power spikes

Back by popular demand, the general all-things Road forum!

Moderator: robbosmans

User avatar
pdlpsher1
Posts: 4016
Joined: Thu Jul 19, 2012 6:09 pm
Location: CO

by pdlpsher1

I'm running a DFour and a 520. No weird power spikes on my past four rides. I'm now curious to find out if the 520 is somehow responsible....

by Weenie


Visit starbike.com Online Retailer for HighEnd cycling components
Great Prices ✓    Broad Selection ✓    Worldwide Delivery ✓

www.starbike.com



are
Posts: 147
Joined: Fri Sep 05, 2008 1:15 am
Location: Los Angeles

by are

Just to follow-up on this ... turned off the torque measurement in the p2m and now everything is fine; no weird power spikes captured by the Edge 520.

TobinHatesYou
Posts: 12457
Joined: Mon Jul 24, 2017 12:02 pm

by TobinHatesYou

Do you mean Torque Effectiveness? You can’t disable torque measuring on a power meter because, well, power is torque x velocity.

Keep an eye on your data to see if the spikes are truly gone. There’s no reason why the on/off status of advanced metrics like Torque Effectiveness or Pedaling Smoothness would affect power measurement accuracy. Those values are calculated well downstream.

refthimos
Posts: 411
Joined: Fri May 25, 2012 6:02 pm

by refthimos

Found this thread because I've been getting some 1 second power spikes with my Power2Max NG. What is it that I need to disable? There seemed to be a little confusion/ambiguity earlier in the thread.
EVO1 | 5.37kg
EVO3 (sold) | 6.51kg
EVO4 | build thread coming soon
S5 Disc
SystemSix (sold) | 8.01kg
P5 Disc | heavy but fast

mrlobber
Posts: 1928
Joined: Sat Oct 23, 2010 9:36 am
Location: Where the permanent autumn is

by mrlobber

refthimos wrote:
Tue Oct 16, 2018 6:49 pm
Found this thread because I've been getting some 1 second power spikes with my Power2Max NG. What is it that I need to disable? There seemed to be a little confusion/ambiguity earlier in the thread.
Anything not directly related to basic power measurement, i.e. Pedaling Smoothness, Torque Effectiveness etc.

I was also getting spikes on two different Garmin units on my P2M NG, disabled those metrics above through P2M's mobile app, and no spikes ever since.
To verify if it is Garmin or your power meter issue, look at raw data at recording interval (usually 1 sec): if no cadence is present at a power spike, it is Garmin fault since power meter by definition cannot calculate (and broadcast) power without cadence.

Some Garmin units are notoriously bad at receiving ANT+ signals due to stupid antenna placements, to the point they start "inventing" received data themselves. My Fenix is one of these beasts, and 10cm difference in distance to the bottom bracket (put it on stem or on wrist) can mean full power data or less than half of actual data with extended periods of dropouts.
Minimum bike categories required in the stable:
Aero bike | GC bike | GC rim bike | Climbing bike | Climbing rim bike | Classics bike | Gravel bike | TT bike | Indoors bike

bremerradkurier
Posts: 419
Joined: Mon Jun 13, 2016 4:18 pm

by bremerradkurier

My Bryton head unit pulling data from a Stages left arm will display a max power at 65536W but shows the more believable ~1000-1400W figure on the actual .fit files.

Post Reply