constructed, and how it also impacts rider safety.

A time trial start sheet must define the name, bib number and start time of each rider, and can contain additional information such as club, team, gender, age, and age category.

The order of riders in the start sheet is a key consideration. According to the CTT regulations, “the Event Organiser shall have discretion to arrange the starting order as they wish bearing in mind the characteristics of their event and the need to avoid company riding as far as possible.“

The CTT regulations explains company riding by stating “Competitors must ride entirely alone and unassisted and not ride in company or take shelter (commonly known as drafting) from other riders or vehicles. A competitor overtaking another must pass without receiving or giving shelter. The onus of avoiding company riding shall be upon the rider overtaken.”

Maximising rider safety must be the primary consideration in organising a time trial. Company riding in time trials is not only unfair, but also reduces rider safety by increasing the risk of collision with other riders or vehicles. Specifically:

  • Riding close together, one behind the other, gives an unfair advantage to the rider behind (drafting), and is unsafe because another rider or vehicle trying to pass has to take longer to do it
  • Riding close together, one alongside the other, (including overtaking), puts the rider on the outside in the unsafe position in middle of the carriageway where they are exposed to other vehicles

So, what is the best way to prevent company riding when defining the starting order?

I Googled “How is time trial order determined?” and got the answer below from Wikipedia:

“Starting times are at equal intervals, usually one or two minutes apart. The starting sequence is usually based on the finishing times in preceding races (or preceding stages in the case of a multi-stage race) with the highest ranked cyclist starting last. Starting later gives the racer the advantage of knowing what time they need to beat.”

The “order of speed” algorithm is easy to apply if the data on preceding races is known and is commonly used. It is the algorithm used by the CTT startsheet generator. However, it suffers from the following problems:

  • Faster riders catch up with slower riders, causing bunching near the finish, overwhelming the person trying to record the finish times as well as causing the company riding problems described above
  • Peers (riders with similar past performances) start at similar times, so differences in speed are low; when one rider does catch up with another overtaking can take a comparatively long time, exposing the overtaking rider to additional danger. Also, the overtaken rider is disadvantaged as they may have to slow down to allow the overtaking rider to get far enough ahead so no drafting takes place

The easiest way to avoid these problems is simply to increase the start time interval. The CTT regulations state one minute as the minimum for individual time trials (which can be reduced to 30 seconds with police permission or on closed circuits) but no maximum on open roads (30 minutes on closed circuits). One minute intervals are almost universal. Increasing the interval increases the overall duration of the event, with the associated problems too numerous to mention. Other solutions are needed.

The algorithm most commonly used to avoid the problems above is the “spaced order of speed” algorithm. This algorithm spaces peers typically 5 or 10 riders apart. A race of 50 riders with a spacing of 5 is used to explain how it works:

  •          Allocate riders to one of 5 groups according to speed, fastest 20% is group 1, next fastest 20% is group 2 etc
  •          Group 1 is loaded into the start sheet, fastest rider 50, next fastest is 45, etc
  •          Group 5 is loaded into the start sheet, fastest rider 49, next fastest 44 etc
  •          Group 2 is loaded into the start sheet, fastest rider 48, next fastest 43 etc
  •          Group 4 is loaded into the start sheet, fastest rider 47, next fastest 42 etc
  •          Group 3 is loaded into the start sheet, fastest rider 46, next fastest 41 etc

With this algorithm, a rider catching up with a slower rider will be more likely to be significantly faster and spend less time overtaking. There will be fewer opportunities for drafting. They are also less likely to catch up with a peer.

Increasing spacing reduces the problems, but the amount you can increase it depends upon the number of riders in the event. For example, a suitable spacing for 10 riders would be 2; for 50 a spacing of 5 is appropriate, for a 100 or more, 10. Giving the fastest riders the magic last digit of 5 or 0 on their bib number makes them instantly recognisable.

The “space order algorithm” has been automated in the TT event tool. When the number of riders is not an integral multiple of the spacing there will inevitably be gaps in the start sheet. These gaps can be used for riders entering on the day of the event.

The spaced order algorithm does not obviously deal with the problem of bunching near the finish. One solution is to start riders in reverse order of speed, fastest first. This principle is applied in road races where the fastest riders go off first so they are not blocked by slower riders. This principle can be easily applied to both the order of speed and spaced order of speed algorithms. It ensures that the fastest riders will not be obstructed near the finish. However, there are the disadvantages. One is that it increases the overall duration of the event and may reduce excitement as the winner will be known long before the last rider finishes. This is fine for road races but not so for time trials. Second, if younger or less experienced riders encounter problems then they are not likely to get help from other riders if they start last. There are no broom wagons in time trials.

Organisers often have to deal with special requests such as an early or late start. Also, reserve riders may need to be added, or riders may be able to enter on the day. One way to deal with these requirements is to include anonymous riders from each “speed” group in the start sheet. On the day entrants, reserve riders, or riders who want to be moved on the start sheet, can be assigned these anonymous rider positions.

So, when you see your next start sheet, study how it has been constructed. It might tell you a lot about the calibre of riders you are competing with!

Jon Fairclough 12th May 2023





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