Originally Posted by
chaadster
What I was getting at is why is this true? Are you talking power meter equipped spin bikes, or ones that estimate? If meter equipped, how do you account for the optimism in their readings?
I ask because, as I'd said, I thought all meters used the same type of gauges for readings, and so while the numbers may be different one to another, I would expect them to be consistent (important for training programs) and not wildly different.
For example, do you think we can expect, say, a Cascade CMX Pro Power to yield similar numbers to a Cycleops 100 Pro (assuming both are calibrated to same standard)?
I wonder if part of the issue is that it's very hard to know if an indoor cycle actually uses a power meter, or if it's estimating? Some of these makers are quite explicit about the type of meter, e.g. Spinner's SpinPower, but others are vague, like the Cascade; I mean they say it "measures power," but really only detail a "wired power console," the mixed terminology causing uncertainty in my mind.
I use a Cycleops 420 Pro, best cycling investment I have ever made. It's not a "spinning" bike, it is an indoor training bike, but you can spin your guts out, or low cadence climb your guts out, whatever makes you happy. It uses the same PowerTap as in a Powertap wheel. The advantage is you can measure in a conditioned room, replicating exactly the same conditions for each test, which makes it very accurate to measure progression.
On my road bike, the Powertap wheel seems to measure a bit higher, perhaps 10%, but it is a difficult comparison, as there are hills, wind, turns and one is not comparing apples to apples. But if I do a 5 minute interval on a flat road has hard as I can and I compare it to the same interval, same average cadence on the Cycleops, my road power is around 10% higher.
About the original posters question, regarding spinning:
Personally, I peaked in June, racing and training 12 to 17 hours per week on the road and stopped the racing season early. Then followed weight work in the gym and 3 x 45 minute spinning sessions per week, doing 2 minute intervals around 115 rpm cadence and 310 watts. After 9 weeks, my power is up about 30 watts and I have only lost about 25% of my long distance endurance. So, for me, spinning really works well. For those who are high cadence challenged, it is a real bonus!
PS. A Cycleops 100 is just a indoor training bike, no power measurement. The 420 Pro has power and electronic resistance modulation, either to pre-programmed watts, or to gradients on a Google Earth road ride, or an actual recorded ride on Virtual Training.