Speeeeed

How much gain is there in speed/effort when riding in a group as opposed to on your own? That is the question I have been asking myself this week, a quick trawl through the inter-web wasn’t very informative. Why is this important? My primary objective when completing L’Etape is avoiding the Broom Wagon; the minibus that rides behind the pack during the race and picks up riders going too slowly. The speed the Broom Wagon drives at is published just prior to the event and this year during a mountainous L’Etape it was set at 17.5Km/h. So if I assume that next year the Broom Wagon will be set at a similar speed then I need to work out my target minimum speed. There are several unknowns for me here: How does 17.5Km/h over the profile of the stage compare to a typical ride around Hampshire and how much speed will I gain by riding in a pack? A colleague of mine rides on the track regularly and is confident that track cyclists gain between 6-8Km/h when riding in a line vs. riding on their own. I quick check on the Beijing Olympic Track Cycling results shows that the team pursuit winners rode their 4Km at 61.7Km/h whereas the individual winner rode his 4Km at 56Km/h that equates to a gain of around 10% which is not bad at all. I would assume that Track Cyclist get a better draft gain than road cyclists as they are much closer to the wheel in front so maybe a road cyclist could gain 7.5%? It is not very scientific but good enough for me.

If I now look at Mountain stages vs. Flat stages that may give an indication of what speed I should be riding on my training rides. If I take a couple of stages on this year’s Tour de France to compare:

Flat Stage 13: Nimes, 182Km won by Cavendish in @ 40.5Kmh
Mountain Stage 17: Alpe D’huez, 210Km won by Sastre @ 34Kmh

That equates to a loss in speed of around 20% on a mountain stage vs. a flat stage; much lower than I would have expected to be honest.

We could combine these to estimate the net gain/loss which means you would expect to ride approximately 12.5% slower on L’Etape compared to riding on your own around the Home Counties, so to beat 17.5Km/h on L’etape then I need to be targeting around 20Kmh. A much slower speed than I am currently training at. I feel great today!

I wonder how accurate that is...