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Saturday, September 19, 2015

PERT Estimate and Triangular Estimation for Gear Selection

Triangular Estimation or PERT Estimate is used for an approximate probability distribution or range estimate in Project Management. I suppose one can use the same technique to select gear ratios to ride on the track based on historical data of the rider, equipment and type of track being used.

The PERT Estimate formula is P + 4(R) + O divide by 6

P = Pessimistic
R = Realistic
O = Optimistic

The Triangular Estimate is P + R + 0 divide by 3

So for example based on historical data of the rider and the events, you can estimate what gear to use by using the PERT Estimate or Triangular Estimate:.

Flying 200 Meter at Kissena Velodrome

Pessimistic gear ratio = 90"
Realistic gear ratio = 96"
Optimistic gear ratio = 108"

Using PERT Estimate
Therefore: 90 + 4(96) + 108 divide by 6 = 97" gear ratio

Using Triangular Estimate
Therefore: 90 + 96 + 108 divide by 3 = 98" gear ratio

500 Meter at Kissena Velodrome

Pessimistic = 90"
Realistic = 92"
Optimistic = 96"

Using PERT Estimate
Therefore: 90 + 4(92) + 96 divide by 6 = 92.3"

Using Triangular Estimate
Therefore: 90 + 92 + 96 divide by 3 = 92.6"

Lets say you need to select one gear to take part in several events but you are too lazy to change the gears for each event, you can use the estimating technique to chose an appropriate gear for all events. Lets say the three events are SCRATCH, MISS & OUT and POINTS RACE.

MISS &  OUT = 88"

Using PERT Estimate
Therefore: 88 + 4(90) + 92 divide by 6 = 90"

Using Triangular Estimate
Therefore: 88 + 90 + 92 divide by 3 = 90"

I will be using these formulas more often since I have the historical information I need for gears which I have used for various events at Kissena Velodrome, it would definitely prevent me from reinventing the wheel and selecting wrong gears after a long lay off from racing on the track.

Of course other variables to take into consideration are:

Density Altitude
Track Conditions
Time of Season
Your level of fitness
Your optimum cadence range - mine is 110 rpm

Monday, September 7, 2015

9 7 2015 Kissena Track Labor Day Races

Most Photos taken by Avelino and Teressa Pereira - thanks guys.

Didn't have the fitness required for these longer track races. I finished fifth in the six lap 45 plus scratch race and couldn't finish any of the other races. Lack of endurance training with longer intervals and partial recovery is required for these types of events. Rode a 96 inch gear today - 50 x 14.....gearing was a little bit ambitious, should have rode a 92 inch.