Out of the blue big difference between DFPM and AeroPod power, not sure why that should have happened, any ideas please?
Getting some better data now. doing benchmark repeats for a few sessions now to get a view on repeatability.
Thanks Rob
What's happened here?
What's happened here?
- Attachments
-
- Screenshot (661).png (121.15 KiB) Viewed 5236 times
Re: What's happened here?
Here we go ....
- Attachments
-
- Velocomp_05_27_2020_1430_14_Miles.ibr
- (201.21 KiB) Downloaded 201 times
Re: What's happened here?
Shorter file from same venue, aborted because the SRM PC8 wasn't picking up speed.
- Attachments
-
- Velocomp_05_30_2020_1542_5_Miles.ibr
- (65.97 KiB) Downloaded 191 times
Re: What's happened here?
You've got 3 things going on:
1) In the 14 mile ride, you used the "Check Calibration" procedure to tweak your ride. That's OK, except...
The original, untweaked ride file shows that you bumped your unit at the 8 minute mark, causing slope to go very negative. Isaac does its best to fix this, but the bumped section (from minute 8 to 18) has really wacky slope and watts. In fact, it looks like, for most of the ride, your PP was not mounted in a stable position.
2) Your 14 mile ride also shows that wind is too high. The Check Calibration feature fixes this
3) It sounds like you have an SRM. These are super-tricky to calibrate, because of their ancient method of slope-frequency calibration (no other PM uses this approach). In your 5 mile ride, the SRM calibration is wrong, causing DFPM watts in PP to be way too low (133W for an average bike speed of 19.4 mph is low).
To use your unit the way you want, be 100% positive that your PP is attached securely and can't rotate, and make sure you follow carefully the SRM calibration procedure outlined in the AeroPod instructions (you are using PP the same thing).
1) In the 14 mile ride, you used the "Check Calibration" procedure to tweak your ride. That's OK, except...
The original, untweaked ride file shows that you bumped your unit at the 8 minute mark, causing slope to go very negative. Isaac does its best to fix this, but the bumped section (from minute 8 to 18) has really wacky slope and watts. In fact, it looks like, for most of the ride, your PP was not mounted in a stable position.
2) Your 14 mile ride also shows that wind is too high. The Check Calibration feature fixes this
3) It sounds like you have an SRM. These are super-tricky to calibrate, because of their ancient method of slope-frequency calibration (no other PM uses this approach). In your 5 mile ride, the SRM calibration is wrong, causing DFPM watts in PP to be way too low (133W for an average bike speed of 19.4 mph is low).
To use your unit the way you want, be 100% positive that your PP is attached securely and can't rotate, and make sure you follow carefully the SRM calibration procedure outlined in the AeroPod instructions (you are using PP the same thing).
John Hamann
Re: What's happened here?
I have both P1s and SRMs on the TT bike. I paired the P1s and speed sensor with the AeroPod on a different bike then moved them across to the P3C.
What I have been doing is running the SRMs to a PC8 headend and using the P1s with the AeroPod. The front wheel speed sensor transmits to both the PC8 and the AeroPod.
That glitch was probably a braking event then? I'm guessing. I normally can do laps without using the brakes.
>> 133W for an average bike speed of 19.4 mph is low
How about 178watt for 25mph in a 25 mile time trial
I'm normally seeing a CdA of around 0.1850 on my P3C with skin suit and TT helmet.
These tests are with tight road top and shorts and using ENVE 7.8 front an back rather than a Super9 at the back so I would expect to see around 0.1950 as the CdA. The surface is consistent and quite grippy as it's a crit circuit. With 5000TL tubeless the Crr is about 0.3500 with a tyre temperature of 35'C. It's been very sunny here (!)
What I have been doing is running the SRMs to a PC8 headend and using the P1s with the AeroPod. The front wheel speed sensor transmits to both the PC8 and the AeroPod.
That glitch was probably a braking event then? I'm guessing. I normally can do laps without using the brakes.
>> 133W for an average bike speed of 19.4 mph is low
How about 178watt for 25mph in a 25 mile time trial
I'm normally seeing a CdA of around 0.1850 on my P3C with skin suit and TT helmet.
These tests are with tight road top and shorts and using ENVE 7.8 front an back rather than a Super9 at the back so I would expect to see around 0.1950 as the CdA. The surface is consistent and quite grippy as it's a crit circuit. With 5000TL tubeless the Crr is about 0.3500 with a tyre temperature of 35'C. It's been very sunny here (!)