update on iBike test...

It's a real-world test, in that I actually bought one! So how's it going?

Well for around $US400 from iBike itself it's a bargain, so you'd allow for some rough edges. But so far it hasn't shown too many. Get it set up right (it's not hard to do) and allow for its obvious limitations (such as it relies on barometric measurements of air pressure coming in through that little slot in front, so anything that distorts airflow - like turning sharp corners, sudden dips or objects blocking the air intake - will also distort the power calculations. And of course it won't work on an indoor trainer... yet) and it's a powerful tool that gives accurate figures. I have back calculated and verified my iBike data against some basic, manual calculations and it falls within a few percent of what I'd expect, given speed, weight and inclination (that's hill slope, not my inclination).

It has given some doubtful results that appear as spikes in the data. I've seen 1495W once in a sprint - possible but I thought unlikely. I calculated it was closer to 750-800W, so manipulating the .CSV file eliminates that spike. I have since then sprinted at a maximum (and believable) 800-1000W many times with just one other sprint appearing doubtful at 1466W. I had already re-done the "coast" test because of the 1495W spike, and I'm confident that the coast-down is now correct. So either I really did put out 1466W for a second or there's something else going on. Strangely enough both spikes were in the same location... like exactly in the same spot. I'm thinking there's a dip in road or some other strange factor I'm missing here...

So out of over 500km of testing it's so far given me 2x 1-second spikes of doubtful data. The rest of the data looks good, with a steady improvement in wattage from an average of 168 over about 45 minutes to the current best of 210W for 60mins. When I remove the "zeroes" from the data it "normalises" to 230W over 1 hour (and 220W over 90minutes). Given that I'm not racing at the moment (which I imagine would lift those figures substantially) I'm satisfied that the iBike is working and also that training-by-power is effective - if only because it has re-motivated me!

More soon...