Gent Six Day Leg Extension

Its the first day after my knee op, and I am already bored, so I decided to download a 30 day trial of dartfish (www.dartfish.com). This is the software we use at cyclefit analyse a rider's biomechanics.

I used it to analyse the leg extension of some of the riders at the 2008 Gent Six Day's penultimate madison. It was interesting as racing a track bike on a 166 metre velodrome has so many differences to standard road riding that we usually see. Here is a list of some of the differences.

1. possibility of shorter cranks

2.more aggressive (shorter/ lower) position as using smaller frames and always on drops

3. narrower q-factor

4. g forces pushing when through the banking

5. Non- symmetrical riding

6. very little out the saddle effort

7. higher cadence

8. fixed gear

My estimates are only rough. I can't go down there and put tracking dots on their knees! But the theme of the results for leg extension were interesting.

-Bruno Risi 32.5°

-Leif Lampater 40°

-Schep 35°

-Andreas Beikrich° 45-50

-Keisse- 43°

-Zabel 37°

With the exception of Bruno Riso, Schep, and possibly Zabel, all the riders seem to have very low saddle heights. When I am fitting at Cyclefit I get an average of about 32/33°. The demands of the track are obviously a lot different. I feel there are several reasons.

1. It enables the riders to maintain a more stable pelvis for the much higher cadence's used

2. The lower handlebar position puts more strain on the hamstrings so reaching a larger extension is very difficult- especially repeated night after night

3. the fixed gear at high cadences puts less torque on the joints (just speculating)

4. It is more stable when doing a madison change

On the other hand, the wide range (32.5° to almost 45) shows that I might be completely over analysing their reasons for having a lower leg extension, but the mean of the extension's is 39 degrees. Personally, I think that around 35-37° (on average) is perfect for the Gent track if we look at the two extremes, Keisse and Risi. I am not convinced that Keisse is achieving his full power output, as we can see when he drops his heel during a sprint to achieve a larger angle. I think that Bruno Risi is slightly too high as his hips are rocking and he grips the handlebars quite tightly in comparison to the other riders to stabilize himself. Just some thoughts...