On 6/13/2019 4:06 AM, Rolf Mantel wrote:
Am 13.06.2019 um 01:21 schrieb John B.:
As an aside, 250 watts is probably as high, or perhaps higher, than
the usual recreational cyclist normally produces.

My health insurance says 2 watts per kilogram body mass is a healthy,
above average value.Â* So a normal recreational cyclist is likely to have
a sustained output on the order of 100W (typical female, 50kg) to 150W
(typical male, 75kg).

In 2003 I had a stress test and according to my notes, I hit 250 Watts
max. That worked out to 2.95 W/kg.

On one hand, that was at my limit. OTOH, that was on a treadmill. I
suspect that I'd have been able to do a bit better if I were on a bike.

On the third hand, I doubt I could come near that value these days. Age
makes a difference.

Tying back to the original discussion: So the efficiency tests we're
discussing were done at high power. Chain drives are more efficient at
high power levels. But I suspect the same is true for gear drives. I
don't know that a lower power test would change the relative efficiency
rankings.


--
- Frank Krygowski