Can Trainer Road and the CycleOps Fluid 2 Trainer Produce Consistent Results?...

Test-1 @ 80 rpm

Test-1 @ 85 rpm (dropping 2 cogs)

Test-2 @ 80 rpm

So one of the biggest questions about Trainer Road (and other similar programs) that produce a virtual power is "Are the numbers accurate?" or "Can they produce repeatable results?"

My somewhat non-scientific testing done today and seen in the charts to the left would seem to indicate that the results are repeatable enough to allow use of the program as a reliable training tool.

Are the numbers the same as you would get using a $1000 to $1500 power meter?  Probably not.  But they do match up pretty well to the numbers I got last year riding on the CompuTrainer, a system which sells for $1600 plus and that doesn't include all the software necessary to graph results and create workouts.  My testing was done by warming up the trainer for 5 minutes.  Then spinning for a minute at as consistent a cadence as humanly possible.

Test-2 @ 85 rpm (dropping 2 cogs)

One minute tests were done at 80 rpm and then dropping 2 cogs and spinning for one minute at 85 rpm.  Then the bike was removed completely  from the trainer, a bit of air was let out of the rear tire and the resistance unit backed off from it's clutch locked tire tension position.

The tire was then aired up again to 100 psi, the bike placed in the trainer and locked into the same position.  The resistance unit was then tightened until the clutch mechanism slipped one notch indicating proper tension on the tire.  The second set of tests was then run.

As you can see from the charts, the results are very similar, accurate to a watt or two at the same cadence.  That's close enough that I think it safe to say you can use Trainer Road and similar programs as a useful (if not completely accurate) training tool.  And given the cost it's a bargain for the cyclist that would like to train with power on occasion but who isn't ready to take the $1500 plunge into crank or pedal based power metering.

As I spend more time using the program I will post updates, so stay tuned :-)

(For those interested: Testing was done using a Mavic Ksyrium Equipe wheel with a CycleOps Trainer tire inflated to 100psi, CycleOps Fluid 2 trainer with slip clutch tension adjustment and Garmin GSC-10 speed/cadence sensor.  The test file was then exported from Trainer Road and imported to Strava for "analysis").