My unit arrived earlier this week. I set it up and calibrated yesterday. It looks good compared to what I was seeing in Gen I, with the power surges on rough roads eliminated as John said they would be.
I reckon my GEN i was generally oversating my watts for rides, as a comparison I rode a few hills at my normal intensity and I was about the same as Geni at 340 - 360 watts over 5 minutes. But it is on the flat I am seeing lower wattage than on Gen I.
Do these calibration figures from my coastdowns and out and back look ok to you Gen III experts?
Aero 0.248
Windscale 0.782
CdA 0.316
Fric 5.893
Riding tilt -0.1%
CRR 0.00612
GEN III calibration
Re: GEN III calibration
How tall are you and how much do you weigh? Also, what is your normal riding position? If the watts sem ok on the climb but not on the flat it tells me that your cda might need to be increased slightly.
When you are going down a hill at speed and you backpedal, do you see any watts? Then try doing the same thing in a slightly more aero position. If you have a good calibration you should see right at zero watts in your normal position and 10-15 watts in an aero position backpedaling at 25mph.
This isn't the law though, the numbers can vary for everybody, but this is one way I check my numbers without having to use a DFPM as comparison.
When you are going down a hill at speed and you backpedal, do you see any watts? Then try doing the same thing in a slightly more aero position. If you have a good calibration you should see right at zero watts in your normal position and 10-15 watts in an aero position backpedaling at 25mph.
This isn't the law though, the numbers can vary for everybody, but this is one way I check my numbers without having to use a DFPM as comparison.
Boyd Johnson
http://www.boydcycling.com - high performance carbon wheels and accessories
http://www.boydcycling.com - high performance carbon wheels and accessories
Re: GEN III calibration
Boyd,
I am not doubting the Watts on the flat on the Gen III really, I am more thinking GENI when I got over 20mph on rough roads was giving me high numbers on the flat e.g. 300 watts when RPE was much less than pushing 340 on hills.
I am 5'9 and a half, weigh 159lbs. Normal ride position is on the hoods.
I used the interval marker yesterday, and did one hard effort on the flat at 275, got a hard 5 min hill at 340,
I had a bit of a taily coming home and was noticing that putting out 22mph on the flat I was only 150 to 180 ish watts.
RPE for the whole ride I'd have guessed it was 240w on GEN1, but my GenIII download for the whole ride was 186 with a wko normalised of about 245 I think.
I reckon I will have to re-establish my FTP entry on WKO as GENi I was doing 300FTP, I reckon I might be nearer to 280 on GenI with the more stable recording at higher speeds. I think the fact that it returns 0 immediatley with the cadence sensor (I was speed only on GenI) when freewheeling brings the average for the whole ride down more.
I' am going to do a flat out 50 mins course which I did last week on Gen I tonight and see how the outputs differ!
I am not doubting the Watts on the flat on the Gen III really, I am more thinking GENI when I got over 20mph on rough roads was giving me high numbers on the flat e.g. 300 watts when RPE was much less than pushing 340 on hills.
I am 5'9 and a half, weigh 159lbs. Normal ride position is on the hoods.
I used the interval marker yesterday, and did one hard effort on the flat at 275, got a hard 5 min hill at 340,
I had a bit of a taily coming home and was noticing that putting out 22mph on the flat I was only 150 to 180 ish watts.
RPE for the whole ride I'd have guessed it was 240w on GEN1, but my GenIII download for the whole ride was 186 with a wko normalised of about 245 I think.
I reckon I will have to re-establish my FTP entry on WKO as GENi I was doing 300FTP, I reckon I might be nearer to 280 on GenI with the more stable recording at higher speeds. I think the fact that it returns 0 immediatley with the cadence sensor (I was speed only on GenI) when freewheeling brings the average for the whole ride down more.
I' am going to do a flat out 50 mins course which I did last week on Gen I tonight and see how the outputs differ!
Re: GEN III calibration
Your numbers look like they are in the ballpark. You can always try doing the cal again. You can do as many of them as you like and see how they compare.